19971044 Ver 1_COMPLETE FILE_19950429

`State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
Ar?
DEN R
March 13, 1998
MEMORANDUM
To: Lisa Martin
Through: John Dorney
From: Eric Galamb,,?q
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land use in the watershed varies from rural farmland to highly urbanized.
The middle watershed is urbanized. The lower watershed is mostly rural and the upper
watershed is undergoing a rapid transition from farmland and forest to residential and
commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between-Black Creek Road and Tarboro Street: -
The COE studied structural and non-structural measures to address the flooding problem.
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofing were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore an
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8; therefore, this was a very good day to observe the flooding problem.
Environmental Sciences Branch • 4401 Reedy Creek Road Raleigh, North Carolina 27607. ;
Telephone [phone] FAX # [phone]
An Equal Opportunity Affirmative Acflon Employer 50% recycled/10% post consumer paper
According to the EA, the main flooding problem is a result of the blockage caused by the
CSX railroad causeway just upstream of US 301. Localized flooding occurs upstream of
the project .also due to an inadequately sized culvert at Kincaid Street. The COE has no
plans to address the observed flooding problem.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE procedures prohibit any increase in the downstream hydrograph. DWQ does
not oppose the installation of an additional culvert; however, the culvert should be
designed so that it is in the dry during normal flow. Otherwise the stream morphology
(width to depth ratio) of the existing channel will be unbalanced resulting in bank erosion,
sediment deposition and:other deleterious effects on water quality.
Due to the prohibition of increasing the hydrograph's peak, the COE investigated methods
channel widening was selected by the
This includes mature
-
Basin. The Neuse River Nutrient Sensitive Waters Management Strategy Rules (Neuse
rules) were recently enacted to prevent the removal of existing riparian forest vegetation in
the Neuse basin with a few narrow exceptions (copy sent to Coleman Long and John
Badin under separate cover). The rules define forest vegetation as, "The plants of an area
which grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street and therefore would be subject to the Neuse rules. Forest
vegetation is lacking between Phillip Street and Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Select cutting (the
removal of obstructions) would be acceptable. Snagging (the removal of a tree or a part
of the tree that protrudes above the surface in the body of water) may not be acceptable
except as outlined below. Rule NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of
individual trees that are in danger of causing damage to dwellings, other structures or
contribute to bank erosion. For the portion of the project that we transversed, we located
only one tree that was causing bank erosion because of its position in the stream channel.
The Neuse rules would allow for this individual tree to be removed but would not allow
additional snagging unless the COE could document that other trees are damaging the
stream channel.
Due to our Neuse and wetland rules, the project as proposed would not receive a 401
Water Quality Certification. Since COE procedures prohibit an increase in the
downstream hydrograph, we must revisit acceptable alternatives to reduce the hydrograph
and be in compliance with all rules.
One cannot completely understand the processes that are shaping and influencing a stream

without data collection and interpretation. Dave Rosgen has developed a stream
classification system so that one can extrapolate data and predict process responses
(Rosgen, 1994). Most Federal and State agencies in NC are beginning to use this
classification system to solve similar problems with stream flow. The benefit of using
Rosgen's classifications is that one must thoroughly study and understand the stream's
current condition so that it can be matched to its hydrological potential- This method
should be used and incorporated in a revised document.
Whatever activities are undertaken by the COE, they will be short-lived without
substantial changes in land development in the City of Wilson. Land use practices that add
extensive pavement without design to alleviate impacts to stream channels cannot be
mitigated by structural additions or modifications to stream channels (Stream System
Technology Center, 1985). For instance, last year the City issued a building permit in the
floodplain at Forest Hills Road and Little Hominy Swamp. Encroachments such as this
remove storage capacity of the floodplain, which aggravates the downstream flooding
problem. Major commercial and residential construction has occurred in the watershed
even with the knowledge of the downstream flooding problems. Plazas at the north side
of the intersection of Forest Hills Road and US 264 have been constructed without the use
of stormwater controls. The removal or elimination of land use activities that cause
adverse impacts to riparian and aquatic ecosystems are of the highest priority if restoration
is to be accomplished (Stream System Technology Center, 1985).
The document states that 297 residences and 45 commercial buildings are sited in the 100-
year floodplain of Hominy Swamp. Many of the mobile homes at Black Creek Road have
been recently abandoned or relocated. This change should be reflected in the revised EA.
Please identify the number of residential and commercial structures below the railroad
causeway that are now occupied and regularly flooded within the 100-year floodplain.
The COE indicated during our site visit that the City of Wilson is studying the flooding
problem at Kincaid Avenue. Again due to increased urban development, the culvert at
Kincaid Avenue and Hominy Swamp is probably undersized. The COE has separated this
flooding problem from their project. DWQ believes that these projects must be combined.
The flooding problem at Kincaid Avenue is significant. Therefore, this culvert will most
likely be replaced and the floodwaters backed up by the causeway will move into the
COE's project. Therefore, the COE should account for this additional water.
To ameliorate the flooding problems, alternatives in addition to the City of Wilson
adopting a stormwater management plan for the Hominy Swamp watershed must be
studied. DWQ proposed that the COE study areas where off-line detention ponds could
be constructed. One possible location for a pond would be at the Ridgewood Park off of
Phillip Street. There may be a need for several ponds in the watershed to completely solve
the flooding problem.
Another method to reduce the hydrograph may be to restore or create wetlands in the
watershed. Open land is present at Forest Hills Road and Little Hominy Swamp. Open
land is also present at the upper reaches of Big and Little Hominy Swamp. The City of
Wilson has not located have enough compensatory wetland mitigation for the impacts
associated with the Buckhorn Reservoir expansion. The wetland creation/restoration may
greatly assist the City to fulfill that need. This work could also be done in conjunction
with the Wetland Restoration Program. Mr. Ron Ferrell should be contacted (919-733-
5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration/creation, off-line ponds, retrofitting
impervious areas with stormwater ponds, and upstream dams should be considered in a
revised EA
-- -The City=ofilson'!astewaz?r-treatmen- t plant is -located_downstr-eam on Hominy---- -
Swamp . Please iscuss the eMcts of aft aftennatim"
- -
Please be aware that the Neuse rules-have basinwide stormwater requirements (NCAC 2B
.0235) . The City of Wilson will be required to submit a local stormwater management
plan to control nutrients. The plan must address nitrogen reductions for existing and new
development. All new development is required to have no net increase in peak flow
leaving he site from the DredeveloDment conditions. The Dlan must also find locations for
potential stormwater retrofits. These requirements should indirrec^- y asst
reducing the future flooding problems in the Hominy Swamp watershed.
Due to the significant issues listed above, DWQ requests that a revised EA be written for
this project. The revised EA should discuss increasing the flood elevation downstream
from techn.i al and legal perspectives. Otherwise SWQ requests that an EIS be prepared
for this project- The project sponsor is reminded that the 401 Certification would be
denied as currently proposed. Questions regarding the 401 Certification should be
directed to Eric Galamb (733-1786) in DWQ's Water Quality Non-Discharge Branch.
References:
Rosgen, David L. 1994. A Classification of Natural Rivers. =- Catena (22)- pp. 169-199. - -
Stream System Technology Center. October 1985. Artificial Stream Restoration -
Money Well Spent or an Expensive Failure? Stream Notes.
Cc: Greg Thorpe, DWQ Planning
Owen Anderson, WRC
Howard Hall, USFWS
Ron Ferrell, WRP

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E.,
MEMORANDUM
NCDENR
NORTH CAROLINA DEPARTMENT OF
Direch 11, RONMENT AND NATURAL RESOURCES
To: Michelle Suverkrubbe
Through: John Dorn
From: Eric G mf?
l
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land use in the watershed varies from rural farmland to highly urbanized.
The middle watershed is urbanized. The lower watershed is mostly rural and the upper
watershed is undergoing a rapid transition from farmland and forest to residential and
commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between Black Creek Road and Tarboro Street.
The COE studied structural and non-structural measures to address the flooding problem.
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofing were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore an
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8. Therefore, this was a very good day to observe the flooding problem.
?R+
s;
Division of Water Quality • Non-Discharge Branch
4401 Reedy Creek Rd., Raleigh, NC 27607 Telephone [phone] FAX # [phone]
An Equal Opportunity Affirmative Action Employer • 50% recycled/10% post consumer paper
. :.
According to the study, the main flooding problem is a result of the blockage caused by
the CSX railroad causeway just upstream from US 301. Localized flooding occurs
upstream of the project also due to an inadequately sized culvert. The COE has no plans
to address the observed flooding problem upstream of the City Park adjacent to Ripley
Road.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE procedures prohibit any increase in the downstream hydrograph. DWQ does
not oppose the installation of an additional culvert. However, the culvert should be
designed so that it is in the dry during normal flow. Otherwise the stream morphology
(width to depth ratio) of the existing channel will be unbalanced resulting in bank erosion,
sediment deposition and other deleterious effects on water quality.
Due to the prohibition of increasing the hydrograph's peak, the COE investigated methods
to reduce it. Clearing and snagging coupled with channel widening was selected by the
COE as a means to ameliorate the hydrograph. Hominy Swamp is in the Neuse River
Basin. Recently enacted rules (copy sent to Coleman Long and John Badin under separate
cover) prevent the removal of existing riparian forest vegetation in the Neuse basin with a
few narrow exceptions. The rules define forest vegetation as "The plants of an area which
grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
This includes mature and successional forests as well as cutover stands".
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street. Forest vegetation is lacking between Phillip Street and
Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Clearing (the removal of
obstructions) would be acceptable. Snagging (the removal of a tree or a part of the tree
that protrudes above the surface in the body of water) may not be acceptable except as,
outlined below. Rule NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of individual
trees that are in danger of causing damage to dwellings, other structures contribute to
bank erosion. For the portion of the project that we transversed, we located only one tree
that was causing bank erosion because of its position in the stream channel. The Neuse
buffer rules would allow for this individual tree to be removed but would not allow
additional snagging unless the COE could document that other trees are damaging the
stream channel.
Due to our rules, the project as proposed would not receive a 401 Water Quality
Certification. COE procedures prohibit an increase in the downstream hydrograph.
Therefore, we must revisit acceptable alternatives to reduce the hydrograph and be in
compliance with all rules.
One cannot completely understand the processes that are shaping and influencing a stream
r ,
I It
associated with Buckhorn Reservoir expansion. The wetland creation/restoration may
greatly assist the City to fulfill that need. This work could also be done in conjunction
with the Wetland Restoration Program. Mr. Ron Ferrell should be contacted (919-733-
5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration, off-line ponds, retrofitting impervious
areas with stormwater ponds, and upstream dams should be considered in a revised EA.
The City of Wilson's wastewater treatment plant is located downstream on Hominy
Swamp. Please discuss all impacts to this treatment plant from all alternatives.
Please be aware that the Neuse rules have basinwide stormwater requirements (NCAC 2B
.0235). The City of Wilson is required to submit a model local stormwater management
plan to control nutrients by August 1, 1999. The model plan must address nitrogen
reductions for existing and new development. All new development is to have no net
increase in peak flow leaving the site from the predevelopment conditions. The plan must
also find locations for potential stormwater retrofits. These requirements should indirectly
assist the COE in reducing the future flooding problems in the Hominy Swamp watershed.
Due to the significant issues listed above, DWQ requests that a revised EA be written for
this project. The revised EA should discuss increasing the flood elevation downstream
from technical and legal perspectives. Otherwise SWQ requests that an EIS be prepared
for this project. The project sponsor is reminded that the 401 Certification would be
denied as currently proposed for reasons described above. Questions regarding the 401
Certification should be directed to Eric Galamb (733-1786) in DWQ's Water Quality Non-
Discharge Branch.
References:
Rosgen, David L. 1994. A Classification of Natural Rivers. Catena (22) pp. 169-199.
Stream System Technology Center. October 1985. Artificial Stream Restoration -
Money Well Spent or an Expensive Failure? Stream Notes.
Cc: Greg Thorpe, DWQ Planning
Owen Anderson, WRC
Howard Hall, USFWS
Ron Ferrell, WRP

MAR 1 .? URI
I States Department of the Interior
FISH AND WILDLIFE SERVICE
Raleigh Field Office
Post Office Box 33726
Raleigh, North Carolina 27636-3726
March 11, 1998
Mr. John Dorney
N.C. Division of Environmental Management
Post Office Box 29535
Raleigh, North Carolina 27626-0535
Dear Mr. Dorney:
ffp ;;;yyy U ?
I
?,YET1?33:DGOLITi'J
1A?fcrZ4.?;. ..-
Enclosed is the U. S. Fish and Wildlife Service's Final Fish and Wildlife Coordination Act Report
for the Hominy Swamp - Flood Damage Reduction Project, City of Wilson, Wilson County,
North Carolina. The report identifies baseline fish and wildlife resources in the general study
area, discusses potential impacts to these resources, and offers recommendations to the
Wilmington District, U. S. Army Corps of Engineers, for use in project plans.
This office released a draft report on this project in September 1995. Subsequently the project
was placed in an inactive status until mid-1997. This report was extensively revised over the past
four months based on comments received on the draft report from state resource agencies. The
North Carolina Wildlife Resources Commission (NCWRC) has concurred with the findings and
recommendations in the final report. A copy of the letter of concurrence from the NCWRC is
included as a part of this report.
If you have any questions or comments, please contact Howard Hall at 919-856-4520, ext. 27.
Sincerely,
John M. Hefner
Field Supervisor
FW S/R4:HHall:3/ 11 /98: WP: A:ffwca.3 98
HOMINY SWAMP
FLOOD DAMAGE REDUCTION PROJECT
FINAL
FISH AND WILDLIFE COORDINATION ACT REPORT
Prepared by
Howard F. Hall
Under the Supervision of
John M. Hefner
Supervisor
Released by
U. S. Fish and Wildlife Service
Raleigh Field Office
Raleigh, North Carolina
March 1998
• 'a;,
- An
® North Carolina Wildlife Resources Commission
512 N. Salisbury Street, Raleigh, North Carolina 27604-1188, 919-733-3391
Charles R. Fullwood, Executive Director
March 2, 1998
MEMORANDUM
TO: Howard Hall
United States Fish and Wildlife Service -
FROM: Franklin T. McBride, Manager
Habitat Conservation Program
SUBJECT: FWCA Report for Hominy Swamp Project, Wilson County, North Carolina
The North Carolina Wildlife Resources Commission concurs with the findings and
recommendations presented in the Hominy Swamp Flood Control Project Fish and Wildlife'
Coordination Act Report.
Thank you for the opportunity to review and comment on the report.

t'°M - 3 1998
10
J
r

EXECUTIVE SUMMARY
Planning information pursuant to the U.S. Fish and Wildlife Service's responsibilities is provided
under the general authority of the Fish and Wildlife Coordination Act, as amended (48 Stat. 401;
16 U.S.C. 661 et seq.) and the FY95 Scope of Work Agreement for the study of the Hominy
Swamp Flood Control Project conducted by the Wilmington District, U. S. Army Corps of
Engineers (Corps). The Hominy Swamp Project was authorized within the Senate Public Works
Committee Resolution of April 15, 1966 and House Document 175/89. The purpose of the
project is to reduce flood damage along portions of the waterway within the City of Wilson,
Wilson County, North Carolina. This report constitutes the Service's formal report required
under Section 2(b) of the Fish and Wildlife Coordination Act (op. cited).
The Hominy Swamp study area extends from its headwaters near the Wilson County Airport
south to its confluence with Contentnea Creek. The watershed consists of approximately 9,500
acres. Since 1978, urban and residential development has significantly reduced the proportion of
natural and agricultural land. Urbanization has adversely affected the aquatic, riparian, and
floodplain areas of Hominy Swamp which serve as fish and wildlife habitat. Previous
channelization, channel clearing by the City of Wilson, and intense, rapid urban and agricultural
runoff create poor quality aquatic habitat conditions and low species diversity.
The land surrounding the section of Hominy Swamp under study is being developed at a rapid
rate. The development of new residential and commercial properties is resulting in an increase in
the amount of impermeable surfaces in the watershed and associated increases in stormwater run-
off. The channel has been previously modified to enhance stormwater drainage of the
surrounding urban and residential lands. The creek's water quality and availability of aquatic
habitat is poor. There are currently only limited existing biological resources of concern. The
opportunity for enhancing aquatic habitat is limited due to the continual development of the
watershed outside of the study area. However, the Hominy Swamp watershed offers
opportunities for implementing fish and wildlife habitat conservation, restoration, and
enhancement measures.
Hominy Swamp does provide limited support for adaptable invertebrates. The presence of some
vegetation and a limited invertebrate fauna suggest that Hominy Swamp can support some
vertebrate species. Several species of fish have been found in the project area. Some habitat
exists for amphibians, reptiles, birds, and mammals.
Three Federally-listed species have been reported to occur in Wilson County. These species are
the red-cockaded woodpecker (Picoides borealis), Michaux' sumac (Rhus michauxii), and the
dwarf wedge mussel (Alasmidonta heterodon). All are listed as federally-endangered. Surveys
done by the Corps in the project area did not find the dwarf wedge mussel.
Even without the proposed flood control projects in the Hominy Swamp watershed, the future of
the existing fish and wildlife resources would be uncertain. Increased human population and
r
development are likely to further degrade both aquatic and riparian habitats along Hominy
Swamp.
Early flood control plans released in 1968 consisted of 5.1 miles of channel improvements to be
done in two sections. In the southern section of 3.4 miles the existing channel would be enlarged
to a 35-foot bottom width with 1:1 side slopes and unspecified deepening. In the northern
section of 1.7 miles the existing channel would be enlarged to a 30-foot bottom width with 1:1
side slopes and unspecified deepening.
The scale of the project currently under consideration has been reduced. The total project length
is 2.1 miles. In the southern section of approximately 0.9 mile, work would be limited to
clearing and snagging the existing channel. The channel in the remaining 1.2 miles would be
widened to 25 feet. A 12-foot diameter' culvert would be bored and jacked through the fill under
the CSX railroad main line to make the improved conditions continuous. Approximately 40,000
cubic yards of material from the channel would be removed and transported to an upland
disposal site.
There are potential adverse environmental impacts associated with the proposed project. Tree
and shrub removal on the rights of way and replacement with a landscaped vegetation maintained
by periodic mowing can be expected to reduce wildlife species diversity and population
densities. Channelization would reduce allochthonous (external) inputs of important biochemical
energy sources. The removal of canopy cover would increase water temperatures and reduce the
concentrations of dissolved oxygen. A reduction in dissolved oxygen would stress aerobic,
aquatic organisms. The project could reduce water storage in the watershed and produce harmful
low flow conditions during drought periods. Reduced water storage could also lead to changes in
plant communities in the watershed. The project could lead to increased sediment deposition
downstream from the project area. A long term impact of the project could be increased
development in the floodplain which would further eliminate and fragment existing, natural plant
communities. Increased development would increase stormwater runoff which could lower
water quality and increase erosion.
The potential adverse impacts of the project could be minimized by incorporating conservation
measures into project design and construction techniques. Riparian revegetation may be the most
significant opportunity to rectify impacts. Trees planted on the stream banks would provide
wildlife habitat and much needed stream shading. Other conservation measures include limiting
the removal of stream side vegetation, clearing and stabilizing banks in stages, removing all
sediment to an upland disposal site, creating and maintaining an effective sediment trap
downstream from the project area.
The Service believes that the potential adverse environmental effects of the proposed flood
control project can be avoided and/or minimized by the use of certain design features and
construction techniques. Therefore, the Service has developed, in cooperation with the North
Carolina Wildlife Resources Commission and other resource agencies, a number of specific
ii

r
h
recommendations to both minimize adverse impacts on fish and wildlife resources and to
facilitate the enhancement of these resources. These recommendations are:
The proposed project, by itself, would not provide a long-term, effective solution to
flooding along Hominy Swamp in the City of Wilson. Therefore, the Corps should
integrate any construction along the reach under consideration with a comprehensive
flood control program which includes: (1) limitations on development within the 100-
year floodplain; (2) the creation of stormwater retention ponds within existing
development; (3) the retrofitting of large areas of impervious surface to increase water
storage capacity and, (4) the use of open areas, such as parks along Hominy Swamp, to
recreate floodplains, especially forested wetlands. While the Corps may not have the
authority to require the implementation of a flood control program, the final
environmental documentation should clearly outline the procedures necessary in achieve
effective, long-term flood control.
2. The Corps should ensure that the project does not result in adverse impacts to wetlands
due to the loss of hydrology associated with a lowering of water tables following efforts
to expedite flood flows.
3. Any in-channel modifications from the CSX railroad spur to Goldsboro Street (the
northern area of the proposed project) should be limited to the removal of isolated areas
of significant, in-channel sediment accumulation. Since any channel widening would
only reduce the sediment carrying capacity of the stream during baseflow conditions and
lead to increased sediment deposition, there should be no removal of material to widen
the existing channel.
4. In the southern part of the project area (CSX railroad spur to Blackcreek Road) the
removal of completely detached material is acceptable. However, the removal of any
plant material, either living or dead, which is attached to the bank or stream channel
(snagging) must comply with current regulations of the North Carolina Division of Water
Quality which provides special buffer rules for the Neuse River Watershed. All debris
removed from the project area should be transported to an approved upland site for
disposal.
5. Flow blockage at the railroad causeway should not be addressed with the proposed
addition of a second, 12-foot culvert. Efficient movement of flood water should be
achieved by one, or preferably more, new water conveyance structures at elevations
corresponding to flood stage. In order to minimize excessive sedimentation during period
of baseflow, the new conveyance structures should be at an elevation where they would
remain dry during baseflow periods.
6. In order to minimize erosion during construction, any work along the banks should be
conducted in stages. Each bank segment should be stabilized prior to initiating
iii
construction on the adjacent segment. All spoil removed from the project area should be
transported to an approved, upland site for disposal.
7. To protect downstream aquatic habitats from sedimentation problems caused by project
construction, the proposed sediment trap to be created downstream of the project should
be maintained by cleaning during construction and for a specified period of time
thereafter to allow the banks to be stabilized with vegetation. Cleaning should be
undertaken whenever the trap becomes half full. This cleaning would insure that sudden
periods of heavy rain would not cause the trap to overflow.
8. All areas cleared for construction should be landscaped in order to provide maximum
wildlife habitat and stream shading. Mast-producing, hardwood trees, such as oaks
(Quercus spp.) and hickories (Carya spp.), spaced widely along this stream bank would
shade the stream and help stabilize the banks without causing significant impediments to
water flow in the channel. The Corps should work with the local sponsor to develop a
maintenance program which enhances wildlife habitat. One beneficial aspect of such a
plan would be to schedule the mowing of herbaceous vegetation on bank areas at a
minimum interval of once during the midsummer every two years.
The Service recommends that these conservation measures be incorporated into project plans for
the Hominy Swamp Flood Control Project. The full incorporation of these measure would not
only minimize harm to fish and wildlife resources, but would also greatly enhance these
resources within the project area.
iv
TABLE OF CONTENTS
Page
Executive Summary ............................................................ i
Table of Contents ..............................................................v
Introduction ..................................................................1
Purpose, Scope, and Authority .............................................. 1
Prior Studies ............................................................1
Study Area Description ......................................................... 3
Fish and Wildlife Service Concerns and Planning Objectives ........................... 4
Evaluation Methods ............................................................6
Existing Fish and Wildlife Resources .............................................. 6
General Fish and Wildlife Resources ......................................... 6
Federally Endangered and Threatened Species ................................. 7
Future Fish and Wildlife Resources without the Project ................................ 8
Description of Alternatives Considered ............................................. 9
Selection of the Preferred Alternative .............................................. 9
Potential Impacts of the Preferred Alternative ....................................... 13
Direct Impacts .........................................................13
Indirect Impacts ........................................................14
Cumulative Impacts ..................................................... 15
Summary of Impacts .................................................... 15
Fish and Wildlife Conservation Measures ......................................... 16
Recommendations ............................................................19
Summary of Findings and Service Position ......................................... 21
Literature Cited ..............................................................21
v
FIGURES
page
Figure 1. General location of the Hominy Swamp Flood Control Project, Wilson County,
North Carolina . ...................................................2
Figure 2. Project area for the Hominy Swamp Flood Control Project, Wilson County, North
Carolina. The area from Point A (SR 1606, Black Creek Road) to Point B (trestle
of railroad spur) would be cleared and snagged. The channel from Point B to
Point C (bridge for Goldsboro Street) would be widen. At Point D (fill under
CSX Railroad track) a new culvert would be installed. Source of base map:
Wilmington District, U. S. Army Corps of Engineers . .................... 10
Figure 3. Topographic map of the Hominy Swamp Flood Control Project, Wilson County,
North Carolina. Points A-D represent the same features as those in Figure 2... 11
vi
INTRODUCTION
Purpose. Scope, and Authority
The Corps of Engineers' planning for the proposed Hominy Swamp Flood Control Project,
Wilson County, North Carolina, is being carried out under general authority of Section 205 of the
Flood Control Act of 1948, as amended, (33 U.S.C. 701s). The specific study was part of an
authorization within the Senate Public Works Committee Resolution of April 15, 1966 and
House Document 175/89. This report is submitted in accordance with provisions of the Fish and
Wildlife Coordination Act (FWCA), as amended (48 Stat. 401; 16 U.S.C. 661 et, seq.). This
report constitutes the Service's formal report required under Section 2(b) of the FWCA.
The Hominy Swamp Project has been proposed to reduce flood damage along portions of the
waterway within the City of Wilson, Wilson County, North Carolina (Figure 1). Hominy
Swamp is actually a stream on the upper edge of the coastal plain. There has been a persistent
problem of flooding along Hominy Swamp. This problem appeared to worsen during the 1960s.
Increased flooding may have resulted from land use changes in the basin above Wilson where
cropland and woodlands were converted to residential, commercial, and industrial uses. Annual
floods in the project area affect streets, parking lots, storage areas, and residential lawns and
gardens. Floods of an approximately 3-year frequency affect houses, warehouses, industrial
sites, commercial buildings, and streets.
The purposes of this report are to document the potential impacts of the proposed project on fish
and wildlife resources and provides recommendations to conserve and protect these resources.
For the purpose of this report, the study area is the bed, banks, and 100-year floodplain of
Hominy Swamp from the bridge at Goldsboro Street near the center of Wilson downstream to the
Bridge at Secondary Road (SR) 1606, Black Creek Road.
Prior Studies
Planning for this project has extended over many years. A Detailed Project Report was released
by the Corps on May 6, 1968. The project was originally linked to a similar flood control project
on Adkins Branch in Kinston, Lenoir County, North Carolina. On March 24, 1987, a Service
biologist visited the site to assess the fish and wildlife resources in the project area. On July 14,
1987, the Service issued a Planning Aid Report for the combined Adkins Branch/Hominy
Swamp Projects. In the early 1990s, the two projects were separated. On June 22, 1990, Corps
biologists surveyed the project area. This survey considered aquatic habitats and specifically
sought to determine whether the federally-endangered dwarf-wedge mussel (Alasmidonta
heterodon) was present. The Hominy Swamp project has now been reactivated. The Service
received a project description for the proposed work on May 22, 1995. The area was revisited by
a Service biologist on June 28, 1995 in order to assess fish and wildlife habitat characteristics.
1

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STUDY AREA DESCRIPTION
Hominy Swamp extends from its headwaters near the Wilson County Airport south to its
confluence with Contentnea Creek in Wilson County, North Carolina (Figure 1). The watershed
is approximately 9,500 acres in size and includes most of the western half of the City of Wilson.
Based on the classification given by Stanturf and Schoenholtz (1998, pp. 142-143), the project
area is a "minor bottom." Such areas have floodplains less than 1 km (0.6 mile) in width, and
their streams flood frequently but for a short duration. Sediment in minor bottoms reflect local
sources. The area surrounding such minor drainage is usually flat.
Based on 1978 maps by the U. S. Geologic Survey, land use was divided approximately equally
among urban areas, cleared and undeveloped land (mostly agricultural), and forested areas
(natural and residential). Since 1978, commercial construction and residential development have
significantly reduced the proportion of natural areas and agricultural, land. Urbanization also has
adversely affected the aquatic, riparian, and floodplain fish and wildlife habitats of Hominy
Swamp.
Previous channelization, channel clearing by the City of Wilson, and intense, rapid runoff from
impervious surfaces and agricultural lands create poor quality aquatic habitat conditions and low
species diversity. The stream bed is comprised of unstable and unconsolidated sand and silt. In
the more developed areas the channel is unvegetated and virtually free of snags and other debris.
Within the project area the stream channel varies from approximately 20 feet to 40 feet wide with
width generally increasing from north to south.
Stream banks are generally steep, sandy, stable, or moderately eroding. Banks increase in height
from approximately 4 feet upstream to approximately 8 feet at the downstream end of the study
area. Bank height reaches 15 feet in some locations where spoil from previous channelization
has been piled on the floodplain. This condition is particularly evident in the downstream half of
the study area. The City of Wilson has no stream bank maintenance program.
South of US 301 the banks are generally well-vegetated with dense, riparian shrub and canopy
layers which provide shading for the stream. Palustrine forested and other floodplain wetland
habitats exist in several areas along Hominy Swamp. The largest area of bottomland hardwood
forest exists on the floodplain south of the study area. This forest extends downstream from
Sewage Treatment Plant No. 2 to Contentnea Creek and becomes more narrow upstream of the
plant where it extends nearly to SR 1606. Other naturally vegetated forested wetland areas exist
between SR 1606 and US 301, principally on the west side of the creek and on both sides of the
area between Elizabeth Road and Raleigh Road. Except for the area south of Sewage Treatment
Plant No. 2, forested wetlands in the project area are isolated patches of habitat within an urban
setting. Most of the adjacent floodplain and upland areas are developed.
North of US 301 the banks have few, if any, mature trees. The banks have dense growths of
shrubs, vines, small trees, and herbaceous plants. In areas adjacent to residential property,
residents maintain the banks in short grasses.
FISH AND WILDLIFE SERVICE CONCERNS AND PLANNING OBJECTIVES
The involvement of the Service in this study is in response to a Congressional mandate through
the Fish and Wildlife Coordination Act (op. cited) which directs that the conservation of fish and
wildlife resources shall receive full and equal consideration and be coordinated with other
features of federal projects.
Fish, wildlife, and their habitats are valuable public resources which are conserved and managed
for the people by state and federal governments. If proposed land or water developments may
reduce or eliminate the public benefits that are provided by such natural resources, then state and
federal resources agencies have a responsibility to recommend means and measures to mitigate
such losses. In the interest of serving the public, it is the policy of the Service to seek to mitigate
losses of fish, wildlife, and their habitats and to provide information and recommendations that
fully support the nation's needs for fish and wildlife resource conservation as well as sound
economic and social development through balanced multiple use of the nation's natural
resources.
Nationwide, urban development of floodplains has had drastic impacts on fish and wildlife
resources (Leedy et al. 1981). Homes, factories and businesses have been built on floodplains
with little regard for the dangers of flooding. When the waterways inevitably overflow their
banks and cause property damage, the solution to the problem has often been stream
channelization. These efforts to "control" flooding have led to increased downstream flooding
and to the loss of riparian forests and the conversion of natural stream beds with a diversity of
aquatic habitats to wide, flat-bottom ditches bordered by maintained herbaceous vegetation.
With better planning, however, streams and riparian forests can be important features of a city's
plan for parks, natural areas, and open space. Enhanced riparian areas can provide fish and
wildlife habitats, recreation areas, and enhanced urban aesthetic quality (Leedy et al. 1978).
Land within the Hominy Swamp watershed is being developed at a rapid rate. The development
of new residential and commercial properties is resulting in an increase in the amount of
impermeable surfaces in the watershed and associated increases in stormwater run-off. Roads,
street gutters, roof downspouts, paved parking areas, and storm drains move water downhill
faster than would occur on natural slopes. The speeding of runoff means that a given volume of
water must be discharged in a shorter period of time which results in an increase of peak
discharge (Leopold 1994, p. 119). The Hominy Swamp channel has been previously modified
to enhance storm drainage of the surrounding urban and residential lands. The creek's water
quality and availability of aquatic habitat is poor. There are currently only limited, existing
biological resources of concern. The opportunity for enhancing aquatic habitat is limited due to
the continual development of the watershed outside of the study area.
4
The Service is concerned that the proposed project does not offer a long-term solution to
flooding problems in Wilson. Development within the 100-year floodplain of Hominy Swamp,
the removal of natural wetlands, and the creation of large areas of impervious surface (e.g.,
parking lots) are contributing factors to flooding in the project area. The proper management of
these contributing factors within a comprehensive stormwater management plan would minimize
the need for proposed modifications of the existing stream channel. While development outside
the project area is not under the jurisdiction of the Corps, the Corps' planning documents could
outline the steps which are necessary for effective, long-term flood control.
Aquatic habitat and water quality of Hominy Swamp will not improve without significant
instream habitat modifications and the initiation of a comprehensive watershed management plan
directed towards the elimination of polluted discharges and sediment deposition in the creek
channel. However, some limited planning opportunities do exist to ensure that the proposed
project does not produce any additional deterioration of fish and wildlife habitats.
As the Service stated in our Planning Aid Report of July 14, 1987, the Hominy Swamp
watershed offers opportunities for implementing fish and wildlife habitat conservation,
restoration, and enhancement measures. Attainment of these goals is possible if they are
adequately addressed in the planning process. The planning objectives of the Service for this
project include:
Restoration of water quality through local control of effluent discharge and stormwater
runoff from contaminated sources such as roads and parking lots;
2. Reduction of stream bed siltation through control of upland stream bank erosion;
3. Reduction of stormwater discharge intensity by installing retention facilities for
impervious surfaces of significant area;
4. Revegetation of cleared stream banks with trees and shrubs for bank stabilization, stream
shading, and riparian wildlife habitat enhancement;
5. Enhancement of aquatic habitat quality by providing structures for habitat diversity and
water aeration;
6. Development of an urban greenway system along Hominy Swamp by permanently
protecting existing natural areas and connecting them with revegetated and permanently
protected riparian habitat corridors;
7. Avoidance of all discharges of fill in wetlands; and,
8. Restoration of floodplain hydrologic connections between Hominy Swamp and its lower
reaches by removing relict piles of discharged dredged material.
In accordance with the Fish and Wildlife Coordination Act, as amended, these planning
objectives should be given full and equal consideration with other features of the Hominy
Swamp Project.
EVALUATION METHODS
Descriptions of anticipated impacts to fish and wildlife resources are derived from previous
studies on this and other projects, published literature, personal communications with other
biologists and planners, and qualitative information obtained during site visits by Service and
Corps biologists. Service biologists visited the site on March 24, 1987 and again on June 28,
1995. Corps biologists conducted an aquatic habitat survey in the project area on June 22, 1990.
As part of the preparation for this final report, an on-site visit was made on January 8, 1998. At
this meeting representatives of the Corps, the Service, the North Carolina Wildlife Resources
Commission, and the North Carolina Division of Water Quality discussed the flooding problems
of the area, the factors contributing to this problems, the proposed project, and alternatives
methods of flood control.
In this report plant nomenclature follows Radford et al. (1968); fish nomenclature follows Rohde
et al. (1994); bird nomenclature follows Potter et al. (1980); and mammal nomenclature follows
Webster et al. (1985).
EXISTING FISH AND WILDLIFE RESOURCES
General Fish and Wildlife Resources
Prior to extensive development the project area probably supported the wildlife community
characteristic of a minor alluvial floodplain. These areas include some of the most productive
and valuable fish and wildlife habitats in the country (Hodges 1998, p. 335). Factors
contributing to high quality wildlife habitat include fertile alluvial soil, abundant water, high-
quality food of great variety, relative freedom from fire, access to nearby agricultural fields, and
good escape cover. Amphibians benefit from the moist conditions provided by a closed canopy
and abundant leaf litter (Wigley and Lancia 1998, p. 228), and alluvial floodplain forests support
a large number of migratory bird species during the winter (Wigley and Lancia 1998, p. 222).
Forested wetlands serve as fish nursery areas (Hoover and Killgore 1998, p. 250)
The project area has been impacted, to various degrees, by development within the City of
Wilson. The northern part of the area (north of US 301) has been highly altered by this
development. While the southern part shows less direct impact, any alterations of water quality
flow into this area would affect the habitat value of the area. Within the entire area there is
limited availability and diversity of structural habitat components. Aquatic organisms probably
suffer physical stress from intense flushing caused by stormwater runoff. Reaches without
riparian vegetation may have increased water temperatures resulting from increased solar
6
exposure. Higher water temperatures may create biochemical stress due to reduced levels of
dissolved oxygen. Inadequate natural water aeration further exacerbate problems associated with
low levels of dissolved oxygen.
Hominy Swamp does provide limited support for adaptable invertebrates. A survey by Corps
biologist in 1990 found three species of gastropods, but no bivalves were found. These species
were pewter physa (Physella heterostropha), creeping ancylid (Ferrissia rivularis), and bugle
sprite (Menetus dilitatus). These species are pollution tolerant organisms and have been noted to
occur in disturbed or degraded waters. The Corps report noted that the stream was severely
degraded, a condition resulting from past channelizations, severe sedimentation, and, probably,
poor water quality. A Service biologist noted several crayfish towers on the floodplain during
the site inspection in June 1995.
The presence of some vegetation and a limited invertebrate fauna suggest that Hominy Swamp
can support some vertebrate species. Fish surveys were conducted in the project area on May 1,
1987. These surveys found the eastern mosquitofish (Gambusia holbrooki), pumpkinseed
(Lepomis gibbosus), warmouth (Lepomis gulosus), bluegill (Lepomis macrochirus), green
sunfish (Lepomis cyancellus), and the American eel (Anguilla rostrata). One unidentified fish
approximately five to six inches long was observed in Hominy Swamp at its <Homonym>
intersect with Phillips Street during the site visit in June 1995.
The project site probably provides habitat for a limited number of amphibians and reptiles. The
riparian woodlands in the southern section appear suitable for species of frogs, toads,
salamanders, and snakes which are adapted to disturbed habitats.
Habitat for birds varies greatly between the northern and southern sections of the project area.
The wooded riparian areas of the southern section probably supports a wider diversity of birds
than the open, cleared areas of the northern section. Birds noted by Service biologists in the
southern section include the Carolina chickadee (Parus carolinensis), red-tailed hawk (Buteo
jamaicensis), common crow (Corvus brachyrhynchos). This section probably provides habitat
for birds adapted to isolated woodlands such as woodpeckers and flycatchers. The northern
section may support open area birds such as the sparrows, eastern meadowlark (Sturnella
magna), and red-winged blackbird (Agelaius phoeniceus).
The existing mammalian fauna is probably limited. The area may provide habitat for a diversity
of rodents and disturbed area species such as the opossum (Didelphis virginiana), gray squirrel
(Sciurus carolinensis), and raccoon (Procyon lotor). Data from site visits have included the
observation of the eastern cottontail rabbit (Sylvilagus jloridanus) and raccoon tracks.
Federally Endangered and Threatened Species
Service data for Wilson County indicate that three federally-listed species may occur in the
county. These species are the red-cockaded woodpecker (Picoides borealis), Michaux' sumac
7
(Rhus michauxii), and the dwarf wedge mussel (Alasmidonta heterodon). All are listed as
federally-endangered.
The red-cockaded woodpecker (RCW) nests in old growth pine stands in which understory
development has been suppressed. From the nesting area birds may forage in stands of pine or
pine-hardwoods which are at least 30 years old. Service biologists have not reported suitable
habitat for this species. The Corps has determine that the project is not likely to adversely affect
this species due to absence of suitable habitat in the project area (U. S. Army Corps of Engineers
[henceforth USACOE] 1997).
Michaux's sumac is a densely hairy shrub with erect stems which are one to three feet in height.
The species grows in sandy or rocky open woods in association with basic soils. The best
survival of the plant appears to be in areas of some form of disturbance has provided an open
area. The Corps has determine that the project is not likely to adversely affect this species due to
absence of suitable habitat in the project area (USACOE 1997).
The Corps performed field surveys for the dwarf wedge mussel in the project area during June
1990. These surveys did not find the dwarf wedge mussel or any other native bivalve. The
Corps has determined that the degraded conditions of Hominy Swamp preclude the presence of
this species. Therefore, the Corps has determined that the species is not likely to be adversely
affected by the project (USACOE 1997).
FUTURE FISH AND WILDLIFE RESOURCES WITHOUT PROJECT
Even without the proposed flood control projects in the Hominy Swamp watershed, the future of
the existing fish and wildlife resources would be uncertain. The City of Wilson had a
population of 36,930 in 1990 and an estimated population of 37,638 in 1993 (USACOE 1997).
The population of the area is growing very slowly.
The remaining agricultural and forested uplands will be under increasing development pressure.
Further development of uplands for residential, commercial, and industrial use may exacerbate
problems associated with stormwater runoff and water quality. Continuing stream bed siltation
and stream bank erosion may perpetuate reduced aquatic habitat quality. The development of
riparian and floodplain areas, if not locally regulated, is expected to contribute to the elimination
and fragmentation of fish and wildlife habitat. The elimination of remaining natural areas and
the associated habitat fragmentation can be expected to reduce resident wildlife populations and
diminish habitat quality for migratory species.
On the other hand, development by environmentally conscious developers, along with local
habitat protection efforts by the affected municipalities and residents could significantly restore
and enhance fish and wildlife habitats in the watershed. Water quality restoration and protection,
stormwater retention, erosion control, environmentally-acceptable stream bed and bank
8
stabilization, vegetation establishment, greenways, and natural area protection could improve the
quantity and quality of fish and wildlife habitats along Hominy Swamp.
DESCRIPTIONS OF ALTERNATIVES CONSIDERED
The flood control project for Hominy Swamp has been under consideration for many years.
Early planning apparently was conducted prior to 1968. The Corps issued a Detailed Project
Report on May 6, 1968. This report states that early consideration was given a variety of
projects such as a flood storage reservoir, dike protection, floodproofing, and channelization.
The document concludes that the best flood control plan consisted of 5.1 miles of channel
improvements to be done in two sections. A project area map provided by the Corps is given in
Figure 2. A topographic map of the project is given in Figure 3. In the northern section the
existing channel would be enlarged and slightly deepened to a 30-foot bottom width with 1:1
side slopes from the confluence of Big Hominy Swamp and Little Hominy Swamp (upper left of
Figure 2) downstream to Park Avenue, a distance of 1.7 miles. In the southern section the
existing channel would be enlarged and deepened to a 35-foot bottom width with 1:1 side slopes
from Park Avenue to a point 800 feet below the sewage outfall canal at Sewage Disposal Plant
No. 2 (lower right corner of Figure 3), a distance of 3.4 miles. The project would add a 12-foot
culvert at the Seaboard Coast Line Railroad crossing (Point D, Figure 2 and 3), replace the
existing structure at Phillips Street with a 35-foot clear-span bridge, widen the existing bridge at
Kincaid Street, lower four sanitary sewer crossings, and modify one sanitary sewer crossing. The
1968 plan also called for augmenting the channel improvement project with floodplain
regulations prohibiting buildings below the 100-year improved floodplain, an action that could
have been expected to significantly reduce the potential for flooding over the long-term.
A status report of Corps activities issued on February 1, 1977 noted that the Hominy Swamp
Project still consisted of a 5.1-mile urban channelization project. This report also notes that
several actions required completion before the Hominy Swamp Project could be constructed.
These actions included: (1) new assurance of cooperation from the local sponsor, the City of
Wilson; (2) floodway delineations along the project reach; (3) preparation of an environmental
statement; (4) a survey of the project right-of-way; and, (5) revise outmoded portions of project
specifications.
A status report from the Corps dated October 5, 1993 states that the Hominy Swamp Project
involves work along approximately 5 miles of the stream, but notes that "... the length
recommended for improvement will probably be much less." Plans for post-project channel
widths ranged from 25 to 40 feet. The report indicates that a description of the recommended
plan would be available shortly.
SELECTION OF THE PREFERRED ALTERNATIVE
On May 22, 1995, the Service received a copy of the revised project description for the Hominy
Swamp Flood Control Project. The revised plan is smaller in scope than the 1968 proposal. The
9

1
Figure 2. Project area for the Hominy Swamp Flood Control Project, Wilson County, North
Carolina. The area from Point A (SR 1606, Black Creek Road) to Point B (trestle of railroad
spur) would be cleared and snagged. The channel from Point B to Point C (bridge for Goldsboro
Street) would be widen. At Point D (fill under CSX Railroad track) a new culvert would be
installed. Source of base map: Wilmington District, U. S. Army Corps of Engineers
10
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Figure 3. Topographic map of the Hominy Swamp Flood Control Project, Wilson County, North
Carolina. Points A-D represent the same features as those in Figure 2.
11
current plan has considered benefit-cost analyses (John Baden, Corps of Engineers, personal
communication, June 28, 1995).
The preferred alternative consists of various channel improvements over approximately 2.1
miles. The downstream project boundary would be the bridge at Black Creek Road, SR 1606
(Point A, Figures 2 and 3). From this point clearing and snagging would extend upstream for
approximately 0.9 mile to the trestle on the railroad spur line (Point B, Figure 2 and 3). From the
trestle, the channel would be widened to 25 feet for a distance of 1.2 miles upstream to the bridge
at Goldsboro Street (Point C, Figures 2 and 3). A 12-foot diameter culvert would be bored and
jacked through the fill under the CSX railroad main line (Point D, Figures 2 and 3) to make the
improved conditions continuous.
Clearing and snagging would consist of removing debris and cutting of saplings and underbrush,
with a view toward maintaining the stability of the banks. Large trees would not be cut unless
they were leaning and in danger of falling into the channel, and thus becoming debris. Channel
widening would increase the channel bottom width to 25 feet. In addition, there would be a
deepening of 1 foot to 1.5 feet of the channel bottom over a reach of approximately 300 feet to
provide a continuous slope for the stream bottom. The location of this reach is from Ralston
Street, the street immediately north of the railroad spur trestle (Point B, Figures 2 and 3), to
approximately 200 feet below the trestle. In other parts of the project area minor areas of
sediment accumulation would be removed to create a relatively flat stream channel. Side slopes
would be 1H:1V. Approximately 40,000 cubic yards would be removed and transported to a
disposal area.
Project construction would generally be limited to one bank at any particular point, with the
working bank alternating from side to side to minimize impacts to existing features along the
stream. Excavation of both banks would be necessary in transition areas where the channel
modification switches for one bank to the other, and in any areas where slopes need dressing for
stability. Slope and stream bottom protection would be required immediately downstream of the
railroad culvert where velocities would otherwise result in erosion. A concrete apron would
extend approximately 5 feet from the outlets of the existing culvert and the new culvert. Riprap
would extend approximately 15 feet from the end of the concrete apron. From that point, riprap
would only be needed on the slopes and would extend another 30 feet. A total volume of about
150 cubic yards of riprap would be needed.
In general, a 30-foot wide right of way would extend from the top of the improved bank on either
side of the stream. The right of way would be narrower at any location where existing structures
are less than 30 feet from the improved top of bank. Rights-of-way would be used for project
construction, maintenance access, and for landscaping measures. Rights-of-way would be
cleared as needed to facilitate construction.
A sediment trap would be provided near the downstream end of the channel widening. This trap
would serve to prevent increased sediment resulting from the construction activities from being
12
carried downstream. The trap would consist of a deepened area within the stream bottom; no
riprap or outlet structures are planned. Dimensions of the sediment trap and construction details
would be determined during development of plans and specifications.
All maintenance on the project would be performed by the City of Wilson. Maintenance of
right-of-way corridors in the channel widening portion would likely consist of mowing at regular
intervals. In the area that is to be cleared and snagged, maintenance would consist of cutting
back and removing shoots from the stumps that would remain after initial clearing. In all areas,
any bank erosion would need repair and snags that fall into the stream or wash in from upstream
would be removed. Sediment collecting in the sediment trap would need to be removed until the
upstream banks stabilize.
Several upland disposal areas are under consideration. One area is near the junction of Raleigh
Street and Trinity. The sediment from Hominy Swamp would be placed on trucks and hauled to
the selected disposal site.
POTENTIAL IMPACTS OF THE PREFERRED ALTERNATIVE
Direct Impacts
Environmental impacts of stream channelization are described in detail by Simpson et al. (1982),
Maki et al. (1980), Marzolf (1978), and Keunzler et al. (1977). The most significant direct
impacts of the proposed project and the subsequent landscaping plan would be the loss of
riparian vegetation and the degradation of instream aquatic habitats in the project area and
downstream.
Terrestrial and semi-aquatic wildlife species can be expected to suffer some adverse impacts
from channelization. Invertebrate-rich leaf packs and dense riparian vegetation on stream banks
normally provide feeding, resting and reproductive habitats for toads, frogs, salamanders, snakes,
songbirds, shore birds, moles, shrews, rodents, and furbearers.
Tree and shrub removal on the rights-of-way and replacement with a landscaped vegetation
maintained by periodic mowing can be expected to reduce wildlife species diversity and
population densities (Simpson et al. 1982). Natural riparian vegetation provides a variety of bird
habitat components needed for perching, roosting, feeding, breeding, and nesting sites. Some
birds, such as the kingfisher, and the herons use riparian areas heavily; others, such as many of
the songbirds, use these areas during only part of the day, as watering sites, for example, or only
during seasonal migrations. Habitat alterations during construction could cause a decrease in
bird species diversity in the area. Reduction in canopy cover generally would lower the habitat
value of the area for some birds.
Channelization would reduce allochthonous input of an important biochemical energy source,
coarse particulate organic matter, which is mostly leaves and stems of trees and shrubs. The
13
microflora which invades the coarse particulate organic matter are food for a variety of
macroinvertebrates, which, in turn, support higher trophic levels (Marzolf 1978, Simpson et al.
1982). Channel widening would also reduce sources of tree limbs, trunks, and root masses which
are important organic inputs as well as structural components of stream habitats.
When bank clearing and channel widening results in a more open canopy, more sunlight reaches
the stream. Increased solar exposure usually results in higher water temperatures. Warmer water
will have lower dissolved oxygen concentrations than cooler water in a shaded stream. Reduced
dissolved oxygen make a stream less habitable for aerobic macroinvertebrates (Simpson et al.
1982). Increased solar exposure can exaggerate diurnal dissolved oxygen extremes by increasing
diurnal photosynthesis and nocturnal algal respiration. Nocturnal oxygen deficits caused by algal
respiration can stress aerobic organisms (Simpson et al. 1982), with adverse impacts throughout
the aquatic food chain.
Channelization, and the resulting drainage of riparian and floodplain areas, reduces water storage
and may result in the lowering of the water table. This, in turn, affects the recharge of streams
and may result in significant reduction of instream flow during drought periods. Fish and
wildlife communities along the waterway would be adversely affected by any significant,
instream water shortages.
Lowered water tables in riparian and floodplain areas and the resulting reduced stream flow
during drought periods may also result in further impairment of water quality. Municipal and
industrial waste discharges may be more concentrated in low flow periods and adversely affect
the aquatic ecosystem directly through toxic concentration of wastes an/or indirectly thorough
disruptions to algal production and aquatic respiration.
Erosion and sedimentation are among the most severe effects of channelization. Erosion
typically is caused by the interaction of vegetation removal and channel straightening.
Vegetation removal renders the banks unstable and vulnerable to increased stream flow velocities
and rainwater (Simpson et al. 1982). Channel straightening increases stream flow velocities and
the stream's sediment carrying capacity.
Indirect Impacts
The area in which fish and wildlife resources are affected by stream bank clearing and
channelization usually extends upstream, downstream, and lateral from the project area. Impacts
result primarily from disruptions of hydrologic regimes. The increased efficiency with which a
cleared, wider channel drains its watershed causes floodplain dewatering. With dewatering,
wetland and floodplain vegetation can be expected to shift slowly in species composition from
flood-tolerant, hydric plants to flood-intolerant, mesic plant species (Maki et al. 1980, Simpson
et al. 1982). A reduction in biomass production of floodplain vegetation can also be expected
(Simpson et al. 1982). With such changes in vegetation, changes in the wildlife habitat value of
14
an area normally follow. A less productive, mesic environment probably would provide lower
quality wildlife habitat than riparian and floodplain forests with normal hydroperiods.
Stream bank clearing and channelization also may cause adverse impacts on aquatic resources
downstream of the project area. The impacts of stream bed sedimentation described above may
be particularly severe immediately downstream of the channelized section. The unaltered stream
bed with a natural, sinuous course has areas of low velocity flows where the heavy sediment
loads acquired upstream could settle out, accumulate over time, and ultimately smother existing,
benthic communities.
Indirect adverse impacts to fish and wildlife resources also may occur as a result of land use
changes which normally follow successfully dewatered floodplains. The feasibility of floodplain
development would be enhanced by any reduction in the frequency, magnitude, or duration of
floods along Hominy Swamp. Rapid runoffs from developed land would exacerbate instream
erosion, sedimentation, and flood problems locally and downstream. Public and private interest
in further flood control measures could follow and eventually be used to justify more costly
proj ects.
Cumulative Impacts
Cumulative impacts of flood control projects are described best in terms of state, regional, and
national rates of alteration of riverine and palustrine forested wetlands. Nationwide,
approximately 70 percent of the original floodplain forest has been converted to other land uses
(Brinson et al. 1981). About 60 percent of this country's major stream segments have been
significantly altered by water resource or other cultural developments (Brinson et al. 1981).
In the southeastern United States, few areas of bottomland hardwoods have escaped the impact of
man (Wharton et al. 1982). From 1960-1975 southeastern bottomland hardwoods were
converted at the estimated rate of 432,000 acres per year for a net loss of 6.4 million acres, or 20
percent of the total bottomlands (Mitsch and Gosselink 1986). From the mid-1970s to the mid-
1980s, the average annual loss of wetlands in 10 southeastern states was 259,000 acres (Hefner et
al. 1994). During the decade ending in the mid-1980s, North Carolina stood out among all
southeastern states with an estimated loss of 1.2 million acres in palustrine forested and scrub-
shrub wetlands. While the average annual net loss for all combined wetland types decline for the
state compared to earlier periods, the rate at which freshwater forested wetlands were lost and
converted increased (Hefner et al 1994). The proposed project could add to those losses either
directly through the removal of riparian trees or indirectly through the encouragement of
additional floodplain development.
Summary of Impacts
The potential impacts associated with the proposed project could alter and somewhat degrade
fish and wildlife habitats both within the project area and downstream. The most significant
15
adverse impacts would be the loss of natural riparian vegetation, removal of natural substrate and
increased sedimentation during construction. If the proposed project is ineffective at flood
control, there is also a risk that additional work may be proposed which would adversely impact
fish and wildlife resources. Therefore, the Service believes that any project should be based on
the most recent knowledge of hydrology and stream geomorphology in order to decrease the
possibility for additional work.
FISH AND WILDLIFE CONSERVATION MEASURES
Fish and wildlife resources in the Hominy Swamp study area could benefit from conservation
measures incorporated into an effective flood control project. Fish and wildlife conservation
measures as specified in the Fish and Wildlife Coordination Act consist of "means and measures
that should be adopted to prevent the loss of or damage to such wildlife resources (mitigation), as
well as to provide concurrently for the development and improvement of such resources
(enhancement)." Mitigation, as defined by the Council on Environmental Quality and adopted
by the Service in its Mitigation Policy, includes:
avoiding the impact entirely by not taking a certain action or parts of an action;
2. minimizing impacts by limiting the degree or magnitude of the action and its
implementation;
rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
4. reducing or eliminating the impact over time by preservation and maintenance operations
during the life of the action; and
5. compensating for the impact by replacing or providing substitute resources or
environments.
These five actions should be viewed as the proper sequence for formulating conservation
measures.
Enhancement measures are those which result in a net increase in resource values under the with-
project condition compared to the without-project condition. For any given type, kind, or
category of resource being evaluated, all project-associated losses must first be compensated, i.e.,
fully replaced, before any enhancement of that given resource can occur.
Minimization of project length, alternating the working bank, and removal of all dredge spoil
will do much to mitigate project related impacts on fish and wildlife. However, additional
mitigative measures are possible.
16
The implementation of a comprehensive, stormwater management plan could minimize the need
to disturb the existing stream channel and minimize the risk for future alterations of the channel.
Leopold (1994, p. 121) states:
"... flood control in the United States should place much greater
emphasize on restriction of development of floodplains, floodproofing
of individual sites or local areas, an insurance program in which
premiums are proportional to risk, and planned utilization of
floodplains for peak flow reductions. Reliance on engineering
protection by levees and dams should be a much less prominent part of
flood-damage mitigation."
The urbanization of natural floodplains produce several conditions which increase the risk of
flooding (Leopold 1994, pp. 165-167). Uncontrolled development in the 100-year floodplain
removes natural water storage capacity. The creation of large areas of impervious surface (e.g.,
parking lots) increases water runoff time during storms and contributes to flooding. The
stormwater management plan should include, at least, three major elements. First, a prohibition
on filling or development within the 100-year floodplain or within 100 feet of a perennial stream
or within 50 feet of an intermittent stream. Second, there should be an analysis of retrofitting
areas of existing development with stormwater ponds in order to increase flood storage capacity.
Third, undeveloped areas along the stream, such as parks, should be considered as possible,
natural, short-term water storage areas, or off-line detention ponds.
Any effort to move water more rapidly out of the project area has the potential to lower water
tables within the watershed. If water tables are lowered, wetlands farthest from stream channels
could lose the necessary hydrology to support wetland plants. The overall impacts of such
alterations would be the loss of wetlands. The Corps should ensure that project does not result in
a net loss or degradation of wetlands.
The Service believes that modifications to the existing channel should be extremely limited.
While any widening of the existing channel would move more water during flood events, such
widening would also alter the width/depth ratio of the channel. Rosgen (1996a, p. 6-19) notes
that excessive sediment deposition is associated with increases in width/depth ratios, stream
slopes, and other factors of channel morphology. The author also notes (Rosgen 1996a, p. 8-33)
that:
"River works often create `over-width' channel or a design discharge
width which does not meet the dimension, pattern and profile
interrelations with the bankfull discharge. These over-width channels,
while having larger streamflow capacity, induce sediment deposition,
resulting in decreased velocity and the loss of channel capacity and
competence."
17
For the proposed project, the wider stream would have less velocity during periods of normal
flow. The lower velocity would reduce sediment carrying capacity and contribute to
sedimentation which would ultimately lower flow capacity. Similarly, any significant deepening
would also affect flow characteristics and sediment bearing capacity. The removal of channel
deposits should be limited to isolated areas of significant sediment accumulation.
The removal of bank vegetation has the potential to reduce the natural filtering functions of such
vegetation and contribute to bank erosion. Riparian vegetation also reduces warm weather water
temperatures by shading streams. The value of riparian vegetation has been recognized by North
Carolina through the enactment Rule NCAC 2B .0233 which became effective on October 1,
1996. These regulations, which are known as the Neuse River rules, establish strict limits on the
removal of existing, riparian vegetation in a zone (Zone 1) which extends landward for 30 feet on
all sides of a water body within the Neuse River watershed. Any activities that would result in
water quality standard violations or that disrupt the structural or functional integrity of the
riparian area are prohibited. Forest vegetation of any width that exists in Zone 1 on the effective
date of the rules must be preserved and maintained, except for clearly defined situations, such as
individual trees in danger of damaging dwellings of the stream channel [Item (3)(a)(iv)]. While
these rules were enacted after development of initial project plans, the Corps should incorporate
these rules into the project. In general, the Service believes that the removal of vegetation should
be limited to completely detached material in the channel and material directly contributing to
bank erosion.
The goal of eliminating the blockage of flood waters by the railroad causeway should be
designed to move flood water without altering flow characteristics during normal periods.
Present designs call for the additional of a second, 12-foot culvert adjacent to the single, existing
culvert. This project feature would essential double the stream width at this location; from
approximately 12 feet to 24 feet. This design would alter width/depth ratios in a manner similar
to that produced by dredging to increase width and depth. As noted above, this change may lead
directly to increased sedimentation during periods of normal flow and, in time, negate the desired
increased flow capacity. This problem may be minimized by positioning the additional water
conveyance structures in the causeway at levels appropriate to carry water during flood stage, but
not during normal flow. A prominent river hydrologist, states in his training course that the best
way to ensure the passage of flood waters through causeways is to position floodflow
conveyance structures above the stage for normal, baseline flows (David Rosgen, 1996b). Such a
design would eliminate sedimentation in the new flood water passageways during periods of
normal flow.
The idea for a higher elevation for flood water passageways is similar to the concept of
"floodways" outlined by Hewlett (1982, p. 159). These floodways are alternate channels which
are designed to carry only exceptional flood waters. They are intended to be dry during non-
flood periods. These channels are effective, relatively cheap, and do not preclude other uses of
the land during normal flow periods.
18
Stream bed and bank disturbance by construction of the proposed project may itself cause a
significant increase in the sediment load in the project area and downstream. Every opportunity
should be taken to minimize these problems and to prevent the project from increasing erosion
and sedimentation problems over the long term. One method would be to limit the area of
construction work under way at any one time.
Construction measures which should be considered include the use of sediment traps. Upstream
traps could offset sediment problems caused by the project and improve the aquatic habitat
recovery potential. Downstream traps could protect downstream areas from increased
sedimentation problems resulting from the project construction and from long-term increases in
sediment flushed from the project area. Such controls could result in significantly more stable
aquatic habitats with benefits to fish and aquatic and semiaquatic wildlife.
Riparian revegetation may be the most significant opportunity to rectify impacts. Trees planted
on the stream banks would provide wildlife habitat and valuable shading of the stream. Mast-
producing, hardwood trees spaced widely along stream banks would shade the stream and help
stabilize the banks without causing significant impediments to water flow in the channel.
The habitat benefits of stream side area will be influenced by any landscape plan. In areas not
designated for public use, the benefits of planting herbs and shrub to wildlife will generally be
proportional to the height and density of the vegetation. Birds, small mammals, reptiles, and
amphibians will find more habitable if the riparian areas are mowed less frequently than twice-a-
year. Spring mowing would eliminate many wildlife breeding and nesting opportunities. Fall
mowing would destroy important cover and foraging habitat for overwintering wildlife. A
single, midsummer mowing every other year would greatly increase wildlife value of the areas
without significant impairment of the channel's drainage capacity.
RECOMMENDATIONS
The Service recommends that the following fish and wildlife conservation measures be
incorporated into Hominy Swamp flood control project:
1. The proposed project, by itself, would not provide a long-term, effective solution to
flooding along Hominy Swamp in the City of Wilson. Therefore, the Corps should
integrate any construction along the reach under consideration with a comprehensive
flood control program which includes: (1) limitations on development within the 100-
year floodplain; (2) the creation of stormwater retention ponds within existing
development; (3) the retrofitting of large areas of impervious surface to increase water
storage capacity; and, (4) the use of open areas, such as parks along Hominy Swamp, to
recreate floodplains, especially forested wetlands. While the Corps may not have the
authority to require the implementation of a flood control program, the final
environmental documentation should clearly outline the procedures necessary in achieve
effective, long-term flood control.
19
2. The Corps should ensure that the project does not result in adverse impacts to wetlands
due to the loss of hydrology associated with a lowering of water tables following efforts
to expedite flood flows.
3. Any in-channel modifications from the CSX railroad spur to Goldsboro Street (the
northern area of the proposed project) should be limited to the removal of isolated areas
of significant, in-channel sediment accumulations. Since any channel widening would
only reduce the sediment carrying capacity of the stream during baseflow conditions and
lead to increased sediment deposition, there should be no removal of material to widen
the existing channel.
4. In the southern part of the project area (CSX railroad spur to Blackcreek Road) the
removal of completely detached material is acceptable. However, the removal of any
plant material, either living or dead, which is attached to the bank or stream channel
(snagging) must comply with current regulations of the North Carolina Division of Water
Quality which provides special buffer rules for the Neuse River Watershed. All debris
removed from the project area should be transported to an approved upland site for
disposal.
5. Flow blockage at the railroad causeway should not be addressed with the proposed
addition of a second, 12-foot culvert. Efficient movement of flood water should be
achieved by one, or preferably more, new water conveyance structures at elevations
corresponding to flood stage. In order to minimize excessive sedimentation during period
of baseflow, the new conveyance structures should be at an elevation where they would
remain dry during baseflow periods.
6. In order to minimize erosion during construction, any work along the banks should be
conducted in stages. Each bank segment should be stabilized prior to initiating
construction on the adjacent segment. All spoil removed from the project area should be
transported to an approved, upland site for disposal.
7. To protect downstream aquatic habitats from sedimentation problems caused by project
construction, the proposed sediment trap to be created downstream of the project should
be maintained by cleaning during construction and for a specified period of time
thereafter to allow the banks to be stabilized with vegetation. Cleaning should be
undertaken whenever the trap becomes half full. This cleaning would insure that sudden
periods, of heavy rain would not cause the trap to overflow.
8. All areas cleared for construction should be landscaped in order to provide maximum
wildlife habitat and stream shading. Mast-producing, hardwood trees, such as oaks
(Quercus spp.) and hickories (Carya spp.), spaced widely along this stream bank would
shade the stream and help stabilize the banks without causing significant impediments to
water flow in the channel. The Corps should work with the local sponsor to develop a
20
maintenance program which enhances wildlife habitat. One beneficial aspect of such a
plan would be to schedule the mowing of herbaceous vegetation on bank areas at a
minimum interval of once during the midsummer every two years.
The full incorporation of these measure would not only minimize harm to fish and wildlife
resources, but would also greatly enhance these resources within the project area.
SUMMARY OF FINDINGS AND SERVICE POSITION
Coastal plain streams and the associated woodlands (minor alluvial floodplains), such as the
project area at Hominy Swamp, may serve as important fish and wildlife habitat., Habitats in and
adjacent to Hominy Swamp include the stream itself and naturally vegetated riparian areas. In
the undisturbed state, these areas provide habitat for a variety of fish and wildlife species.
However, fish and wildlife habitat has been degraded by and lost to previous stream
channelization and urban development. At the present time both aquatic and terrestrial habitats
in the project area are below optimum quality, and significant opportunities exist for
enhancement. The stream carries a sediment load eroded from construction sites, agricultural
activities, and other land disturbing activities. The stream is also adversely affected by urban
stormwater runoff, which physically and chemically stresses the instream biota. While naturally
vegetated riparian and floodplain areas are fragmented into small habitat patches by urban
development, these patches still provide valuable wildlife habitat.
Future human population development is likely to exacerbate aquatic and wetland habitat
degradation and loss unless comprehensive plans are implemented for natural resource
conservation, restoration, and enhancement. The Service believes that North Carolina's Neuse
River Rules are a positive step for improving water quality in the watershed, and that the
proposed project should comply with these rules. Furthermore, the development of a stormwater
management plan for the City of Wilson which restricts development in the floodplains of
Hominy Swamp would also benefit fish and wildlife resources. The long-term goal of
preventing flood damage is strongly supported by the Service, but the significant modification of
existing waterways without meaningful control of the underlying factors contributing to flooding
will not be successful.
In addition to the long-term benefits to be derived from comprehensive planning to minimize
flood damage, specific project modifications would benefit fish and wildlife resources in the
project area. The Service believes that the potential adverse effects of the proposed project can
be significantly reduced by implementation of the recommendations for fish and wildlife
conservation described in this report. Details for the implementation of the recommended
measures should be coordinated among representatives of the Corps, the City of Wilson, the
North Carolina Wildlife Resources Commission, the North Carolina Division of Water Quality,
and the Service.
21
LITERATURE CITED
Brinson, M.M., B.L. Swift, R.C. Plantico, and J.S. Barclay. 1981. Riparian ecosystems: their
ecology and status. U.S. Fish and Wildlife Service, Office of Biological Services,
Washington, D.C. FWS/OBS-81/17. 155 pp.
Hefner, J. M., B. O. Wilen, T. E. Dahl, and W. E. Frayer. 1994. Southeastern Wetlands; Status
and Trends, Mid-1970's to Mid-1980's. U. S. Department of the Interior, Fish and
Wildlife Service, Atlanta, GA. 33 pp.
Hewlett, J. D. 1982. Principles of Forest Hydrology. The University of Georgia Press. Athens,
GA. 183 pp.
Hodges, J. D. 1998. Minor alluvial floodplains. pp. 325-341. in M. G. Messina and W. H.
Conner (eds.) Southern Forested Wetlands. Lewis Publishers. Boca Raton, FL. 616 pp.
Hoover, J. J. and K. J. Killgore. 1998. Fish communities. pp. 237-260. in M. G. Messina and
W. H. Conner (eds.) Southern Forested Wetlands. Lewis Publishers. Boca Raton, FL.
616 pp.
Keunzler, E.J., P.J. Mulholland, L.A. Ruley, R.P. Sniffen. 1977. Water quality in North Carolina
coastal plain streams and effects of channelization. Water Resources Institute of the
University of North Carolina, North Carolina State University, Raleigh, NC. 160 pp.
Leedy, D.L., M. Maestro and T.M. Franklin. 1978. Planning for wildlife in cities and suburbs.
U.S. Fish and Wildlife Service. FWS/OBS-77/66. 64 pp.
T.M. Franklin and M. Maestro. 1981. Planning for urban fishing and waterfront
recreation. U.S. Fish and Wildlife Service. FWS/OBS-80/35. 108 pp.
Leopold, L. B. 1994. A View of the River. Harvard University Press. Cambridge, MA. xi +
298 pp.
Maki, T.E., A.J. Weber, D.W. Hazel, S.C. Hunter, B.T. Hyberg, D. M. Flinchum, J.P. Lollis, J.B.
Rognstad, and J.D. Gregory. 1980. Effects of stream channelization on bottomland and
swamp forest ecosystems. Water Resources Institute of the University of North Carolina,
North Carolina State University, Raleigh, NC. 135 pp.
Marzolf, G.R. 1978. The potential effects of clearing and snagging on stream ecosystems. U.S.
Fish and Wildlife Service, Office of Biological Services, Washington, D.C. FWS/OBS-
78/14. 31 pp.
22
Mitsch, W. J. and J. G. Gosselink. 1986. Wetlands. Van Nostrand Reinhold. New York, NY.
539 pp.
Potter, E. F., J. F. Parnell, and R. P. Teulings. 1980. Birds of the Carolinas. The University of
North Carolina Press. Chapel Hill, NC. 408 pp.
Radford, A.E., H.E. Ahles and C.R. Bell. 1968. Manual of the vascular flora of the Carolinas.
University of the North Carolina Press, Chapel Hill, NC. 1183 pp.
Rohde, F. C., R. G. Arndt, D. G. Linquist, and J. F: Parnell. 1994. Freshwater Fishes of the
Carolinas, Virginia, Maryland, and Delaware. The University of North Carolina Press.
Chapel Hill, NC. 222 pp.
Rosgen, D. L. 1996a. Applied River Morphology. Wildland Hydrology. Pagosa Springs, CO.
1996b. Lecture for Applied Fluvial Geomorphology class. Oxford, AL.
Simpson, P.W., J.A. Newman, M.S. Keirn, R.M. Matter, P.A.Guthrie. 1982 Manual of stream
channelization impacts on fish and wildlife. U.S. Fish and Wildlife Service, Office of
Biological Services, Washington, D.C. FWS/OBS-82/24. 155 pp.
Stanturf, J. A. and S. H. Schoenholtz. 1998. Soils and Landforms. pp. 123-147. in M. G.
Messina and W. H. Conner (eds.) Southern Forested Wetlands. Lewis Publishers. Boca
Raton, FL. 616 pp.
U. S. Army Corps of Engineers. 1997. Hominy Swamp, City of Wilson, North Carolina.
Detailed Project Report and Environmental Assessment on flood Damage Reduction.
Wilmington District, Wilmington, NC. 26pp. + Appendices A-F.
Webster, W. D., J. F. Parnell, and W. C. Biggs. 1985. Mammals of the Carolinas, Virginia, and
Maryland. The University of North Carolina Press. Chapel Hill, NC. 255 pp.
Wharton, C. H., W. M. Kitchens, E. C. Pendleton, and T. W. Sipe. 1982. The ecology of
bottomland hardwood swamps of the southeast: a community profile. U. S. Fish and
Wildlife Service. Biological Services Program. FWS/OBS-81/37. 133 pp.
Wigley, T. B. and R. A. Lancia. 1998. Wildlife communities. pp. 205-236. in M. G. Messina
and W. H. Conner (eds.) Southern Forested Wetlands. Lewis Publishers. Boca Raton,
FL. 616 pp.
23
r
r

Division of Water Quality
February 17, 1998
Memorandum
To: File
From: Eric Galamb
Subject: Corps of Engineers Study of Flood Damage Reduction at Hominy Swamp
Wilson County
Major Events
1. October 1964 flood - approximately 20-year event resulting in $55,000 in damages
2. COE releases EA in 1997
3. DWQ, WRC and USFWS meet COE on-site January 1998. COE states in meeting that they cannot increase the
downstream hydrograph. DWQ investigating this - law or policy?
Issues Discussed in EA
1. The middle watershed is urbanized, the lower is mostly rural and the upper watershed is undergoing rapid transition from
farmland and forest to residential and commercial use
2. Flood damages begin with the 4-year flood
3. 80% of flood damages occur between Black Creek Road and Tarboro Street (annual damages $1.4 M)
4. Flooding problem primarily due to CSX railroad causeway restricting flow. Additional upstream impervious
surfaces acerbate problem
5. COE studied structural (upstream dam, dikes or levees, culvert improvement, channel widening and deepening,
and clearing and snagging) and non-structural (floodproofing, structure elevation, flood plain evacuation and flood
warning system) alternatives
6. All plans considered clearing and snagging, channel widening and deepening, and culvert addition with variation
in channel width resulting in differing alternatives
7. COE projects flood reduction of 46% with proposed improvements
8. Project cost estimated to be $2.4 M
Issues Important to DWQ
1. Known upstream flooding problem at Kincaid Street (investigated and will be addressed by Wilson), therefore
COE should account for this additional water downstream
2. Additional culvert under railroad is O.K. but should be designed to be dry in normal flow to maintain proper width
to depth ratio of channel. Otherwise deleterious effects will be bank erosion and sediment deposition
3. Neuse buffer rules
• Clearing (the removal of obstructions) would be acceptable
• Snagging (the removal of a tree or a part of the tree that protrudes above the surface in the body of the water)
may not be acceptable unless threatening stream channel
• Channel widening violates rules and would remove existing riparian vegetation
4. DWQ would like COE to study the following alternatives that could singularly or in combination reduce the
hydrograph
• Increasing downstream flooding in wooded swamp below railroad causeway
• Retrofit stormwater ponds in upper watershed
• Create off-line detention ponds
• Restore or create wetlands in the watershed
• Instream dams (watershed must be less than 400 acres)
5. DWQ can require COE to study these alternatives by either EIS or alternatives analysis in 401. DWQ staff prefers an
EIS since the document is meant to be the decision making instrument. 401 application states that project has
construction in 2002
COE is proposing structural modifications to address flooding problem without changes in land use. Land use practices with
extensive pavement without design to alleviate these impacts to channels cannot be mitigated by structural additions or
modifications to stream channels (Stream System Technology Center).
AS PROPOSED DWQ WOULD FIND PROJECT IN VIOLATION OF WATER QUALITY RULES AND THEREFORE
WE WOULD RECOMMEND DENIAL OF THE 401 CERTIFICATION
4? NC DWQ WO ENVSCI Fax:[phone]
State' of North Carolina
Department of EnuIiroriment,
Health and Natural' Resources
Division-of Water Quality
James B. Hunt, Jr.; Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr,, P.E., Director
i '
Date FEB 1.7. i,
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PHONE;
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An Equal 01 p1 tunny Afltrmnlive Ar',finn Employer
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Division of Wi
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Raleigh, N.C.
F'AX,(919) 73;
Feb 17 '98 8:44 P.01/02
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SECTION
Environmental SCIGM;8,9; Branch. 44GI reedy Crook Road
1'e!e hon 9 Raleigh, Noah Carolina 27607
FAX # [phone]
60% re40ed OV. poet c»nsumer paper

4 4 ...N
« ?? NC DWQ WQ ENVSCI Fax:[phone] Feb 17 '98 8:44 P.02/02
Division of Water Quality
February 17, 1999
Monwaudum
TO; File
From: Eric G.damb
Subject; Corps 9f En'ginccrs Study Of-Flood ' Darjtagc RcducUon at Hominy Swamp
Wilson cWtIty
Major Event:
1. Octebcr 1,964 tload = agprcvtimatcly 24-guar event wwulting in $55,ooD in daamges
2. COE releases F,g•in 1997
3. DWQ, VMC and USFWS mcot CQE on•site, January 1998, COE states in meeting that they cannot inc eaw the
dnwnstreaun hydiograph. l6WQ, investigating this -law policy?
Issues Diav;uxed in FA
1. 'Ilia middle watersha ib urbanized, ehelowa' W taostiy.turAl Aid the upper waterilml Is undergnine, rapid tvansiiino fmtte
farmland andioretlt to ripidentlal.&nB.eamtneiciatuse
2. Flood daro.4gys begin with the: 4-year, flood
3. 0% of flwd damages: occur between..$i'ack Cheek Road and Tarboro Street (anneal damages $1.4 M)
4. blooding probleiii ptimarily'due to CS•X railroad vauseway restricting flow. • Additional upstream impervious
surfaces acerbate problem
:5, COE studied auvyt,ral (ups(ream dtim,. dikos im h:vices, culvert iatimumment,,chanuel widening and deepening,
and clearing and; snagging) and 0:64-atrilcturd (tlaodprI'm ttg, structure clevahon, flood plain evacuation and hood
warning system} alternatives
G. All plans considered clearing. and.snagg?ng, t:hauncl widening and deepening,. and culvert addition with Patiari0n
its. ahum6l width"resdItu,g in differing. altemativos
7. C(?E projects. flood reduotion of 46% with prdposed improveunents
8. Project Crrat ualitrtatcd W be $2.4 M
lrsuertnportant to DWQ)
1. Known upstreArn flooding problem at Kincaid Simet (investigated And will be:-addressed by Wilson), therefore
COE should account few this•additiortal'Water Oownstrc4m
2. Additional ctilvertunder railroad is O_K_ but should be designed to be dry in ncimal flow Ut Maintaw proper width
to depth ratio of cli noel. Otherwise deleterious effects will W bank erosion and sediment depositiun
I Neuse buffer rules
+ C10619: 0116 removal of. obstructions) would be acceptable
+ Snaggink ( 6lmmoval of a tree or a part pf the tree that protmdas above tho 6urfaoe iu the body of the w4 a)
may not be acceptable unless threatening sirea,n channel
• CLunnel wI'dct1i11g violidou rules anti-would remove existing riparim vegetation
4. DWQ would Re COE to study the following,?tornativea that could singularly, or in wmbination reduce the
bydrograpb
* Increasing dowastrratlr flooding in wooded, swamp below railroad causeway
+ Retrofit storinwaterponds in. upper waferAW
+ create off-line detention ponds
+ Restore or creafa wetlands in..thematdrihed
+ Inataeani d4na ,(watershed •myst be less than 400 acres)
5. i?WQ can require COE to atudi..i,hiveg'nitert v= ? y chhet EIti ar altciTAki!m attaly',sis in 4'(11. DWQ atatr prefers an
EIS since the'documont is meant to be the deiasion nlakfng instrument. 401 application states th4t prajcct 11M
construction in 2062-
COS is proposing structural tnc,difiestions to address flooding: problem without changes in land use. Land use prise ticsoa with
erttiaaive pavcmeltt Wiiliout tteeign tp Allevistc'the®e impacts to channels cannot be tnitig eted by straclural addition cur
modiiications to stream chuudu (Stream .Slretani Technology Center),
ASPR(V05EDDWQ•WOULD FINDPROJECT;INVIOLATIONQpWATER QUAI..tTYRULESAND THEREpORE
WE WOULD 1[IICOMM06 DENIAL OF THE 401 CERTIRCATION
???
t
• • 4,. .. , of North Carolina
Department of Environment LTW;WA
and Natural Resources 4 0
Division of Water Quality
James B. Hunt, Jr., Governor A A ?I
Wayne McDevitt, Secretary ED E N Ft
A. Preston Howard, Jr., P.E., Director
January 21, 1998
MEMORANDUM
To: Michelle Suverkrubbe
Through: John Dorney iz,
From: Eric Galambo,
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land Use in the watershed varies from rural farmland to highly
urbanized. The middle watershed is urbanized. The lower watershed is mostly rural and
the upper watershed is undergoing a rapid transition from farmland and forest to
residential and commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between Black Creek Road and Tarboro Street.
The COE studied structural and non-structural measures to address the flooding problem.
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofing were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore and
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8. Therefore, this was a very good day to observe the flooding problem.
Environmental Sciences Branch • 4401 Reedy Creek Road Raleigh, North Carolina 27607
Telephone [phone] FAX # [phone]
An Equoi OpporturOyAffirmattve Action Employer 50% recycled/t0% post consumer paper
",
According to the study, the main flooding problem is the blockage caused by the CSX
railroad causeway just upstream from US 301. Localized flooding occurs upstream of the
project also due to an inadequately sized culvert. The COE has no plans to address the
observed flooding problem upstream of the City Park adjacent to Ripley Road.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE regulations prohibit any increase in the hydrograph. DWQ does not oppose
the installation of an additional culvert. However, the culvert should be designed so that it
is in the dry during normal flow. Otherwise the stream morphology (width to depth ratio)
of the existing channel will be unbalanced resulting in bank erosion, sediment deposition
and other deleterious effects on water quality.
Due to the prohibition of increasing the_hydrograph, the COE investigated methods to
redface it. -
as a means to ameliorate the hydrograph. Hominy Swamp is in the Neuse River Basin.
Recently enacted rules (copy sent to Coleman Long and John Badin under separate cover)
prevent the removal of existing riparian forest vegetation in the Neuse basin with a few
narrow exceptions. The rules define forest vegetation as `The plants of an area which
grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
This includes mature and succession forests Ac wP ac en nvar a I- e
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street. Forest vegetation is lacking between Phillip Street and
Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Clearing (the removal of
obstructions) would be acceptable. Snagging (the removal of a tree or a part of the tree
that protrudes above the surface in the body of water) may not be acceptable. Rule
NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of individual trees which are in danger
of causing damage to dwellings, other structures or the stream channel. For the portion of
the project that we transversed, we located only one tree that was causing bank erosion
and therefore damage to the stream channel. The Neuse buffer rules would allow for this
individual tree to be removed but would not allow additional snagging.
Due to our rules, the project as proposed would not receive a 401 Water Quality
Certification. COE rules prohibit an increase in the downstream hydrograph. Therefore,
we must revisit acceptable alternatives to reduce the hydrograph and be in compliance
with all rules.
One cannot completely understand the processes that are shaping and influencing a stream
without data collection and interpretation. Dave Rosgen has developed a stream
classification system so that one can extrapolate data and predict process responses
(Rosgen, 1994). Most Federal and State agencies in NC are beginning to use this

classification system to solve similar problems with stream flow. The benefit of using
Rosgen's classifications is that one must thoroughly study and understand the stream's
current condition so that it can be matched to its hydrological potential
Whatever activities are undertaken by the COE, they will be short-lived without
substantial changes in land use development by the City of Wilson. Land use practices
with extensive pavement without design to alleviate these impacts to channels cannot be
mitigated by structural additions or modifications to stream channels (Stream System
Technology Center, 1985). The document states that 297 residences and 45 commercial
buildings are sited in the 100-year floodplain of Hominy Swamp. Last year the City issued
a building permit in the floodplain at Forest Hills Road and Little Hominy Swamp. These
encroachments remove storage capacity of the floodplain, which aggravates the
downstream flooding problem. Recently major commercial and residential construction
has occurred in the watershed. Plazas at the north side of the intersection of Forest Hills
Road and US 264 have been constructed without stormwater detention ponds. The
removal or elimination of land use activities that cause adverse impacts to riparian and
aquatic ecosystems are of the highest priority if restoration is to be accomplished (Stream
System Technology Center, 1985).
The COE indicated during our site visit that the City of Wilson is studying the flooding
problem at Kincaid Avenue. Again due to increased urban development, the culvert at
Kincaid Avenue and Hominy Swamp is probably undersized. The COE has separated this
flooding problem from their project. DWQ believes that these projects must be combined.
The flooding problem at Kincaid Avenue is significant. Therefore, this culvert will most
likely be replaced and the floodwaters backed up by the causeway will move into the
COE's project. Therefore, the COE should account for this additional water.
To ameliorate the flooding problems, alternatives in addition to the City of Wilson
adopting a stormwater management plan for the Hominy Swamp watershed must be
studied. DWQ proposed that the COE study areas where off-line detention ponds could
be constructed. One possible location for a pond would be at the Ridgewood Park off of
Phillip Street. There may be a need for several ponds in the watershed to completely solve
the flooding problem.
Another method to reduce the hydrograph may be to restore or create wetlands in the
watershed. Open land is present at Forest Hills Road and Little Hominy Swamp. Open
land is also present at the upper reaches of Big and Little Hominy Swamp. This work
could be done in conjunction with the Wetland Restoration Program. Mr. Ron Ferrell
should be contacted (919-733-5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration, off-line ponds, retrofitting impervious
areas with stormwater ponds, and upstream dams should be considered in a revised EA.

Please be aware that the Neuse rules have basinwide stormwater requirements (NCAC 2B
.0235) . The City of Wilson is required to submit a model local stormwater management
plan to control nutrients by August 1, 1999. The model plan must address nitrogen
reductions for e . ting and new development. All new development is to have no net
increase in peak?ow leaving the site from the predevelopment conditions. The plan must
also find locations for potential stormwater retrofits. These requirements should greatly
assist the COE in reducing the' "flooding problems in the Hominy Swamp watershed.
Due to the significant issues listed above, DWQ requests that an EIS be written for this
project. The project sponsor is reminded that the 401 Certification would be denied as
currently proposed for reasons described above. Questions regarding the 401
Certification should be directed to Eric Galamb (733-1786) in DWQ s Water Quality Non-
Discharge Branch.
References:
osgen,
10. "MM t
Stream System Technology Center. October 1985. Artificial Stream Restoration -
Money Well Spent or an Expensive Failure? Stream Notes.
Cc: Greg Thorpe, DWQ Planning
Owen Anderson, WRC
Ron Ferrell, WRP
-r
JAN 2 j 1998'1

Hominy Swamp Flood Control 2 January 25, 1998
City of Wilson, 98-E-0368
The project arcs is within an urbanized arcs of Wilson. Undeveloped portions of the
upper and middle watershed arc undergoing rapid development, which is causing a significant
increase in impervious swfuv= that exacerbates flooding problems. On our site visit we
observed what appeared to be recent filling of floodplain areas within this watershed.
The report states that the majority of flooding is caused by a hydraulic restriction at the
CSX railroad crossing. The most significant damage occurs upstream of the railroad crossing.
During our visit we also observed flooding of streets and yards within the floodplain of the creek
upstream of the proposed project. The flooding upstream in a residential subdivision appears to
be due to an undersized culvert at the Kincaid Avenue crossing of Hominy Swamp and the
location of streets immediately adjacent to the stream. However. this area is outside of the
proposed project and it is our understanding that the COE does not plan to consider the impacts
of future removal of this restriction on the downstream project.
The COE proposes to install an additional culvert at the CSX railroad crossing to
alleviate the upstream flooding. However, the additional culvert would increase the dowastreani
hydrograph by several feet. This is not permitted by COE regulations; therefore, the COE also
proposes to clear and snag the downstream section to Black Creek Road and remove some
sediments from this area and upstream of the CSC crossing to compensate for increasing of the
hydrograph.
The flooding problems and the solutions to flooding problems are closely related to issues
involving comprehensive stormwater management, riparian corridor protection and rules to
protect the Neuse River. Therefore, we believe that a more comprehensive review of this project
that includes development and flooding within the entire watershed is warranted. We have the
following recommendations and comments that need to be addressed in the expanded document.
1. As proposed the portion of the project that relates to removal of vegetation along the
stream banks appears to be contrary to rules established by the state to protect the Neuse
River. Therefore, we request that additional alternatives be examined to compensate for
the increase in hydrograph that do not require dredging and removal of woody vegetation.
Creating flood storage in parks and other vacant lots by removal of fill upstream of the
CSX crossing and restoration of wetlands in the watershed are alternatives that should be
evaluated. Alternatives need to be examined in light of new development and stormwater
management for the entire watershed.
2. We believe the problems in Wilson are directly attributable to poor siting of development
within a floodplain. This is somewhat understandable for older structures. However,
there appears to be continuing irresponsible development and filling of floodplains within
the Hominy Swamp Watershed. Any beuefts from the proposed project will be short
lived because the City of Wilson has not demonstrated effective protection of floodplains
and riparian corridors or management of stormwater. Additionally, we believe that the
project will allow for additional development in the watershed in floodplain areas
upstream of the project; and thus, is contrary to the intent of Executive Order 11988.
•717-JLO-70.17
NUWKI,,HI V Pr HLLJ LHKt ILL
Hominy Swtunp Flood Control 3 January 25,1998
City of Wilson, 98-E-0368
3. The additional culvert installed at the CSX crossing should not increase the width/dcpth
ratio of the stream. The additional culvert should be installed at an elevation so that it
will carry the flood flows and would remain dry during normal flows. This will reduce
the amount of maintenance that would be required due to sediment accumulation if
normal flows are spread over both culverts.
4. The increased drainage of upstream areas may have the potential to impact jurisdictional
wetlands by affecting wetland hydrology. The revised environmental document should
include a discussion of any adverse impacts the project would have on wetlands upstream
of the project and how any impacts to wetlands will be mitigated.
5. A comprehensive stormwater management plan that requires stonnwater detention ponds
and/or other best management practices (e.g., grass swales instead of curb and gutter)
should be required as part of this project for all development. A prohibition on filling or
6yelop-?-auMthln the 100 ear floodplain or within 100-feet of a perennial stream or
50-foot of an intermittent stream, wlnc ever is gr
project. The City of Wilson should consider retrofitting stormwater ponds within
existing developed areas to increase flood storage capacity. Properly designed ponds
could also provide some water quality benefits.
into this project. We look forward to
working with the City of Wilson, the COE and other agencies
and environmentally acceptable solution to this situation. If we can provide further assistance,
please contact our office at [phone].
cc; John Dorney, Division of Water Quality
Howard Hall, USFWS, Raleigh Office

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Division of Water Quality
February 17, 1998
Memorandum
To: File
From: Eric Galamb
Subject: Corps of Engineers Study of Flood Damage Reduction at Hominy Swamp
Wilson County
Major Events
1. October 1964 flood - approximately 20-year event resulting in $55,000 in damages
2. COE releases EA in 1997
3. DWQ, WRC and USFWS meet COE on-site January 1998. COE states in meeting that they cannot increase the
downstream hydrograph. DWQ investigating this - law or policy?
Issues Discussed in EA
1. The middle watershed is urbanized, the lower is mostly rural and the upper watershed is undergoing rapid transition from
farmland and forest to residential and commercial use
2. Flood damages begin with the 4-year flood
3. 80% of flood damages occur between Black Creek Road and Tarboro Street (annual damages $1.4 M)
4. Flooding problem primarily due to CSX railroad causeway restricting flow. Additional upstream impervious
surfaces acerbate problem
5. COE studied structural (upstream dam, dries or levees, culvert improvement, channel widening and deepening,
and clearing and snagging) and non-structural (floodproofing, structure elevation, flood plain evacuation and flood
warning system) alternatives
6. All plans considered clearing and snagging, channel widening and deepening, and culvert addition with variation
in channel width resulting in differing alternatives
7. COE projects flood reduction of 46% with proposed improvements
8. Project cost estimated to be $2.4 M
Issues Important to DWQ
1. Known upstream flooding problem at Kincaid Street (investigated and will be addressed by Wilson), therefore
COE should account for this additional wakr downstream
2. Additional culvert under railroad is O.K. but should be designed to be dry in normal flow to maintain proper width
to depth ratio of channel. Otherwise deleterious effects will be bank erosion and sediment deposition
3. Neuse buffer rules
• Clearing (the removal of obstructions) would be acceptable
• Snagging (the removal of a tree or a part of the tree that protrudes above the surface in the body of the water)
may not be acceptable unless threatening stream channel
• Channel widening violates rules and would remove existing riparian vegetation
4. DWQ would like COE to study the following alternatives that could singularly or in combination reduce the
hydrograph
• Increasing downstream flooding in wooded swamp below railroad causeway
• Retrofit stormwater ponds in upper watershed
• Create off-line detention ponds
• Restore or create wetlands in the watershed
• Instream dams (watershed must be less than 400 acres)
5. DWQ can require COE to study these alternatives by either EIS or altematives analysis in 401. DWQ staff prefers an
EIS since the document is meant to be the decision making instrument. 401 application states that project has
construction in 2002
COE is proposing structural modifications to address flooding problem without changes in land use. Land use practices with
extensive pavement without design to alleviate these impacts to channels cannot be mitigated by structural additions or
modifications to stream channels (Stream System Technology Center).
AS PROPOSED DWQ WOULD FIND PROJECT IN VIOLATION OF WATER QUALITY RULES AND THEREFORE
WE WOULD RECOMMEND DENIAL OF THE 401 CERTIFICATION
r . ?.
»e ,
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
eAk?b
FEB t .7
Date
FAX TO:
? P Vt v1i 5
FAX NUMBER:
FROM: ?-
PHONE:
I NO. OF PAGES INCLUDIN(
fltv S ko'c?eA
DO NOta W A ? -L
l
I D EHNR
Division of Water Quality
Environmental Sciences Branch
4401 Reedy Creek Road
Raleigh, N.C. 27607
FAX:[phone]
THIS SHEET: 7
VIC C4, i+
r ? '?
a 176?d reS fv S ?'rreT' ?`?
low
Environmental Sciences Branch 4401 Reedy Creek Road Raleigh, North Carolina 27607
Telephone [phone] FAX # [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/10% post consumer paper
., w

ov, 001"
U?o
State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality A&14
James B. Hunt, Jr., Governor AARJ?? Sk
Wayne McDevitt, Secretary E> E N FI
A. Preston Howard, Jr., P.E., Director
January 21, 1998
MEMORANDUM
To: Michelle Suverkrubbe
Through: John Dorney
From: Eric Galamb,,
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land Use in the watershed varies from rural farmland to highly
urbanized. The middle watershed is urbanized. The lower watershed is mostly rural and
the upper watershed is undergoing a rapid transition from farmland and forest to
residential and commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between Black Creek Road and Tarboro Street.
The COE studied structural and non-structural measures to address the flooding problem.
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofing were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore and
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8. Therefore, this was a very good day to observe the flooding problem.
Environmental Sciences Branch • 4401 Reedy Creek Road Raleigh, North Carolina 27607
Telephone [phone] FAX # [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/10% post consumer paper
'*
According to the study, the main flooding problem is the blockage caused by the CSX
railroad causeway just upstream from US 301. Localized flooding occurs upstream of the
project also due to an inadequately sized culvert. The COE has no plans to address the
observed flooding problem upstream of the City Park adjacent to Ripley Road.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE regulations prohibit any increase in the hydrograph. DWQ does not oppose
the installation of an additional culvert. However, the culvert should be designed so that it
is in the dry during normal flow. Otherwise the stream morphology (width to depth ratio)
of the existing channel will be unbalanced resulting in bank erosion, sediment deposition
and other deleterious effects on water quality.
as a means to
Due to the prohibition of increasing the hydrograph, the COE investigated methods to
reduce it. g aringand-snagging_coupled with channel widening was selected by the COE
Recently enacted rules (copy sent to Coleman Long and John Badin under separate cover)
prevent the removal of existing riparian forest vegetation in the Neuse basin with a few
narrow exceptions. The rules define forest vegetation as "The plants of an area which
grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
as well as cutover stands"
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street. Forest vegetation is lacking between Phillip Street and
Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Clearing (the removal of
obstructions) would be acceptable. Snagging (the removal of a tree or a part of the tree
that protrudes above the surface in the body of water) may not be acceptable. Rule
NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of individual trees which are in danger
of causing damage to dwellings, other structures or the stream channel. For the portion of
the project that we transversed, we located only one tree that was causing bank erosion
and therefore damage to the stream channel. The Neuse buffer rules would allow for this
individual tree to be removed but would not allow additional snagging.
Due to our rules, the project as proposed would not receive a 401 Water Quality
Certification. COE rules prohibit an increase in the downstream hydrograph. Therefore,
we must revisit acceptable alternatives to reduce the hydrograph and be in compliance
with all rules.
One cannot completely understand the processes that are shaping and influencing a stream
without data collection and interpretation. Dave Rosgen has developed a stream
classification system so that one can extrapolate data and predict process responses
(Rosgen, 1994). Most Federal and State agencies in NC are beginning to use this
? ' t
classification system to solve similar problems with stream flow. The benefit of using
Rosgen's classifications is that one must thoroughly study and understand the stream's
current condition so that it can be matched to its hydrological potential.
Whatever activities are undertaken by the COE, they will be short-lived without
substantial changes in land use development by the City of Wilson. Land use practices
with extensive pavement without design to alleviate these impacts to channels cannot be
mitigated by structural additions or modifications to stream channels (Stream System
Technology Center, 1985). The document states that 297 residences and 45 commercial
buildings are sited in the 100-year floodplain of Hominy Swamp. Last year the City issued
a building permit in the floodplain at Forest Hills Road and Little Hominy Swamp. These
encroachments remove storage capacity of the floodplain, which aggravates the
downstream flooding problem. Recently major commercial and residential construction
has occurred in the watershed. Plazas at the north side of the intersection of Forest Hills
Road and US 264 have been constructed without stormwater detention ponds. The
removal or elimination of land use activities that cause adverse impacts to riparian and
aquatic ecosystems are of the highest priority if restoration is to be accomplished (Stream
System Technology Center, 1985).
The COE indicated during our site visit that the City of Wilson is studying the flooding
problem at Kincaid Avenue. Again due to increased urban development, the culvert at
Kincaid Avenue and Hominy Swamp is probably undersized. The COE has separated this
flooding problem from their project. DWQ believes that these projects must be combined.
The flooding problem at Kincaid Avenue is significant. Therefore, this culvert will most
likely be replaced and the floodwaters backed up by the causeway will move into the
COE's project. Therefore, the COE should account for this additional water.
To ameliorate the flooding problems, alternatives in addition to the City of Wilson
adopting a stormwater management plan for the Hominy Swamp watershed must be
studied. DWQ proposed that the COE study areas where off-line detention ponds could
be constructed. One possible location for a pond would be at the Ridgewood Park off of
Phillip Street. There may be a need for several ponds in the watershed to completely solve
the flooding problem.
Another method to reduce the hydrograph may be to restore or create wetlands in the
watershed. Open land is present at Forest Hills Road and Little Hominy Swamp. Open
land is also present at the upper reaches of Big and Little Hominy Swamp. This work
could be done in conjunction with the Wetland Restoration Program. Mr. Ron Ferrell
should be contacted (919-733-5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration, off-line ponds, retrofitting impervious
areas with stormwater ponds, and upstream dams should be considered in a revised EA.
t' ' N
Please be aware that the Neuse rules have basinwide stormwater requirements (NCAC 2B
.0235). The City of Wilson is required to submit a model local stormwater management
plan to control nutrients by August 1, 1999. The model plan must address nitrogen
reductions for existing and new development. All new development is to have no net
increase in peak low leaving the site from the predevelopment conditions. The plan must
also find locations for potential stormwater retrofits. These requirements should greatly
assist the COE in reducing the flooding problems in the Hominy Swamp watershed.
Due to the significant issues listed above, DWQ requests that an EIS be written for this
project. The project sponsor is reminded that the 401 Certification would be denied as
currently proposed for reasons described above. Questions regardinf the 401
Certification should be directed to Eric Galamb (733-1786) in DWQ s Water Quality Non-
Discharge Branch.
References:
of-Natural Rivers. _ Catena (22) pp. 169-199.
Stream System Technology Center. October 1985. Artificial Stream Restoration -
Money Well Spent or an Expensive Failure? Stream Notes.
Cc: Greg Thorpe, DWQ Planning
Owen Anderson, WRC
-- coward Hall, USFWS

JAN 2 1 199&f
EMORANDUM
L• Env. Sciences Branch (WQ Lab)
O Trish MacPherson (end. sps)
O Kathy Herring (forest/ORW/HQW)
O Larry Ausley (ecosystems)
O Matt Mathews (toxicology)
O Jay Sauber (intensive survey)
4on-Discharge Branch (Archdale 9th)
O Kim Colson (Permitting)
* Wetlands (WQ Lab)
O John Dorney (Corps, 401)
O Cyndi Bell (DO'1)
' <Enc Galamb
ioint Source Branch (Archdale 9th)
0 Dave Goodrich (NPDES)
0 Bradley Bennett (Stormwater)
0 Tom Poe (Pretreatment) (Archdale 7th)
Reg./ Prg. Mgmt Coordination Branch
O Farrell Keough (Archdale 9th)
0 Brent McDonald (Archdale 12th)
* Regional Water Quality Supervisors
O Asheville O Mooresville O Washington
O Fayetteville O Raleigh O Wilmington
O Winston -Salem
Planning Branch (Archdale 6th)
O Alan Clark (basinwide planning)
O Boyd DeVane (classifications & standards)
O Beth McGee (management planning) . . .
O Ruth Swanek (modeling) (Archdale 9th)
O
O
M. Michelle Suverkrubbe, Regional / Program Management Coordination Branch
lied is a copy of the above document. subject to the requirements of the North Carolina
onmental Policy Act, you are being asked to review the document for potential significant impacts
environment, especially pertinent to your jurisdiction, level of expertise or permit authority. Please
the appropriate box below and return this form to me along with your written comments, if any, by
ite indicated. Gtr lid *?-/
SPONSIE DEADLINE:`
' t= NO COMMENT ? COMMENTS ATTACEJED
MIC:
IT .p
Y, # 7 rl7ate:
k you for your assistance. Suggestions for streamlining this process are greatly appreciated!
s:
Mn be reached at:
lone: [phone], ext. 567 fax: [phone] e-mail: [e-mail]
sAcircmemo - mac version
v M
w -
DETAILED PROJECT REPORT
AND
ENVIRONMENTAL ASSESSMENT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON,
NORTH CAROLINA
US Army Corps
of Engineers
Wilmington District
South Atlantic Division
r..
October 1997
< ,. ? ?
DETAILED PROJECT REPORT AND ENVIRONMENTAL ASSESSMENT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON, NORTH CAROLINA
SYLLABUS
The purpose of this study was to investigate the flood problem on Hominy
Swamp at Wilson, North Carolina, and develop plans for flood damage reduction.
This study was initiated in response to a request from the City of Wilson. The
study was conducted under authority of Section 205 of the 1948 Flood Control
Act, as amended.
Hominy Swamp, also known as Hominy Swamp Canal, is located in the Neuse
River basin in eastern North Carolina. The Recommended Plan of Improvement
consists of channel improvements over approximately 2.1 miles of Hominy Swamp.
These improvements include:
o Placement of a 12-foot-diameter culvert in a railroad fill. This
culvert will supplement an existing culvert, and will reduce ponding behind the
fill during flood events.
o widening approximately 1.2 miles of the Hominy Swamp channel to a bottom
width of 25 feet. Portions of the stream channel will also be deepened to
provide a uniform stream gradient.
o Clearing and snagging approximately 0.9 mile of Hominy Swamp. Clearing
and snagging will be conducted downstream from the channel reach to be widened.
Alternatives to the proposed action include different channel lengths and
widths. Among the available alternatives, the Recommended Plan maximizes net
economic benefits.
The estimated first cost of the recommended plan of improvement is
$2,401,000. With average annual costs estimated at $215,319 and expected
annual benefits estimated at $646,000, the project benefit-cost ratio is 3.0.
The majority of the benefits are for flood damage reduction to commercial
properties.
No significant environmental impacts will result from implementation of the
project plan. An Environmental Assessment is included with this report. The
Environmental Assessment includes a Section 404(b)(1) evaluation.
DETAILED PROJECT REPORT AND ENVIRONMENTAL ASSESSMENT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON, N.C.
Table of Contents
Item Page No.
SECTION I - INTRODUCTION
AUTHORITY AND BACKGROUND ..................................................... 1
SCOPE OF THE STUDY ........................................................... 1
STUDY PARTICIPANTS AND COORDINATION .......................................... 1
REPORT ORGANIZATION .......................................................... 2
EXISTING FEDERAL PROJECTS .................................................... 2
BASIN DESCRIPTION ............................................................ 2
DEVELOPMENT AND ECONOMY ...................................................... 2
SECTION II - PROBLEM IDENTIFICATION
THE FLOOD PROBLEM ............................................................ 4
POTENTIAL ECONOMIC BENEFITS .................................................. 5
ENVIRONMENTAL CONSIDERATIONS IN PROJECT PLANNING ............................. 5
SECTION III - PLAN FORMULATION
MEASURES CONSIDERED .......................................................... 6
NONSTRUCTURAL MEASURES ................................................. 6
STRUCTURAL MEASURES .................................................... 7
PLANS OF IMPROVEMENT CONSIDERED ............................................. 10
PROJECT REACH ......................................................... 10
COMMON PLAN FEATURES .................................................. 10
ALTERNATIVE PLANS ..................................................... 11
EVALUATION OF ALTERNATIVE PLANS ....................................... 11
BASIS FOR PLAN SELECTION .................................................... 12
DESIGNATION OF NATIONAL ECONOMIC DEVELOPMENT PLAN ........................... 12
SECTION IV - THE SELECTED PLAN
PLAN FEATURES ............................................................... 13
CULVERT PLACEMENT ..................................................... 13
CLEARING AND SNAGGING ................................................. 13
CHANNEL EXCAVATION .................................................... 13
SLOPE PROTECTION ...................................................... 15
LANDSCAPING PLAN ...................................................... 15
SEDIMENTATION CONTROL MEASURES ........................................ 15
PROJECT CONSTRUCTION ......................................................... 16
DISPOSAL AREAS ........................................................ 16
REAL ESTATE REQUIREMENTS .............................................. 16
RELOCATIONS ........................................................... 17
PROJECT MAINTENANCE ................................................... 17
`1
DETAILED PROJECT REPORT AND ENVIRONMENTAL ASSESSMENT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON, N.C.
Table of Contents--continued
Item
SECTION IV - THE SELECTED PLAN--continued
Page No.
PLAN ACCOMPLISHMENTS ............................................ 18
EXPECTED ANNUAL BENEFITS .................................................... 18
ECONOMIC COSTS .............................................................. 19
BENEFIT-COST RATIO .......................................................... 19
ENVIRONMENTAL IMPACTS ....................................................... 21
EFFECTS ON HAZARDOUS AND TOXIC WASTE POTENTIAL _-21
2C'tlrJVa7. Cr im • • . . . • •-• • • • • • • • • • . • . • • • • • . • • • • • • . . . • _
1MPA ON THE FLOOD PLAIN AND COMPLIANCE WITH EO 11988 ...................... 22
IMPACTS ON MANMADE RESOURCES ................................................ 22
PUBLIC VIEWS ................................................................ 22
VIEWS OF NON-FEDERAL SPONSOR .......................................... 22
VIEWS OF U.S. FISH AND WILDLIFE SERVICE ............................... 22
SECTION V - DIVISION OF PLAN RESPONSIBILITIES .............. 24
SECTION VI - CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS ................................................................. 25
RECOMMENDATIONS ............................................................. 25
ENVIRONMENTAL ASSESSMENT
(FOLLOWS PAGE 26)
List of Tables
Item
Page No.
1 Average Annual Food Damages ..................................... 4
2 Economic Data, Plans Considered ................................ it
3 Estimated Real Estate Costs, Selected Plan ..................... 17
4 Expected Annual Benefits, Selected Plan ........................ 18
5 Project First Costs ............................................ 20 -
6 Cost Sharing, Selected Plan .................................... 27
ii
DETAILED PROJECT REPORT AND ENVIRONMENTAL ASSESSMENT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON, N.C.
Table of Contents--continued
14
List of Ficrures
Figure No. Subiect Page No.
1 Basin Map ....................................................... 3
2 Photos of Study Area ............................................ 8
3 Plan of Improvement ............................................ 14
List of Appendixes
APPENDIX A - PERTINENT CORRESPONDENCE
APPENDIX B - REPORT BY US FISH AND WILDLIFE SERVICE
APPENDIX C - HYDROLOGY AND HYDRAULIC ANALYSIS
APPENDIX D - REAL ESTATE
APPENDIX E - ECONOMIC ANALYSIS
APPENDIX F - PROJECT COSTS
iii
DETAILED PROJECT REPORT
ON FLOOD DAMAGE REDUCTION
HOMINY SWAMP
CITY OF WILSON, NORTH CAROLINA
SECTION I - INTRODUCTION
This study was conducted to develop means of addressing the flooding
problem along Hominy Swamp at Wilson, North Carolina. Portions of Hominy
Swamp, also known as "Hominy Swamp Canal, 11 have been channelized by the City of
Wilson. However, silting, bank erosion, and vegetation growth have reduced the
stream capacity, and flooding remains a recurring problem. As discussed
herein, widenvng and clearing the Hominy Swamp channel would substantially
reduce flood damages along the stream, and implementation of a Federal project
for this purpose is recommended.
AUTHORITY AND BACKGROUND
This study was conducted under authority of Section 205 of the 1948 Flood
Control Act, as amended. The Hominy Swamp basin was studied previously as part
of a General Investigation Study of the Neuse River basin by the Wilmington
District. This study, concluded in 1991, indicated that flood damage reduction
measures for Hominy Swamp were potentially feasible, and recommended further
studies under the continuing authority program. By letter dated September 9,
1991, the City of Wilson requested that further studies be conducted, and
indicated its intent to act as non-Federal sponsor for the Hominy Swamp project
(see page A-1, appendix A, for correspondence).
SCOPE OF THE STUDY
This study included the flood plain of Hominy Swamp. The primary study
focus was in the Wilson urban area, where the majority of the flood damages
along Hominy Swamp occur.
STUDY PARTICIPANTS AND COORDINATION
Data concerning flooding in Wilson were provided by City officials and
local residents. The City of Wilson also contributed one half of the study
costs. The U.S. Fish and Wildlife Service participated in this study, and
prepared the Fish and Wildlife Coordination Act Report included as appendix B
of this report.
1
REPORT ORGANIZATION
This document includes the Detailed Project Report and Environmental
Assessment for Flood Damage Reduction, Hominy Swamp. The detailed project
report presents the results of planning studies conducted to address the flood
problem along this stream. The environmental assessment presents data required
by the National Environmental Policy Act of 1969 and other Federal laws and
executive orders pertaining to environmental quality.
EXISTING FEDERAL PROJECTS
There is no existing Federal project on Hominy Swamp. However, portions
of Hominy Swamp have been channelized by the City of Wilson.
BASIN DESCRIPTION
- - - - - -- -Hominy--Swamp - is located -in-the coastal -plain of North- Carolina - and J q, a -
- tributary of Contentnea Creek. Hominy Swamp has its headwaters northwest of
Wilson and drains approximately 15.7 square miles (see figure 1, following
page). The stream stations shown on figure 1 are in feet above the mouth of
Hominy Swamp at Contentnea Creek.
The topography of Hominy Swamp is typical of streams in the Coastal Plain
region of North Carolina. The lower portion of the channel is swampy, with a
wide flat channel and low banks. As the channel progresses upstream it becomes
the downstream end Hominy Swamp to lightly wooded and grassy further upstream
in the Wilson urban area. The channel bottom is about 4 feet wide at Raleigh
Road and widens to about 20 feet at the Wilson Wastewater Treatment Plant (see
figure 1 for locations).
DEVELOPMENT AND ECONOMY
The City of Wilson had a 1990 population of 36,910. The principal
industries are tire and rubber, metalworking, textiles, tobacco, and
pharmaceutical. Wilson is a regional banking, trade and services center for
surrounding rural areas, and is the county seat of Wilson County. Interstate
95 connects the city to the interstate highway system.
Land use in the Hominy Swamp watershed varies from rural farmland to
highly developed. The lower portion of the flood plain, near Contentnea Creek,
is swampy and largely undeveloped. Land use in the middle reaches of the
stream, through the center of Wilson, is mainly commercial and industrial with
some high density residential development. The upper basin is undergoing a
transition from farmland and forest to residential use.
2

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HOMINY SWAMP
CITY OF WILSON, NORTH CAROLINA
BASIN MAP
c? U.S. ARMY ENGINEER DISTRICT
WILMINGTON, N.C.
3
Figure 1
SECTION II - PROBLEM IDENTIFICATION
The purpose of this report section is to analyze the flood problem along
Hominy Swamp, and to estimate the potential economic benefits which can be
realized by reducing flood damages in this area.
THE FLOOD PROBLEM
Flood damages were evaluated for the entire Hominy Swamp basin. Flood
damages in the developed portion of the flood plain begin at about the 4-year
exceedence interval (flood having a probability of being exceeded once in a 4-
year period). There are 297 homes and 45 commercial buildings in the 100-year
flood plain. .
Flood damages in the Hominy Swamp flood plain were computed for the
categories shown in table 1, below. Average annual damages were computed using
Wilmington District computer programs which correlate stage damage and
frequency data and compute average annual damages for each property along the
stream. Total average annual damages are estimated at $1,393,000. Eighty
percent of the flood damage occurs between Black Creek Road and Tarboro Street
(see figure 1). The flood plain downstream from the Wilson Wastewater
Treatment Plant (Station 150+00) is undeveloped, and flood damages are minimal.
The expected annual flood damages shown in table 1 were computed for existing
conditions only; no future increases in flood damages are anticipated.
TABLE 1
Average Annual Flood Damages, Existing Conditions
Flood
Damage
Category Damageable
Property Value Average
Annual
Damages Percent
of Total
Residential $ 25,260,000 $ 391,000 28
Commercial 12,699,000 137,000 10
Industrial 73,980,000 710,000 51
Utilities 5,203,000 47,000 3
Transportation 4,380,000 32,000 2
Emergency Costs 76,000 6
Total $125,522,000 $1,393,000 100
0v
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4
POTENTIAL ECON041C BENEFITS
As showm on the preceding page, expected annual damages in the Hominy
Swamp basin are estimated at $1,393,000. This figure is significant since
average annual benefits for any Federal plan of improvement must exceed average
annual costs. Thus, this figure establishes the "upper limit" for costs of
Federal improvements in the study area. In addition to producing net economic
benefits, any plan of improvement to be recommended for Federal implementation
must also be environmentally acceptable. Environmental considerations in
project planning are discussed below.
ENVIRONMENTAL CONSIDERATIONS IN PROJECT PLANNING
As reported in the attached environmental assessment, the study area was
examined for the presence of significant resources, and the qualities of these
resources were investigated. Also, the area was examined for potential
hazardous or toxic waste sites. No hazardous or toxic waste sites were
identified which would be affected by the improvements_ considered in this
Through the Wilson urban area, previous channelization and clearing of
vegetation, along with intense, rapid urban and agricultural runoff, create
poor quality aquatic habitat conditions and low species diversity over most of
Hominy Swamp in the Wilson urban area. The streambed in the urban reaches of
Hominy Swamp is comprised of unstable and unconsolidated sand and silt and is
generally unvegetated.
In the downstream portion of Hominy Swamp, near-Contentnea Creek, a
Stream rrom the wiison
Wastewater Treatment Plant, includes high quality botttomland hardwood and
wetland habitat. Photographs of the study area are shown on figure 2, pages 8
and 9.
5
SECTION III - PLAN FORMULATION
Plan formulation in this study consisted of evaluating various means of
reducing flood damages along Hominy Swamp, and identifying the best plan of
improvement. This report section includes (1) a discussion of general
approaches, or management measures considered; (2) development of alternative
plans; and (3) the rationale for plan selection.
MEASURES CONSIDERED
Two categories of measures, referred to as "structural" and
"nonstructural" measures, were considered to address the Hominy Swamp flood
problem. Measures in each category are discussed below.
NONSTRUCTURAL MEASURES
"Nonstructural measures" include measures which reduce the damageability
of structures and contents in the flood plain. These measures do not
significantly alter the depth or extent of flooding. Nonstructural measures
considered include floodproofing, structure elevation, removal of structures
from the flood plain, and flood warning systems. Each of these measures is
discussed below.
Floodproofing - No concentrated damage center was identified where
floodproofing might be economically feasible. Floodproofing of the large
number of structures along Hominy Swamp ( `q resddencos -and 45.commergialb.
itniidings,in'the 100-year,.<flood, plain) ;Was fudged to be more costly than-'
channel improvement (discussed on page 7).
Structure Elevation - This measure was likewise not considered in detail,
due to the number of structures affected by flood damages along Hominy Swamp.
Flood Plain Evacuation - Evacuation of the flood plain of Hominy Swamp
was not considered a practicable measure. Costs and social impacts associated
with this measure were considered to be prohibitive.
Flood Warning System - A flood warning system would consist of a data
collection system, including river gages, and a communication system to warn of
an approaching flood. While this measure is effective in some locations, it
was not considered appropriate for the Hominy Swamp basin, due to the small
size of the basin and the short warning time which would be available.
6
STRUCTURAL MEASURES
Possible structural measures to address the flood problem on Hominy Swamp
include channel improvement, dikes or levees, and an upstream dam. Each of
these measures-is discussed below.
Upstream Dam - Upstream dams reduce flood damages by retaining
floodwaters for controlled release. This measure was not considered _
practicable for Hominy Swamp due to the lack of a suitable site for dam
construction. A reservoir upstream of the developed area would not control a
sufficient portion of the drainage area to be an effective flood control
measure. `
Dikes or Levees - Dikes or levees would prevent the encroachment of
floodwaters into developed areas. However, these measures require adequate
right of way. Due to the proximity of roads, buildings, and utilities to
Hominy Swamp, dikes and levees were not considered practicable and were not
evaluated in detail.
_ __-Culvert-Improvement--- -Hominy--Swam - asses-
aliftream-UT US ig way (Station 248+90). The existing culvert is not
adequate to pass flood flows, creating ponding upstream of the fill during
flood events. Placement of an additional culvert was evaluated in conjunction
with the channel improvements described below. (Note: two railroad crossings
occur in the study area; the first is the Norfolk - Southern (CSX) mainline
crossing referred to above; the second crossing is a CSX spur line trestle
downstream from the mainline fill at Station 227+50; both crossings are shown
on figure 1, page 3, and in the photographs shown in figure 2, pages 8 and 9).
ing - is measure would increase the capacity
of the stream to convey floodwaters and reduce flood stages. Widening would be
conducted throughout the improved reach of stream, while deepening would be
limited to the extent necessary to provide a uniform stream gradient. This
measure was considered for the Wilson urban area, where flood damages on Hominy
Swamp are most severe. '
Clearing and Snagging - Clearing and snagging consists of removing
debris from the stream and cutting and removal of saplings and undergrowth
which impede flow. Like channel excavation, this measure would increase
channel capacity. While the increase in channel capacity is generally less
than that achieved with channel excavation, clearing and snagging is much less
expensive. Therefore, this measure was considered for the downstream portion
of Hominy Swamp, where vegetation constricts stream flow and damages are not
sufficient to justify channel improvement.
7
FIGURE 2 - PHOTOGRAPHS OF PROJECT AREA. The photograph above
shows Hominy Swamp through the Wilson urban area. This portion of
the stream has previously been channelized, but silt and vegetation
growth have reduced its hydraulic capacity. In contrast, the
photograph below shows Hominy Swamp downstream from the Wilson
wastewater treatment plant, where a flood plain forest remains.
8

FIGURE 2 - PHOTOGRAPHS OF PROJECT AREA - CONTINUED. These
photographs show the two railroad crossings in the project area.
The photograph above shows the CSX spur line trestle (Station
227+50), looking downstream. Each plan of improvement considered,
discussed on the following page, includes clearing and snagging
downstream from this trestle to Black Creek Road, with channel
excavation upstream to Goldsboro Street. The photograph below
shows the culvert in the CSX mainline fill (Station 248+90). Each
plan of improvement considered includes placement of an additional
culvert at this location to improve flow conditions and reduce
ponding behind the fill.
9
PLANS OF IMPROVEMENT CONSIDERED
As discussed in the preceding report section, the flood damage reduction
measures identified for Hominy Swamp included channel excavation (widening and
deepening), clearing and snagging, and placement of an additional culvert in a
railroad fill. Development of alternative plans consisted primarily of
defining the reach where channel improvement would be practicable, and
selecting the optimum channel width. Each of these steps is discussed below.
PROJECT REACH
All plans of improvement considered in detail for Hominy Swamp consisted
of channel improvement (clearing and snagging or channel widening and
deepening) from Black Creek Road (Station 180+00) upstream to Goldsboro Street
(Station 294+70), a distance of approximately 2.1 miles. This reach of Hominy
Swamp was selected for detailed analysis since: (1) the reach downstream from
Black Creek Road is generally undeveloped, and flood damages are minimal; and
(2) channel improvement upstream from the Goldsboro Street bridge was
determined to be economically infeasible (costs exceed benefits). An
evaluation of.flood damages and channel improvements considered for the reach
of Hominy Swamp upstream from the Goldsboro Street bridge is presented on page
E-5, appendix E.
COMMON PLAN FEATURES
All plans considered for Hominy Swamp included the following features:
o Clearing and Snagging - Clearing and snagging was considered for the
downstream portion of the project reach, from the CSX spur line trestle
(Station 227+50) to Black Creek Road (Station 179+30), a distance of
approximately 0.9 mile. This reach of Hominy Swamp is bordered by heavy
vegetation, and flow is restricted by fallen limbs and leaning trees. There is
minimal development in this reach.
o Channel Widening and Deepening - Channel widening and deepening was
considered for the reach of Hominy Swamp from the CSX spur line trestle
(station 227+50) upstream to Goldsboro Street (Station 292+40), a distance of
1.2 miles. All widening alternatives considered for Hominy Swamp were based on
a trapezoidal channel with sideslopes of 1 horizontal to 1 vertical. Widening
would be conducted throughout the 1.2-mile reach, with deepening limited to
areas where silt accumulations restrict flow.
o Culvert Addition - Placement of an additional culvert at the CSX
mainline fill (Station 248+90) upstream of US Highway 301 was considered in all
plans.
10
ALTERNATIVE PLANS
Three plans of improvement were considered in detail for Hominy Swamp.
As described on the previous page, each of these plans included channel
improvements (clearing and snagging or channel deepening and widening) over a
reach of approximately 2.1 miles. The variable among the alternatives
considered was the width of channel excavation.
The term "channel width," as used herein, refers to the bottom width of
the constructed channel. For example, widening the existing channel to 25 feet
would require 10 feet of channel excavation if the.existing bottom width is 15
feet wide. Channel widths considered for Hominy Swamp were 25, 30, and 35
feet. While the wider channel would produce greater benefits, 'it would also
involve greater costs. Channel widths substantially greater than 35 feet would
involve prohibitive costs for excavation, real estate, -and relocations.
Channel widths less than 25 feet would not provide substantial flood damage
reduction benefits.
EVALUATION OF ALTERNATIVE PLANS
for ominy swamp are designated
the 25-foot, 30-foot, and 35-foot plans. Each plan contains the three common
elements described on the previous page. As noted above, the only variable
among the three plans is the bottom width of the channel excavation from the
CSX trestle up to Goldsboro Street. Selection of the optimum plan of
improvement was based on a comparison of benefits and costs, shown in table 2,
below.
TABLE 2
Economic Data, Plans Considered

Plan
First
Cost Average
Annual
Benefits Average
Annual
Costs
Net
Benefits Benefit-
Cost Ratio
25-ft. $2,401,000 $646,000 $215,000 $431,000 3.0
30-ft. $2,597,000 $662,000 $231,000 $431,000 2.9
35-ft. $2,793,000 $678,000 $247,000 $431;000 2.7
11
BASIS FOR PLAN SELECTION
As shown in table 2, net economic benefits, computed as average annual
benefits minus average annual costs, are equal for all three detailed plans
considered ($431,000). Since the 25-foot plan produces the same, or
approximately the same, net benefits as do the larger, more costly plans, this
plan is selected for implementation.
DESIGNATION OF THE NATIONAL ECONOMIC DEVELOPMENT PLAN
The Federal objective in water resources planning is to contribute to the
National Economic Development. The plan which produces the greatest net
benefits among- the available alternatives is referred to as the "National
Economic Development" (NED) Plan, and is usually recommended for
implementation. In the case of Hominy Swamp, the 25-foot plan referred to
above is designated the NED Plan, since net benefits for the detailed plans
considered are equal, and this is the least costly alternative.
12
SECTION IV - SELECTED PLAN OF IMPROVEMENT
The Selected Plan of Improvement consists of various channel improvements
over approximately 2.1 miles. Plan features are discussed below, following by
discussions of benefits and costs and environmental impacts.
PLAN FEATURES
The three principal plan features include placement of a second culvert
at the CSX mainline fill and channel improvement along approximately 2.1 miles
of Hominy Swamp (see figure 3 for locations). Other project features,
discussed below, include landscaping, slope protection, and sedimentation
control.
CULVERT PLACEMENT
A 12-foot diameter culvert will be installed through the fill under the
CSX main line (Station 248+90) to improve flow conditions. The culvert would
be assembled from steel liner plate as a tunnel is excavated through the fill.
Headcover above-the top of the culvert-will-be about °15 feet.
CLEARING AND SNAGGING
Clearing and snagging will be conducted along approximately 0.9 mile of
Hominy Swamp, from Black Creek Road upstream to the CSX railroad trestle.
Clearing and snagging will consist of removing debris and cutting saplings and
underbrush. Large trees will not be cut unless they are leaning and in danger
of falling into the channel.
The Hominy Swamp channel will be widened to a bottom width of 25 feet
from the CSX railroad trestle upstream to the Goldsboro Street Bridge, a
distance of 1.2 miles. The channel will be deepened by 1 to 1.5 feet over a
reach of approximately 300 feet. The reach to be deepened is from Ralston
Street, the street immediately north of the CSX spur trestle, downstream to
approximately 200 feet below the trestle. In other parts of the project reach,
minor areas of sediment accumulation will be removed. Side slopes will be 1
horizontal to 1 vertical. Approximately 37,000 cubic yards of earth will be
excavated for project construction.
Project construction will generally be limited to one bank, with the
working bank alternating from side to side. Excavation of both banks will be
necessary in transition areas where the channel improvement switches from one
bank to the other, and in areas where slopes need dressing for stability.
13
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BOTTOM TO 25 FEET
y CULVERT ADDITION STATIONO227+50
_ 1STATION 248+90 STATION 292+40
US 301
CLEAR AND SNAG
STATION 179+30
TO
STATION 227+50
179+30
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Fiaure 3
SLOPE PROTECTION
Slope stabilization will be accomplished by grassing over most of the
project reach. Generally, stream velocities are not erosive on Hominy Swamp
and riprap (stone slope protection) will not be required at most locations.
Riprap will be required immediately downstream of the railroad culvert
where velocities would otherwise result in erosion. Riprap will also be
required at the upstream terminus of the project at the Goldsboro Street Bridge
(see page C-11, appendix C).
LANDSCAPING PLAN
As discussed on page 13, channel widening will alternate from bank to
bank to minimize disturbance of wooded areas. Trees on the non-working bank
will be preserved. All exposed banks will be sloped and seeded to reduce
siltation, except in locations where riprap will be required. Where
practicable, the landscaping plan will include plantings of native species of
trees and shrubs. Tree plantings will consist of oaks, hawthorn, and red
mulberry.
SEDIMENTATION CONTROL MEASURES
Applicable measures described in the Erosion and Sediment Control
Planning Manual issued by the North Carolina Sediment Control Commission will
be incorporated during development of project plans and specifications. These
measures will include some or all of the following: construction sequencing,
timely establishment of vegetation, temporary runoff diversions, temporary
slope drains, and temporary stream crossings. Also, the improved channel will
include a sediment retention basin at the downstream end of the project. This
deposition basin will be designed to prevent sediments from construction
activities from reaching the portions of Hominy Swamp downstream from the work
area. This sediment retention basin will be maintained as necessary during
project construction and until the cut slopes become stabilized.
15
PROJECT CONSTRUCTION
The project will be constructed using draglines and other earth-moving
equipment. Approximately 37,000 cubic yards of material will be excavated from
the channel. This material will consist of soil, vegetation, and debris. No
rock excavation is anticipated.
DISPOSAL AREAS
Disposal activities will consist of placement of earth and debris. The
City of Wilson has proposed a 12-acre upland site on the north side of Raleigh
Road (see figure 1) for project disposal. Other sites may be considered during
preparation of project plans and specifications.
REAL ESTATE REQUIREMENTS
Real estate requirements for the project consist of the following: 10.90
acres for clearing and snagging, 15.99 acres channel excavation, and 12.00
acres for disposal. These areas are based on a project perimeter of 55-feet on
either side _ of the center line ;_(110 -feet total width) in the - channel widenin
anel 69 feet! en efther s±de of the center e (IOU ee total width) in
the clearing and snagging reach. The existing channel bottom width varies from
4 to 20 feet. The work area will be contained within the perimeter, but will
alternate from side to side, based on soil conditions, topography, and the
proximity of development.
Estimated real estate costs are shown in table 3, following page. It
should be noted that the 5.19 acres zoned residential for which the channel
improvement easement is to be acquired has a zero value. This is due to
e
land along a project is predicted to increase after the project; in this case
property values are expected to increase along Hominy Swamp due to the
decreased flood risk (see appendix D for additional discussion).
16
TABLE 3
Estimated Real Estate Costs, Selected Plan of Improvement
Item Cost
LANDS
Dredge Material Placement Easement:
12.0 acres zoned residential $254,853
Channel Improvement Easement:
5.19 acres zoned residential 0
10.80 acres zoned commercial 149,791
Clearing and Snagging Easement:
10.90 acres zoned rural 3,563
Total (30.89 acres) $408,207
Contingency $102,052
Total, Lands plus Contingency $510,259

ACQUISITION COSTS FOR 51 OWNERSHIPS
Federal $ 38,250
Non-Federal 102,000
Total, Acquisition Costs 140,250
Contingency 35,063
Total, Acquisition Costs plus Contingency $175,313
Total Estimated Real Estate Costs $685,572
RELOCATIONS
No relocations will be required for project construction.
PROJECT MAINTENANCE
The City of Wilson will be responsible for project maintenance.
Maintenance will consist of mowing grass, applying herbicide to the riprapped
areas, and repairing eroded areas. An operation and maintenance manual will be
provided to the sponsor after construction has been completed.
r
17
PLAN ACCCMPLISHMENTS
The Selected Plan of Improvement is expected to lower flood stages in the
reaches of Hominy Swamp where flood damages are most severe. Table C-8, page
C-9, appendix C, shows water surface elevations and stage reductions at
representative. locations for existing and improved conditions. Overall, the
Selected Plan of Improvement will reduce flood damages in the Hominy Swamp
basin by approximately 46 percent. An economic evaluation of project
accomplishments is presented below.
EXPECTED ANNUAL BENEFITS
Expected annual benefits for the Selected Plan, shown in table 4, are
estimated at $646,000. All benefits are based on damages prevented to existing
development. No benefits were computed for possible future development.
TABLE 4
Expected Annual Benefits ,for..Se.lectssi_Plan of .Improvement-- - -
Flood
Damage
Category Average
Annual
Benefits Percent
of Total
Residential $ 96,000 15
Commercial 57,000 9
Industrial 439,000 68
Utilities 23,000 4
Transportation 9,000 1
Emergency Costs 22,000 3
Total $646,000 100
18
ECONOMIC COSTS
Determination of the economic costs of the Selected Plan consists of two
basic steps. First, project first costs are computed. First costs include
expenditures for design and construction and related costs of supervision and
administration. First costs also include lands, easements, and rights of way.
Second, average annual costs are computed. These costs consist of
interest and amortization of the initial investment, and the annual cost of
project operation and maintenance. The average annual costs provide a basis
for comparing project costs to project benefits, discussed previously. A
summary of cost computations for each of these two steps is presented below.
Project First Costs - The first costs of construction for the Selected
Plan are estimated at $2,401,000. A summary of first costs is presented in
table 5, following page. A detailed cost estimate is presented in appendix F.
Interest During Construction - Interest during construction (7-5/8
percent interest rate, 12-month construction period) is estimated at $70,000.
The sum of the project first cost and interest during construction is referred
to as the project investment cost, and is used in computing average annual
costs, discussed below. The project investment cost is $2,471,000 ($2,401,000
first cost plus $70,000 interest during construction).
Average Annual Costs. - Average annual costs consist of interest and
amortization of the initial investment over an assumed project life of 50
years. Operation and maintenance costs are also included. The interest rate
used is 7-5/8 percent. Average annual costs are estimated at $215,319
($193,319 interest and amortization plus $22,000 operation and maintenance).
BENEFIT-COST RATIO
With expected annual benefits estimated at $645,875 and average annual
costs estimated at $215,319, the benefit-cost ratio for the Selected Plan of
Improvement is 3.0.
19
TABLE 5
Project Cost Summary, Selected Plan of Improvement
(October 1995 price levels)
Item Cost
LANDS AND DAMAGES
Acquisition Cost
Real Estate Analysis $6,000
Acquisition by Project Sponsor $128,000
Review of Sponsor Acquisition $48,000
Review of Sponsor Appraisal $1,000
Acquisition Costs, Subtotal $182,000
Land Payments by Project Sponsor $510,000
LANDS AND DAMAGES, TOTAL $692,000
Disposal Areas
Spread Material $27,000
Temporary Silt Fence $16,000
Seeding $26,000
Construction Entrance $2,000
Disposal Areas, Subtotal $71,000
Bank Stabilization
CSX Railroad Fill $13,000
Bank Stabilization, Subtotal $21,000
Associated General Items
Excavation $325,000
Clearing and Snagging $188,000
CSX Railroad Culvert Addition $587,000
Other Culvert Modifications $2,000
Construction Entrances $7,000 '
Seeding $138,000
Landscaping $57,000
Associated General Items, Subtotal $1,303,000
CHANNELS AND CANALS, TOTAL
PLANNING, ENGINEERING AND DESIGN
CONSTRUCTION MANAGEMENT
HOMINY SWAM, RECOMMENDED PLAN
$1,394,000
$214,000
$101,000`
$2,401,000
20
ENVIRONMENTAL IMPACTS
Impacts on significant, or potentially significant, resources of the
study area are summarized below, and are discussed in detail in the attached
environmental assessment.
o Water Quality - Impacts to water quality from project construction are
expected to be minor and temporary. Due to the absence of vegetative canopy
over most of Hominy Swamp, no change in water temperature is expected.
Additional sediments will probably be introduced into the stream during
construction. However, sedimentation control measures are included in the
project plan to minimize these impacts. No violations of State water quality
standards are expected outside of a reasonable mixing zone.
o Vegetation and Wetlands - Some wooded areas within the project right
of way will be disturbed by construction activities. However, landscape
plantings will reduce the net loss of vegetation, and this impact is not
considered significant. No adverse impacts to wetlands are anticipated.
o Fish and Wildlife Resources - There will be some loss of wildlife
habitat due to_removal of riparian vegetation along the project right of way.
However, impacts to wildlife resources are not expected to be significant,
given the disturbed nature of existing habitat along the stream banks. Adverse
impacts on aquatic resources are expected to be minor and temporary. Fish
populations impacted by construction activities are expected to return to pre-
construction levels soon after completion of the project.
o Esthetic Resources - Given the degree of disturbance and degraded
visual quality along Hominy Swamp, the Selected Plan will have minimal impacts
on esthetic values. Replanting of the disturbed areas and right of way will
provide visual screening and increase the esthetic compatibility of the project
with the existing landscape.
o Threatened and Endangered Species - The project is not expected to
affect these species. This finding is being coordinated with the U.S. Fish and
Wildlife (see page 23).
EFFECTS ON HAZARDOUS AND TOXIC WASTE POTENTIAL
No effects on hazardous and toxic waste sites will occur due to project
construction and operation.
HYDROLOGIC IIPACTS
The principal hydrologic effect of the project plan will be a reduction
in flood stages on Hominy Swamp. The hydrologic impacts of the project were
also evaluated to determine whether the improved channel could result in
undesirable impacts, including increased discharges and flood elevations
downstream from the project. Results of these investigations indicated that
any increase in downstream peak discharge due to the project would be
insignificant. Water surface profiles are shown on plate C-6, appendix C.
21
IMPACTS ON THE FLOOD PLAIN AND COMPLIANCE WITH EO 11988
Executive order 11988 requires that water resources projects be designed
to avoid inducing development in the 100-year flood plain. As discussed
previously, all flood damage reduction benefits attributed to the project are
based on damages prevented to existing development. No increased development
in the 100-year flood plain is anticipated.
IMPACTS ON MAZMDE RESOURCES
Generally, the impacts of the Selected Plan of Improvement on development
along Hominy Swamp will be beneficial, due to the reduced flood hazard.
However, portions of both commercial and residential lots will be acquired (see
appendix D). Construction and maintenance will result in no displacement of
person. .
PUBLIC VIEWS
i son, the non-Federal
sponsor, and the U.S. Fish and Wildlife Service. Coordination with other
interested agencies and individuals will be accomplished with circulation of
this Detailed Project Report and Environmental Assessment.
VIEWS OF NON-FEDERAL SPONSOR
The City of Wilson has indicated it supports the Selected Plan of
Improvement, and intends to fulfill the requirements of non-Federal sponsorship
- pen ix
A).
VIEWS OF THE U.S. FISH AND WILDLIFE SERVICE
In their. draft Fish and Wildlife Coordination Act Report (see appendix
B), the Service recommended measures to be incorporated into the project plan."
The Service's recommendations and the extent to which they have been
incorporated into the project are discussed below.
1. Recommendation. In the southern part of the project area where work will
be limited to clearing and snagging, no rooted trees, alive or dead, should be
cut unless they are leaning over the channel at an angle greater than 20
degrees off vertical, have severely undercut or damaged root systems, or are
relying upon adjacent vegetation for support (McConnell and Zerfoss 1982). All
trees and debris removed from the project area should be transported to an
approved upland site for disposal.
Response. Clearing and snagging includes removal of fallen trees and cutting
of saplings and bushy undergrowth. Larger canopy trees will remain because
only the tree trunks are in the flow area and do not create significant
hydraulic resistance. Furthermore, it is beneficial for these trees to remain
because the roots help to maintain bank stability and the shade promotes fish
habitat by reducing water temperatures. All debris will be removed from the
project area and transported to an approved upland site for disposal.
22
2. Recommendation. All areas cleared for construction should be landscaped in
order to provide maximum wildlife habitat and stream shading. Mast-producing,
hardwood trees, such as oaks (Quercus spp.) and hickories ?Carya spp.), spaced
widely along this stream bank would shade the stream and help stabilize the
banks without causing significant impediments to water flow in the channel.
The Corps should work with the local sponsor to develop a maintenance program
which enhances wildlife habitat. One beneficial aspect of such a plan would be
to schedule the mowing of herbaceous vegetation on bank areas at a minimum
" interval of once during the midsummer every two years.
Response. Mast producing hardwoods will be planted in the right of way
corridor. The Corps will work with the City of Wilson to develop a maintenance
program which will enhance wildlife habitat.
3. Recommendation. In order to minimize erosion during construction, the
clearing and stabilization of the banks should be conducted in stages. After
each segment is cleared of all vegetation, it should be graded and stabilized.
Each bank segment should be stabilized prior to initiating construction on the
adjacent segment. All spoil removed from the project area should be
transported to an approved, upland site for disposal.
Response. The clearing and stabilization of the banks will be conducted in
stages in order to minimize erosion during construction. All debris will be
transported to,an approved, upland site for disposal.
4. Recommendation. To protect downstream aquatic habitats from sedimentation
problems caused by project construction, the sediment trap to be created
downstream of the project should be maintained by cleaning during construction
and for a specified period of time thereafter to allow the banks to be
stabilized with vegetation. Cleaning should be undertaken whenever the trap
become half full. This cleaning would insure that sudden periods of heavy rain
would not cause the trap to overflow.
Response. A sediment trap will be constructed downstream of the project to
minimize movement of sediments from the construction site to areas downstream
of the project. This sediment trap will be maintained until the banks are
stabilized with vegetation. Cleaning will be undertaken by the City of Wilson
whenever the trap becomes half full.
5. Recommendation. Consultation, pursuant to Section 7 of the Endangered
Species Act of 1973, as amended, should be completed, and the Corps should
assess and minimize potential adverse effects on the Federally-listed
threatened and endangered species which may occur in the project area.
Response.Based on an analysis of the project (see the Environmental Assessment)
effects on Threatened and Endangered species, it has been determined that the
project is not likely to adversely affect any listed species. This finding is
being coordinated with the U.S. Fish and Wildlife Service.
23
SECTION V - DIVISION OF PLAN RESPONSIBILITIES
Costs for project construction will be shared by the Federal Government and
the non-Federal sponsor. Under current Federal policy applicable to flood
damage reduction projects, the non-Federal sponsor must contribute a minimum of
35 percent of the project first costs. The non-Federal contribution must
include (1) all lands, easements, rights of way, relocations, and disposal
areas; and (2) a minimum cash contribution of 5 percent of project first costs.
The above required contributions total $767,000 or 32 percent of the project
first costs. To comply current Federal policy of a minimum 35 percent
requirement totaling $840,000, the non-Federal cash contribution is increased
to $193,000 or 8 percent of the project first costs. Cost sharing for the
Selected Plan' of Improvement is shown in table 6, below. Additional
requirements of non-Federal sponsorship are included in the District Engineer's
"Recommendations," page 26.
TABLE 6
Cost Sharing, Selected Plan of Improvement
Non-Federal Share of First Costs:
Lands, Easements, and Rights of Way $647,000
Cash Contribution (8% of $2,401,000
from table 5, page 20)
193,000
Non-Federal Share of First Costs $840,000
e era are o F irst Costs: $1,561,000
Total Project Costs $2,401,000
The reviewer will note that the Lands, Easements, and Rights of Way figure
shown above ($647,000) differs from the "Real Estate" figure shown in table 5,
page 20. The total shown in table 5 includes Federal costs for real estate
acquisition and appraisal, in addition to non-Federal real estate costs.
24
SECTION VI - CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS
I have concluded that channel improvements to reduce flood damages on
Hominy Swamp at Wilson, North Carolina are economically justified and are
environmentally acceptable. Accordingly, Federal implementation of these
improvements is recommended.
RECObVENDATIONS
I recommend that the Selected Plan of Improvement, described herein for
purposes of flood damage reduction along Hominy Swamp at the City of Wilson,
North Carolina, be authorized for implementation as a Federal project, with
such modifications as in the discretion of the Chief of Engineers may be
advisable, at a first cost to the United States presently estimated at
$1,561,000, excluding interest during construction. The recommended plan
consists of channel improvements over a 2.1-mile reach of Hominy Swamp.
Recommendation of this plan is made provided that, except as otherwise provided
in these recommendations, the exact amount of non-Federal contributions shall
be determined by the Chief of Engineers prior to project implementation in
accordance with the following requirements to which non-Federal interests must
agree prior to implementation:
a. Provide all lands, easements, and rights of way, including suitable
disposal areas as may be determined by the Chief of Engineers to be necessary
for construction and subsequent maintenance and inspection of the project.
b. Accomplish without cost to the United States all relocations and
alterations of buildings, transportation facilities, and other structures and
improvements made necessary by the construction.
C. Provide, during the process of construction, an amount equal to not
less than 35 percent of total project costs, at least 5 percent of which will
be cash. The amount to be provided shall include the value or cost of all
lands, easements, rights of way, and facility and utility alterations and
relocations necessary for construction and subsequent maintenance of the
project, including suitable excavated material disposal areas, as may be
determined by the Chief of Engineers.
d. Hold and save the United States free from damages due to project
construction and subsequent maintenance, except damages due to the fault or
negligence of the United States or its contractors.
e. Maintain and operate the project after completion without cost to the
United States in accordance with regulations prescribed by the Secretary of the
Army.
f. At least annually inform affected interests that the channel will not
provide complete flood protection.
g. Assume full responsibility for all project costs in excess of the
Federal cost limitation of $5,000,000.
25
h. Prior to construction, adopt ordinances and promulgate regulations to
prevent encroachment on the flood plain storage areas, channels, and rights of
way and address the following:
(1) Maintain eligibility for the National Flood Insurance Program and
provide for a program of flood insurance within the project area.
(2) Allow no additional development in the 100-year floodway along w
Hominy Swamp which would adversely affect flood flows or would be susceptible
to significant damages.
(3) Adopt building codes, zoning ordinances, subdivision, regulations,
and other contracts as may be necessary to establish minimum floor elevations
of structures and other construction criteria for future developments in the
flood-hazard areas to prevent future flood damages.
i. The project sponsor shall publicize flood plain information in the area
concerned and shall provide this information to zoning and other regulatory
-- - --- agene-ies---f-or -t-heir----gu dance--and-.-,leadership---in___ preventing_ --unwise-_--future ---- _
development in t e oo pain an in a op ing suc regulations as may Be
necessary to prevent unwise future development and to ensure compatibility with
protection levels provided by the project.
j. Assume financial responsibility for cleanup of hazardous and toxic
waste, as defined in the Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA), which is necessitated by the project. Such costs
will not be considered part of the total project costs, nor will the sponsor
k. Fulfill the requirements of non-Federal cooperation as specified in the
Uniform Relocation Assistance and Real Property Acquisition Policies Act of
1970 (PL 91-646).
The recommendations contained herein reflect the information available at
this time and current Departmental policies governing formulation of individual
projects. They do not reflect program and budgeting priorities inherent in the
formulation of a national Civil Works construction program nor the perspective
of higher review levels within the Executive Branch. Consequently, the
recommendations may be modified before they are transmitted to higher authority
as proposals for authorization and implementation funding.
In making the recommendations herein, I have considered all significant
aspects in the overall public interest, including environmental, social,
cultural, and economic effects and engineering feasibility. No significant
environmental impacts will result from implementation of the recommended plan.
JES H. ?Y, 4E.r
?FChief, Technical Servics Division
26
v
US Army Corps
of Engineers.
Wilmington District
ENVIRONMENTAL ASSESSMENT
ENVIRONMENTAL ASSESSMENT
HOMINY SWAMP
FLOOD REDUCTION PROJECT
CITY OF WILSON, NORTH CAROLINA
Table of Contents
1.00 PROJECT AUTHORIZATION .................................EA-1
2.00 PROJECT DESCRIPTION..... .... ................EA-1
2.01 General Setting ................................. EA-1
2.02 Proposed Action ................. ..............EA-2
3.00 ALTERNATIVES ......... ........... ... EA-3
3.01 No-Action Alternative ........................... EA-4
4.00 ENVIRONMENTAL EFFECTS .................................EA-4
4.01 Water Quality EA-4
4.02 Aquatic and Terrestrial Resources ...............EA-5
4.03 Threatened and Endangered Species ...............EA-8
4.04 Archaeological and Historical Resources ......... EA-10
4.05 Esthetic Resources ............ ........ .....EA-10
4.06 Flood Plain . ............. .....................EA-10
4.07 Air Quality . ............... .. EA-10
4.08 Noise . ................... EA-11
4.09 Hazardous and Toxic Waste .......................EA-11
5.00 ENVIRONMENTAL COMMITMENTS ............................EA-12
6.00 COORDINATION .............................. .........EA-13
7.00 LIST OF RECIPIENTS . E
8.00• REFERENCES ...................................... ...EA-14
9.00 FINDINGS ... ..... EA-15
List of Tables
Table 1. Fish Sampled in Hominy Swamp. .. ..... EA-5
Table 2. Plant Species Noted Along` Hominy Swamp . .......... EA-7
List of Attachments
Attachment A. Section 404(B)(1) Evaluation.
ea-i

_
7 ,
ENVIRONMENTAL ASSESSMENT
HOMINY SWAMP
FLOOD DAMAGE REDUCTION PROJECT
CITY OF WILSON, NORTH CAROLINA
,.,
1.00 PROJECT AUTHORIZATION
The study was conducted under the authority of Section 205
of the 1948 Flood Control Act, as amended. The study was
requested by the City Manager of Wilson, on behalf of the City
Council of the city of Wilson, by letter dated September 9,
1991.
2.00 PROJECT DESCRIPTION
2.01 General Setting.
The Hominy Swamp watershed is located in the Middle Neuse
River Basin (from Falls Reservoir to New Bern).. Hominy Swamp
originates northwest of the city of, Wilson, near the Wilson
County Airport, and flows in a southeasterly direction through
the city to its confluence with Contentnea' Creek, a major
tributary of the Neuse River (see figure 1, main report). Urban
residential and commercial developments are the dominant land
uses adjacent to Hominy Swamp in the city of Wilson. Downstream
from the city of Wilson's wastewater treatment plant to
Contentnea Creek, Hominy Swamp is bordered by swamp forest and
bottomland hardwoods with agriculture being the predominant land
use beyond the flood plain. The Hominy Swamp study area extends
from. its---headwate-rs t-o -it.s.- confluence- with Cont-entnea. Creek...,-
Hominy Swamp has been subjected to extensive channel
zation in the city of Wilson to relieve urban flooding.
Maintenance of the channel and streambank occurs on an as=needed
basis. The most recent maintenance was performed by the city of
Wilson in 1994 and involved clearing and snagging along portionsE`
of the creek upstream of Highway 3.01 bridge to Elizabeth Road
clearing' and snagging was performed only in areas where the
city-owned property (Mills, 1995)
The width of Hominy Swamp at Raleigh Road is approximately
4 feet wide and increases to 'approximately.. 10 feetwide in the
vicinity of the city of Wilson's wastewater treatment plant. The
banks of the stream are steep, sandy and stable in areas where
vegetation is present. In other areas where vegetation is,
lacking, the 'banks are eroding The streambed in the proposed
project area (-from Black Creek Road to Goldsboro Street) is
comprised of sand and silt and is unvegetated with some snags
and urban debris present.
2.02 Proposed Action. a
The recommended plan consists of various channel improve-
ments or clearing and snagging over the project length of
approximately 2.1 miles (see figure 3, main report). Beginning
at the downstream end,: clearing and snagging will extend from
the bridge at,51ack ea approximately mile
to the trestle on a railroad spur line. The channel will be
widened to a bottom width of 25 feet from this. railroad, spur
through the :fill under the CSX railroad main `line' to. make the
improved conditions continuous.
Clearing and snagging will consist of removal of urban and
woody debris from the streambed and selected cutting of saplings
:and underbrush along the streambank, with a '`view toward
maintaining the stability of the banks. Large trees will not be
•.-1 ucrilyJ cl vt: i. cal L 11 ty :.tit 1,v L_J.i
channel, and thus becoming debris. rChanneFl,,r widening,,
n.cr.ease,._;r,the_ : channel :? bottom width to--
feet. The :; existing
?Uehannel bottoinc width sapprox imatel .°?20. eet. In addition, the
channel bottom willbe deepened by 1 .5 feet over a reach of
approximately 300 feet to provide a continuous slope. The
location of this reach is from Ralston Street (the street above
the railroad spur line) to approximately 200 feet below the
railroad spur line. Side slopes will be 1 horizontal to 1
vertical. Approximately 40,000 cubic yards will be removed and
transported to the disposal area from channel widening: and
deepening.
Project construction would generally be limited to one
bank at any particular point, with the working bank alternating
from 'side `to side to minimize impacts to existing features along
the :'.stream. Excavation of both banks will be. ..necessary in
transition areas where the channel improvement switches from one
bank to the other, and in any areas 'where : slopes need dressing
for stability. Slope and stream bottom protection will. be
required immediately downstream of the railroad culvert where
velocities would otherwise result in erosion. A concrete apron
will extend approximately 5 feet from the outlets' of the
existing culvert and the new culvert. Riprap will extend from
EA-2
the end of the concrete apron approximately 15 feet. From that
point, riprap will be needed on the slopes only and will extend
another 30 feet. A total of about 150 cubic yards of riprap
" will be needed.
In general, a 30-foot-wide right-of-way will extend from
the top of the improved bank on either side of the stream. The
right-of-way will be less than 30 feet wide at any locations
where existing structures are less than 30 feet from the
improved top of bank. Rights-of-way will be used for project
construction and maintenance access and for landscaping
measures. They will be cleared as needed to facilitate
construction.
A sediment trap will be provided near the downstream end
of the channel widening to prevent sediment resulting from the
construction activities from `being carried. farther downstream.
It will consist of a deepened area within `the'stream bottom; no
riprap or outlet structures are planned. Dimensions of the
sediment trap and construction details will be 'determined during
development of plans and specifications. Sediment collecting in
the sediment trap will be stopped when the upstream banks
stabilize.
Maintenance of the project will be performed by the city
of Wilson. Maintenance of right-of-way corridors in the channel'
widening portion will likely consist of mowing at regular
intervals. In the--area that is to be cleared and snagged,
maintenance will consist of cutting back and removing shoots
from the stumps that will remain after--initial clearing. During
maintenances any bank erosion will be repaired and snags in the
stream will be removed.
3.00 ALTERNATIVES
Three alternative bottom widths were evaluated for channel
improvement on Hominy Swamp (see page 11, main report). The
proposed plan is the smallest of the channel widths evaluated.
Channel improvements of greater length were also evaluated, but
were determined to be economically infeasible.
EA-3
3.01 No-Action Alternative.
The no-action alternative is no flood control project. This
alternative could result in significant adverse social and
economic impacts to the community. Without a flood control
project, it is anticipated that flood damage will continue to be
experienced within the flood plain of the study area.
4.00 ENVIRONMENTAL EFFECTS

4.01 Water Quality.
Hominy Swamp, from its origin to its confluence with
Contentnea Creek, is classified C Swamp waters (C-Sw) by the
- -io r h - -
-ILL
le e 0 _ 1. _ ..tom _I
S
secondary contact recreation (:wading and fishing, fish and
wildlife, propagation, and agriculture). The Sw designation
identifies streams that drain swamplands. The State water
quality standards for pH and dissolved oxygen (DO) in swamp
waters are lower than those assigned to class C waters. The
project is not expected to have a significant long-term effect
on water quality.
There is one known permitted wastewater discharge to
Hominy Swamp. Williamson Produce discharges up to 9,000 gallons
of water a day from their operation at Highway 301 and Hominy
Swamp. A condition of the National Pollutant Discharge
Elimination System (NPDES) permit for the discharge is that not
more than 9,000 gallons of water are discharged per day (Nizich,
1995).
A Section 401 (P.L. 95-217) water quality certificate is
required from the North Carolina Department of Environment,
Health, and Natural Resources, Division of Environmental
Management, Water Quality Planning, Raleigh, North Carolina, and
has been requested.
A Section 404(b)(1) evaluation report has been prepared and
is included as attachment A. A Section 404 public notice will be
sent out for a 30-day review concurrent with the public review for
the EA. Other .than,,the creek channel, ,there does not exist any
wetla-nds subj-ect ? to- Sec-tion - 404---of the Clea-n- Wa-te'-r',-Act .
No adverse impacts to groundwater resources are expected to
occur as a result of the proposed activity.
EA-4
4.02 Aquatic and Terrestrial Resources
In the project area, the stream bottom is comprised of
unstable sand and silt with little instream vegetation. The
stream bottom is occasionally strewn with trash,' principally
bottles and tires. The streambanks are generally in poor
condition, sparsely vegetated, eroding and/or vertically walled
with sandbags or boards. At several locations, sanitary sewer
crossings `pose a barrier to the flow of water and cause rafting of
trash which impedes the flow of water. -The'?stream,is' unshaded for
most ,_o;f its .i.ength
71Fisheries resources in Hominy Swamp were sampled by
personnel of the U.S. Army Corps of Engineers, the U.S. Fish and
Wildlife Service and the North Carolina Wildlife Resources
Commission on May 1, 1987. Fish habitat and terrestrial and
wildlife' resources were documented at each station. Analysis of
field sampling data showed a low number of fish species. Six
different species of fish were identified in Hominy Swamp (table
TABLE 1
FISH SAMPLED IN HOMINY SWAMP
Sampling was performed by electro-fishing for 15 minutes at
three stations: Station 1 was at city of Wilson Wastewater
Treatment Plant; Station 2 was at the Norfolk and Southern
Railroad; Station -3 was at Canal Drive.
Date of sampling: May 1, 1987.
Common Name Scientific Name Station Number Taken,
Mosquitofish Gambusia affinis 1,2,3 Uncounted Dozens
American eel Anguilla rostrata 2 1
Pumpkinseed Lepomis gibbosus 1 4
Warmouth Lepomis gulosus 1 1
Bluegill Lepomis machrochirus 3 1
Green sunfish Lepomis cyancellus 3 1
A mollusk survey was performed on Hominy Swamp on June 22,
1990, in order to-determine if the dwarf wedge mussel (Alasmidonta
heterondon) was present. .,The dwa-rf wedge mussel is listed under
the Endangered Species Act. of 1973, as' amended. There were five
sampling stations during the survey. No dwarf wedge mussels, or
any other native ;species of bivalve, were found in the study area.
The Asian clam, an introduced species, was the only bivalve found
All other species were gastropods. All of the species found were
pollution tolerant. organisms and `have- been noted to occur in
disturbed or degraded waters. Suitable habitat for the dwarf
wedge,_. mus'sel' was not found since the --stream appeared to " be
severely degraded as a result of past channelizations, severe
se men a ion, an poor wa er qua y.
Bibb soil -series have been mapped along Hominy swamp within
considered prime or unique soils associated with prime and unique
farmlands (Hayes, 1995) .
Land use adjacent to Hominy Swamp from the railroad spur
line upstream;is primarily urban, and the vegetation and wildlife
communities present reflect this condition. The right-of-way for
the existing channel is well maintained, which prohibits the
..... -.. ?..1....... ... v? - u v ?. y.? ?.u--L Vai ?vJLUILUisi l-.y i;JQy U11U .... CCit 1y JUC''I.CJ'A1U11'U 1.
-stages. North of US Highway 301 the streambank.has no mature
trees` within the proposed project area. The banks have dense
growth of small; wooded, regrowth vegetation and herbaceous'
plants. Adjacent to residential and city park property the banks;
are grassed. From the railroad crossing below US Highway 301 to
.Black Creek Road, the stream supports a palustrine forest
dominated by,bottomland hardwood.trees. Some plant"species noted
along Hominy `Swamp during 1987 and a field trip to the project'
area in June-1995 =are listed in table 2 (see next page).
The wildlife habitat values for the project area have been
greatly diminished, because,-of the intensity of urban development.
The fragmented nature of the remaining wooded habitat provides
food and cover only for those.wildlife ;species commonly associated
with urbanized areas. Birds. are the most obvious fauna
constituent of the area, appearing with abundant numbers and a
high species diversity.' The most common mammalian forms include
rodents, opossums, and raccoons. Reptile and amphibian populations
are low, compared to those found in' unaltered swamp forest
habitat.
TABLE 2
PLANT SPECIES NOTED ALONG HOMINY SWAMP
Common Name
Scientific Name
Trees:

Red maple Acer rubrum
Sweet gum Liquidambar styraciflua
Sycamore Platanus occidentalis
Water oak Quercus nigra
River birch Betula nigra
Tulip popular Liriodendon tulipifera
Loblolly pine Pinus`taeda
Shrubs and Vines:
Black willow Salix nigra
Privet Ligustrum sp.
Greenbrier smilax sp.
Red bay, Persea borbonia
Grape Vitis SP.
Honeysuckle Lonicera japonica
Elderberry Sambucus canadensis
Ironwood Carpinus caroliniana
Cross vine Anisostichus capreolata
Poison ivy Rhus toxicodendron
Herbs and Grasses:
Unidentified grasses _ Family POACEAE
Southern cane Arundinaria gigantea
Violets Viola sp.
EA-7
4.03 Threatened-and Endangered Species.
The U.S. Fish'and Wildlife Service (1995) provided a list
of species which could potentially occur within the project
area. Under Section 7 of the Endangered Species Act of 1973, as
amended, potential project impacts on these species must be
assessed. These species are as follows.
Species Status
red-cockaded"woodpecker (Picoides borealis) Endangered
dwarf wedge mussel (Alasmidonta heterodon) Endangered
Michaux' s sumac (.Rhus M C auxi i n a e -
Species Assessments
pine forests in the southeastern United States. It requires
mature living pines, generally in excess of 75 years in age, for
excavation of nest cavities. Younger pine stands, while not
providing adequate nesting habitat, can be essential for
foraging and long-:term maintenance of the colony. The home
range of the species is variable, frequently conforming to
veaetati v m ortant landsca e features. Generally, winter
ome ranges are ar;ger an: e
season, but do not extend much more than a mile from the cavity
tree.
Historically, the project area probably offered
suitable habitat for the species Analysis of aerial
photographs and field surveys of the project area and adjacent
landscape during planning for this project indicate that there
is no longer any suitable habitat remaining,within,a mile of the
project area. The. area is now comprised primarily of
urban/ industrial land uses. Since the red-cockaded woodpecker
no longer resides -in the project area, it has been determined
that the project is not likely to 'adversely affect `the species.
Dwarf wedge mussel.' From historical data, it is known
that this species was once widespread in the Neuse River basin.
While there - are no records of it occurring in Hominy-Swamp;,.
based on its landscape position and the proximity of other
_nearby populations, there is every reason to believe that it was
once'an inhabitant of the stream.' Within the upper Contentnea'
Creek drainage, the dwarf wedge mussel is now limited to Turkey
.and Moccasin Creeks:, located above the existing Buckhorn
Reservoir. Extensive surveys of Contentnea Creek below Buckhorn
EA-8
Reservoir have been conducted by the city of Wilson, but no
additional populations have been found.
In 1990, the U.S. Army Corps of Engineers surveyed the
Hominy Swamp watershed to determine if the dwarf wedge mussel
was present. That survey found only three species of mollusks
in the stream: pewter physa (Physella heterostropha) creeping
ancylid (Ferrissia rivularis) and the bugle sprite (Micromenetus
dilitatus).- These are all pollution tolerant gastropods. The
degraded condition of the stream makes it totally unsuitable for
the dwarf wedge mussel. There is little likelihood that the
species has reoccupied the stream since that survey was
conducted. Stable benthic habitats take many years to recover
from disturbance events; indeed, there has never been a
documented instance of freshwater unionidae reoccupying a stream
once extirpated (Adams, 1990) Based on these; survey. results
and the continued degraded condition of the stream, it has been
determined that the project is not likely to adversely affect
the species.
Michaux's sumac. This species has two major habitat
requirements: sandy or. rocky acid soils and open growing
conditions. It appears to be intolerant of soil disturbance,
never having been noted to occur on an area that was previously
tilled or plowed (J. H. Carter, 1994). Its former distribution
on the "landscape , is unknown, but it was probably maintained over
a wide area by frequent fires. Indeed, fire suppression in the
twentieth century is believed to be one of the principle causes
of its decline. Only one population has ever been noted for
Wilson County and the species is now presumed to be extirpated
from the area (Murdock and Moore, 1993).
Michaux's 'sumac is not believed to occur in the project
area for the following reasons: (1) the original habitats
within thefproject'area were primarily swamp/alluvia! soils and
were, therefore., unsuitable; (2) historically, swamps such as
those occurring in this physiographic region were heavily
forested and would not provide the open conditions necessary.for.
the species; (3) the lower end of the project area is still
heavily wooded/shaded, and; (4) the upper end of the project has
been previously degraded by channelization with associated spoil
deposition piles. Since neither the original nor current
habitats of the project area were, or are, suitable for the
species, there is no reason to expect that it occurs there
today. For these reasons it has been determined that the project
is not likely to adversely affect the species.
Conclusion
Based on the above analysis, it has been determined that
the 'project is not likely to adversely affect any listed
species., This finding is being coordinated with, the U.S. Fish
and Wildlife Service.
4.04 Archaeological and `Historical Resources
44
In 1987, an archaeological reconnaissance and assessment of
Hominy Swamp' was` performed, including the' area of, the, proposed
,project.' During the course of the survey one historic period
-
archaeologica si a was` oca a bus ou 'side o if the przpzse-???
project area. Due to the paucity of cultural material and the
environmental characteristics of the corridor along Hominy Swamp,
i n=1 i n-Trco+-A .vn4-; eNeri Preservation Officer, by letter dated August 14, 1987, concurred
with this recommendation and found that this project would have no
effect upon significant archaeological resources.
4.05 Esthetic Resources.
While the esthetic quality of Hominy Swamp has been greatly
ailecL_ea -r)y une uegre-e e. human erreroaer?me
plain disturbances, the remaining riparian corridor along the
creek provides a pleasant visual contrast to surrounding
commercial and residential development. Between Black Creek Road
and the railroad spur fine the area is forested. The overall
visual quality of this area is moderate. Upstream of US Highway
301 to Goldsboro Street, land use adjacent to the stream is mainly '
residential with some industrial, commercial, and storage areas
The banks of the stream have been cleared throughout most of the
project reach as a result of previous channelization. The visual
quality is considered to below.
4.06 Flood Plaice.
No practicable 'alternative exists to performing the work
within the flood plain of Hominy Swamp'. The proposed action would
not affect the natural. and beneficial values of the flood plain. y
4.07 Air Quality.
The project is in 'compliance with Section 176 (c) of the
Clean Air Act (CAA), as amended. The State of North Carolina
has designated the project area as an attainment area. The
State of North Carolina has a State Implementation Plan (SIP)
EA-10
approved or promulgated under Section 110 of the CAA. However,
for the following reasons, a conformity determination is not
required:
a. 40 CFR 93.153 (b) of the CFR states, "For Federal
actions not covered by paragraph (a) of this section, a
conformity determination is required for each pollutant where
the total of direct and indirect emissions in a nonattainment or
maintenance area (emphasis added by the writer} caused by a
Federal action would equal or exceed any of the rates in
paragraphs (b) (1) or (2) of this section." The area has been
designated by the State of North Carolina as an attainment area.
b. The direct and indirect emissions from the project
fall below the prescribed de minimus levels (40 CFR 93.153 (c)
(1)) and therefore, no conformity determination will be
required. Construction at the project site would take
approximately 6 months. All construction equipment will be
removed from the project site following construction completion.
c. The project is located within the jurisdiction for air
quality of the Raleigh Reg-ional Field Office of the North
Carolina Department of Environment, Health, and Natural
Resources. The ambient air quality, for the city of Wilson and
Wilson County. has been determined to be in compliance with the
National Ambient Air Quality Standards. This project is not
anticipated to create any adverse effect on the air quality of
this attainment area. There will be some temporary increases in
air pollution created by construction equipment; however, the
pollution produced is no worse than that from any large piece of
machinery and should be readily dispersed. Air pollution is a
temporary impact.
4.08 Noise.
No significant impacts will occur. The noise level increase
in the immediate vicinity of construction will be temporary.
4.09 Hazardous and Toxic Waste.
} The North _Carolina "Department of Environment, Health, and
Natural Resources, Solid and Hazardous Waste Branch,. was contacted
regarding documented locations of solid waste. landfills and
hazardous waste 'sites in thestudy area. Based on their' records,
there are no documented solid and/or hazardous waste sites in the
project area (Ross, 1995). During the. site visits, the project
area' was for potential hazardous and toxic waste. No
visual evidence of HTW was found. One old landfill and/or
EA-11
hazardous and toxic waste site buried alongside 'of Hominy Swamp
below Ralston Street has been 'located (Bartlett, 1987). Work in
this area would be confined to the west bank of Hominy Swamp to
avoid any disturbance of the landfill. _
5.00 ENVIRONMENTAL COMMITMENTS
The following measures, have been incorporated into the
proposed.project"to"minimize or reduce potential effects of the
project on the environment.
a." Clearing an snagging ' nc u es remova o fallen
--?
debris and cutting of saplings and brushy undergrowth. Larger"
canopy trees will remain because only the tree trunks are in the
fa aid nroa snddo nnt-- rrgatP si cini :fi na-nt hydraulic resistance
- -
the roots help to maintain bank-- --stability and shade "from these"
trees' promotes fish and wildlife by preventing high water
temperatures. All debris will be removed from the project area
and transported to an approved upland site for disposal.
b. Hardwoods' will be planted in the right-of-way corri-
dor.
C. In order to minimize erosion during construction,"th"e
clearing` and stabilization of the banks will be conducted' in
stages After each segment is cleared' of all vegetation,` it
will be graded and stabilized. Each bank segment will be
stabilized prior to initiating construction on the adjacent
segment.` As far as it is practicable, the project will be
constructed in stages.
d. A sediment trap will be constructed' downstream of the
project to minimize movement of sediments from the construction
site to areas downstream of the project. This sediment trap -
will be maintained until the banks are stabilized -`with
vegetation.
EA-12
6.00 COORDINATION
Representatives from the following agencies were contacted
regarding the proposed action:
North Carolina Wildlife Resources Commission
U.S Fish and Wildlife Service, Raleigh, North Carolina
North.Carolina Department of Environment,. Health, and
Natural Resources
Wilson County Soil and Water Conservation District
No public meeting has been held However, Corps repre-
sentatives have met with the.city of Wilson city officials and
discussed options for a solution to the flood problem.
7.00 LIST OF RECIPIENTS
This environmental assessment (EA) is being circulated to
the following agencies and individuals
U.S. Environmental 'Protection Agency
Forest Service, USDA
U.S. Department of Housing and Urban Development
Advisory Council on Historic Preservation
National Oceanic and Atmospheric Administration
Center for Environmental Health
National Marine 'Fisheries Service.
State Clearinghouse
U.S. Department of Interior
U.S. Fish and Wildlife Service
Fifth Coast Guard District
Conservation Council of North Carolina
Sierra Club
Izaac Walton'League
Federal Highway Administration
National Audubon Society
North Carolina Wildlife Federation
National Wildlife Federation
Soil Conservation Service, USDA
U.S. Department of Energy
Cape Fear Community College
_ North Carolina Environmental Defense Fund
Duke University Department of Geology
North Carolina Division of Coastal Management
UNC-Chapel Hill Library
Librarian, North Carolina Environmental Resources Library
UNC-Wilmington Library
North Carolina State Library
City of Wilson
Wilson County
Wilson Soil and Water Conservation District
.
8.00 REFERENCES
:Adams, W F. 1990. A report on the conservation status of
=North Carolina's freshwater and terrestrial mollusks, pages
- in ams, W F. , A e man, K. U. ins; .
Gerberich, E. P. Keferl, H. J. Porter, and A. S. Van Devender.
1990. A report on the conservation status of North Carolina's
I, 'D N'Tr- UT 4
Barlett, Bill. 1987. City Engineer,, City of Wilson, Personal
Communication, Wilson:
Carter, J. H. 1994 Personal Communication, North `Carolina
Hayes, Ricky T. 1995. Wilson Soil and Water Conservation
Mills, Gary L. 1995. City Engineer, City of Wilson, Personal
Communication, Wilson,
Murdock, N. A. and J.'Moore. 1993 Recovery Plan for.Michaux's
sumac (Rh.us michauxii) Sargent. U.S. Fish and Wildlife Service,
Atlanta.'
Nizich, Greg. 1995. Permits Section, NC Department of
Environment, Health, and Natural Resources, Raleigh.
Ross, Scott. 1995. .Superfund- Section, NC Department of
Environment, Health, and Natural Resources, Raleigh.
U.S. Fish and Wildlife Service. 1995. Draft Fish and Wildlife
Coordinat-ion Report Hominy Swamp Flood `Control Project, Raleigh..
EA-14
9.00 FINDINGS

The proposed action should not significantly affect the
quality of the human environment; therefore, an Environmental
Impact Statement will probably not be prepared. If this opinion
is upheld following circulation of this EA, a Finding of No
Significant Impact will be signed and circulated.
SECTION 404 (b)(1) (PUBLIC LAW 95-217) EVALUATION
HOMINY SWAMP
FLOOD DAMAGE REDUCTION PROJECT
CITY OF WILSON, NORTH CAROLINA
EVALUATION OF SECTION 404(b)(1) GUIDELINES
40. CFR 230
Section 404 Public Notice No. CESAW-TS-PE-98-98-0004, dated November 21, 1997.
1. Review of Compliance (230.10(a)-(d)) Preliminary 1/ Final 21
A review of the NEPA Document
indicates that:
a. The discharge represents the least
environmentally damaging practicable
alternative and if in a special aquatic
site, the activity associated with the
discharge must have direct access or
proximity to, or be located in the aquatic
ecosystem to fulfill its basic purpose (if no, -
see section 2 and NEPA document); YESI_I NOI-1* YESI X I NOI-I
b. The activity does not:
1) violate applicable State water quality
standards or effluent standards prohibited
under Section 307 of the CWA; 2) jeopardize
the existence of federally listed endangered
or threatened species or their habitat; and
3) violate requirements of any federally
designated marine sanctuary (if no, see section
2b and check responses from resource and
water quality certifying agencies); YESI_I NOI-1* YESI X I NOI-I
c. The activity will not cause or contribute
to significant degradation of waters of the
U.S. including adverse effects on human
health, life stages of organisms dependent
on the aquatic ecosystem, ecosystem diversity,
productivity and stability, and recreational,
aesthetic, and economic values (if no,
see section 2);
d. Appropriate and practicable steps have
.been taken to minimize potential adverse
YESI-1 N01-1- YESI X I N0I-1
impacts of the discharge on the aquatic
ecosystem (if no, see section 5). YESI_I N01-1-
Proceed to Section 2
1, 2/ See page A-6.
YESI X I NOI_I
A-1

Not Signifi- Signifi-
2. Technical Evaluation Factors `(Subparts C-F) N/A cant cant*
a. Physical and Chemical Characteristics
of the Aquatic Ecosystem (Subpart C)
(1) Substrate impacts. I I X
(2) Suspended `particulates/turbidity I I
impacts. I I x
(3) Water column impacts. I X L
(4) Alteration of current patterns I I I -
and water circulation. I I < x
(5)' Alteration of normal water I I X I I'
uationsthydroperiod. 1
1'
-
(6) Alteration of salinity I I I I -- --
gradients. I X I
-a ahO
- *0 F!eee
Ae
m--e6---
i? erE•^•
.
Y
(1)
Effect on threatened/endangered
species and their habitat. I I X j
(2) Effect on the aquatic food web. I I X I
(3) Effect on other wildlife (mammals,
birds, reptiles, and amphibians). I I X
c. Snecial SAcuatic.Sites (SubDart E)
(1) Sanctuaries and refuges. I X I
(2) Wetlands. I-_ -X
(3) Mud flats. I X I
(4) Vegetated shallows: ( X
(5) Coral reefs. I X
(6) Riffle and pool complexes. I X I I 1
d. Human Use Characteristics (Subpart F)
(1) Effects on municipal and private I I I f'
water supplies: I I X 1
(2) Recreational and commercial
fisheries impacts. I I x
(3) ` Effects on water-related recreation. I I X
(4) Aesthetic impacts. I 1 X
(5) ; Effects on parks, national and
historical monuments, national
seashores, wilderness areas, I l
research sites, and similar
preserves. L I X
Remarks: Where a check is placed under
the significant category, preparer add explanation below.
Proceed to Section 3
"See page A-6. -
A-2

3. Evaluation of Dredged or Fill Material (Subpart G) 3/
a. The following information has been
considered in evaluating the biological
availability of possible contaminants in
dredged or fill material. (Check only
those appropriate.)
(1) Physical characteristics.. .. .. .. ............. :IXI
(2) Hydrography in relation to
known or anticipated
sources of contaminants... ... .............................I_I
(3) Results from previous
testing of the material
or similar material in
the vicinity of the project ......... ... ..... I_I
(4) Known, significant sources of
persistent pesticides from _
land runoff or percolation.. .................. ... . I_I
(5) Spill records for petroleum
products or designated
(Section 311 of CWA)
hazardous substances.. ...... ... • I_I
(6) Other public records of
significant introduction of -
contaminants from'industries,
municipalities, or other
sources ... .. ................ I_I
(7) Known existence of substantial
material deposits of
substances which could be
released in harmful quantities
to the aquatic environment by _
man-induced discharge activities....... .... ... ... I.I
(8) Other sources (specify).. .... ......... ... .. I_I
Reference:, EA "Hominy Swamp - Flood Damage Reduction Project, City of Wilson,
North Carolina;" dated October 1997.
b. An evaluation of the appropriate information in 3a
above indicates that there is reason to believe the
proposed dredge or fill material is not a carrier of
contaminants, or that levels of contaminants are sub-
stantively similar at extraction and disposal sites and
not likely to result in degradation` of the disposal site. _
The material meets the testing exclusion criteria. YES IXI NO 1_1-
Proceed to Section 4
3/, see page A-6.
A-3
4. Disposal Site Determinations (230.11(f)).
a. The following factors as appropriate,
have been considered in evaluating the
disposal site.
(1) Depth of water at disposal site. .. . . " . .... IXI
(2) Current velocity, direction, and
variability,at disposal site. IXI
(3) `Degree of turbulence........................................
1XI
(5) ° Discharge vessel speed and _
direction................ ...............
(7) Dredged material characteristics
(constituents, amount and type _
of material, settling velocities)... .... . ........... I-1
(8) Number of discharges per unit of
time ................... ... .. .. I_I
(9) Other factors affecting. rates and
patterns of mixing ,(specify)
List appropriate references.
Reference: `EA "Hominy Swamp- Flood Damage Reduction Project, City of Wilson,
North Carolina," dated October 1997.
b. . An evaluation of the appropriate factors in
4a above indicates that the disposal site _
and/or size of mixing zone are acceptable....." ............. YES IXI NO 1-1-
5. Actions to ;Minimize Adverse Effects (Subpart H).
All appropriate and practicable steps have been taken,
through application of recommendations of 23070-230.77,
to ensure minimal adverse effects of the proposed
discharge. List actions taken.. ......... , ........... . ....... YES IXI NO 1-1-
See Environmental Commitments, Section 5.00 of the EA.
Return to section 1 for final stage of compliance review. See also
note 3L page A-6.
`See page A-6:
A-4

6. Factual Determinations (230.11).
A review of appropriate information as identified in
items 2-5 above indicates that there is minimal
potential for short- or long-term environmental
effects of the proposed discharge as related to:
a. Physical substrate at the disposal site
(review sections 2a, 3, 4, and 5). ' YES IXI NO
' b. Water circulation, fluctuation, and salinity
(review sections 2a, 3, 4, and 5). YES IXI NO I_I*
c. Suspended particulatesAurbidity
(review sections 2a 3, 4, and 5). YES IXI NO I_I*
d. > Contaminant availability
(review sections 2a, 3, and 4). _ YES IXI NO -I*
e. Aquatic ecosystem structure and function YES IXI NO
(review sections 2b and c, 3, and 5).-
f. Disposal site
(review sections 2, 4, and 5). YES IN NO U*
g. Cumulative impact on the aquatic.
ecosystem. YES IXI NO I_I'
h.. Secondary impacts on the aquatic
ecosystem: YES %J NO 1_1*
7. Findings.
a. The proposed disposal site for discharge of
dredged or fill material complies with the
Section 404(b)(1) guidelines.. .. . .IXI
b. The proposed disposal site for discharge of
dredged or fill material complies with the
Section 404(b)(1) guidelines with the _
inclusion of the following conditions: ......... ........ ...........
I-
I
`See page A-6:
A-5
c. The proposed disposal site for discharge of
dredged or fill material does not comply with
the Section 404(b)(1) guidelines for the
following reasons(s):
(1) There is a less damaging, practicable alternative ................. I_I
(2) The proposed discharge will result in significant _
degradation of the aquatic ecosystem ......... ' ........... ........ I_I
(3) The proposed discharge does not include all
practicable and appropriate- measures to minimize
potential harm to the aquatic ecosystem . ... .
8.
Chief, Technical Services Div' ion
Date: `A negative, significant, or unknown response indicates that the permit application' may not be in
compliance with the Section 404(b)(1) Guidelines.
1/ Negative responses to three or more of the compliance criteria at this stage indicate that the proposed
projects may not be evaluated using this "short form procedure." Care should be used in assessing
pertinent portions of the technical information of items 2 a-d, before completing the final review of
compliance.
2/ Negative response to one of the compliance criteria at this stage indicates that the proposed project does
not comply with the guidelines. If the economics of navigation and anchorage of Section.404(b)(2) are to
be evaluated in the decision-making process, the "short form evaluation process is inappropriate."
3/ If the dredged or fill material cannot be excluded from individual testing, the "short-form" evaluation
process is inappropriate.
A-6
OF
w??Sn
z
s0 His
yNORTFI Cry
OFFICE OF THE
CITY MANAGER
September 9, 1991
CITY OF WILSON
nofA ealolina
1NGORVORATEO 1449
27894-0010
EAW-91-129
Colonel W. S. Tulloch
District Engineer
Wilmington District
U. S. Army Corps of Engineers '
P. 0. Box 1890
Wilmington, NC 28402-1890
Dear Colonel Tulloch:
The City of Wilson has been discussing and corresponding with the
U. S..Army Corps of Engineers ,*Wilmington District, concerning a
flood control project for Hominy Swamp for many years. Mr.
Lawrence W. Saunders' letter dated June 24, 1991, to Mr. William
P. Bartlett, Director of Public Works, outlined alternatives and
recommended proceeding with Section 205 of the Continuing
Authorities Program (CAP).
Captain Gregg Chislett, along with Messrs. Ronald Fascher and Rex
Phillips, made a presentation on the proposed Hominy Swamp Project
and the CAP on Monday, September 9, 1991. It is understood that
the City's. share of the second phase or feasibility study would be
fifty percent (500.), or $55,000.00. The City Council of the City
of Wilson requests, by this letter, that you proceed with the
feasibility study under the Continuing Authorities Program.
On behalf of City Council and City staff, I thank you and your
staff for their presentation. If additional information is
required, please do not hesitate to contact us.
Sincerely,
CITY OF WILSON
Edward A. Wyatt
City Manager
aih
c: Mayor and City Council
Charles W. Pittman, III, Assistant City Manager
William P. Bartlett, Director of Public Works
James B. Bradshaw, Director of Planning
Gordon R. Baker, Director of Finance
Enclosure 3.
P.O. BOX 10, WILSON, NORTH CAROLINA 27894-0010 PH:[phone] FAX:[phone]
EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER
1990 NATIONAL MEDIUM EMPLOYER OF THE YEAR FOR PERSONS WITH DISABILITIES - PUBLIC SECTOR
A --/
.
APPENDIX B
Report by US Fish and Wildlife Service
`I
HOMINY SWAMP FLOOD CONTROL PROJECT
DRAFT
FISH AND WILDLIFE COORDINATION REPORT
Prepared by
Howard F. Hall

Under the Supervision of
L. K. Mike Gantt
Supervisor
Released by
U. S. Fish and Wildlife Service
Raleigh Field Office
Raleigh, North Carolina
September 1995

United States Department of the Interior
FISH AND WILDLIFE SERVICE
Raleigh Feld Office
Pon Office Box 88726
Raleigh. North Carolina 27686.3726
September 11, 1995•
Colonel Robert J.
District Engineer
U.S. Army Corps of
P.O. Box 1890
Wilmington, North
Sperberg
Engineers
Carolina 28402-1890
Attached is the Service's Draft Fish and Wildlife Coordination Act Report for the
Hominy Swamp Flood Control Project, Wilson County, North Carolina. This report
identifies fish and wildlife resources located in the project area and the
potential effect of the proposed project on these resources. This report, when
finalized, will constitute the Service's report in accordance with Section 2(b)
of the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C.
661 et seq.) and our FY95 Transfer Funding Agreement and Scope of Work.
A copy of this report is being provided to the appr
review agencies, and their comments will be incorporated as soon as available.
Any comments which you or your staff wish to provide should be received by
October 20, 1995, so they may receive adequate and timely attention in
preparation of the Final FWCA report. Technical questions should be directed to
the attention of biologist Howard Hall who is handling this project. He may be
reached at 919-856-4520, ext. 27.
We appreciates the opportunity to provide this report, and we look forward to
continued coordination with the Corps regarding this project.
Sincerely yours,
LX K j4
L.R. Mike Gantt
Field Supervisor
FWS/R4:HHall:HH:09/11/95:919/856-4520 ext.27:B:\Homi ltr.995

EXECUTIVE SUMMARY
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Planning information pursuant to the U.S. Fish and Wildlife
Service's responsibilities is provided under the general
authority of the Fish and Wildlife Coordination Act, as amended
(48 Stat. 401; 16 U.S.C. 661 et seq.) and the FY95 Scope of Work
Agreement for the study of the Hominy Swamp Flood Control Project
conducted by the Wilmington District, U. S. Army Corps of
Engineers (Corps). The Hominy Swamp Project was authorized
within the Senate Public Works Committee Resolution of April 15,
1966 and House Document 175/89. The purpose of the project is to
reduce flood damage along portions of the waterway within the
City of Wilson, Wilson County, North Carolina. This report, when
finalized, will constitutes the Service's formal report required
under Section 2(b) of the Fish and Wildlife Coordination Act (op.
cited).
The Hominy Swamp study area extends from its headwaters near the
Wilson County Airport south to its confluence with Contentnea
Creek. The watershed consists of approximately 9,500 acres.
Since 1978, urban and residential development has significantly
reduced the proportion of natural and agricultural land.
Urbanization also has adversely affected the aquatic, riparian,
and floodplain fish and wildlife habitats of Hominy Swamp.
Previous channelization, channel clearing by the City of Wilson,-;
and intense, rapid urban and agricultural runoff create poor
quality aquatic habitat conditions and low species diversity.
The land surrounding the section of Hominy Swamp under study is
being developed at a rapid rate. The development of new
residential and commercial properties is resulting in an increase
in the amount of impermeable surfaces in the watershed and
associated increases in stormwater run-off. The channel has been
previously modified to enhance stormwater drainage of the
surrounding urban and residential lands. The creek's water
quality and availability of aquatic habitat is poor. There are
currently only limited existing biological resources of concern.
The opportunity for enhancing aquatic habitat is limited due to
the continual development of the watershed outside of the study
area. However, the Hominy Swamp watershed offers opportunities
for implementing fish and wildlife habitat conservation,
restoration, and enhancement measures.
Hominy Swamp does provide limited support for adaptable
invertebrates. The presence of some vegetation and a limited
invertebrate fauna suggest that Hominy Swamp can support some
vertebrate species. Several species of fish have been found in
the project area. Some habitat exists for amphibians, reptiles,
birds, and mammals.
Three Federally-listed species have been reported to occur in
Wilson County. These species are the red-cockaded woodpecker
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(Picoides borealis), Michaux' sumac (Rhus michauxii), and the
dwarf wedge mussel (Alasmidonta heterodon). All are listed as
Federally-endangered. Surveys done by the Corps in the project
area did not find the dwarf wedge mussel.
Even without the proposed flood control projects in the Hominy
Swamp watershed, the future of the existing fish and wildlife
resources would be uncertain. Increased human population and
development are likely to further degrade both aquatic and '
riparian habitats along Hominy Swamp.
Early flood control plans released in 1968 consisted of 5.1 miles
of channel improvements to be done in two sections. In the
southern section of 3.4 miles the existing channel would be
enlarged to a 35-foot bottom width with 1:1 side slopes and
unspecified deepening. In the northern section of 1.7 miles the
existing channel would be enlarged to a 30-foot bottom width with.
1:1 side-slopes and unspecified deepening.
The scale of the project currently.under consideration has been
reduced. The total project length is 2.1 miles. In the southern
section of approximately 0.9 mile, work would be limited to
clearing and snagging the existing channel. The channel in the
remaining 1.2 miles would be widened to 25 feet: A 12-foot
diameter culvert would be bored and jacked through the fill under
the CSX railroad main line to make the improved conditions
al from
the channel would be removed and transported to an upland
disposal site.
There are potential adverse environmental impacts associated with
the proposed project. Tree and shrub removal on the rights of
way and replacement with a landscaped vegetation maintained by
periodic mowing can be expected to reduce wildlife species
diversity and population densities. Channelization would reduce
allocthonous input of an important biochemical energy source.
The removal of canopy cover would increase water temperatures and
reduce the concentrations of dissolved oxygen. A reduction in
dissolved oxygen would stress aerobic, aquatic organisms. The
project could reduce water storage in the watershed and produce
harmful low flow conditions during drought periods. Reduced.
water storage could also lead to changes in plant communities in
the watershed. The project could lead to increased sediment
deposition downstream from the project area. A long term impact
of the project could be increased development in the floodplain
which would further eliminate and fragment existing, natural
plant communities. Increased development would increase
stormwater runoff which could lower water quality and increase
erosion.
The potential adverse impacts of the project could be minimized
by incorporating conservation measures into project design and
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construction techniques. Riparian revegetation may be the most
1 significant opportunity to rectify impacts. Trees planted on the
stream banks would provide wildlife habitat and much needed
i stream shading. Other conservation measure include limiting the
removal of stream side vegetation, clearing and stabilizing banks
in stages, removing all sediment to an upland disposal site,
creating and maintaining an effective sediment trap downstream
from the project area.
The Service believes that the potential adverse environmental
effects of the proposed flood control project can be avoided
and/or minimized by the use of certain design features and
construction techniques. Therefore, this report presents several
general fish and wildlife conservation measures and five
recommendations. These recommendations are:
1. In the southern part of the project area where work will be
limited to clearing and snagging, no rooted trees, alive or
dead, should be,cut unless they are leaning over the channel
at an angle greater than 20 degrees off vertical, have
severely undercut or damaged root systems, or are relying
upon adjacent vegetation for support (McConnell and Zerfoss
1982). All trees and debris removed from the project area
should be transported'to an approved upland site for
disposal.
2. All areas cleared for construction, should be landscaped in
order to provide maximum wildlife habitat and stream
shading. Mast-producing, hardwood trees, such as oaks
(Quercus spp.) and hickories (Carya spp.), spaced widely
along this stream bank would shade the stream and help
stabilize the banks without causing significant impediments
to water flow in the channel. The Corps should work with
the local sponsor to develop a maintenance program which
enhances wildlife habitat. One beneficial aspect of such a
plan would be to schedule the mowing of herbaceous
vegetation on bank areas at a minimum interval of once
during the midsummer every two years.
3. In order to minimize erosion during construction, the.
clearing and stabilization of the banks should be conducted
in stages. After each segment is cleared of all vegetation,
'it should be graded and stabilized. Each bank segment
should be stabilized prior to initiating construction on the
adjacent segment. All spoil removed from the project area
should be transported to an approved, upland site for
disposal.
4. To protect downstream aquatic habitats from sedimentation
problems caused by project construction, the sediment trap
to be created downstream of the project should be maintained
by cleaning during construction and for a specified period
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of time thereafter to allow the banks to be stabilized with
vegetation. Cleaning should be undertaken whenever the trap
become half full. This cleaning would insure that sudden
` periods of heavy rain would not cause the trap to overflow.
5. Consultation, pursuant to Section 7 of the Endangered
Species Act of 1973, as amended, should be completed, and
the Corps should assess and minimize potential adverse
effects on the Federally-listed threatened and endangered
species which may occur in the project area.

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$_ IV
TABLE OF CONTENTS
Pa e
Executive Summary . . . . . . . . . . . . . . . . . . . . . i
Table of Contents . . . . . . . . . . . . . . . . . . . ... . . V
Introduction . . . . . . . . . . . . . . . . . . . . . . . . 1
Purpose, Scope, and Authority . . . . . . . . . . • • . • 1
Prior studies . . . . . . . . . . . . . . . . . 1
Study Area Description . . . . . . . . . . . . . . . . . . . . 3
Fish and Wildlife Service Concerns and Planning Objectives 4
Evaluation Methods . . . . . . . . . . . . . . . . . . . . . . 6
Existing Fish and Wildlife Resources . . . . . . . . . . . . . 6
General Fish and Wildlife Resources . . . . . . . . . . . 6
Federally Endangered and Threatened Species . . . . . 7
Future Fish and Wildlife Resources without the Project . . . . 8
Description of Alternatives Considered 9
Selection of the Preferred Alternative 12
Potential Impacts of the Preferred Alternative . . . . . . . 13
Direct Impacts 13
Indirect Impacts . . . 15
Cumulative Impacts . . . . . . . . . . . . . . 16
Summary of Impacts . . . . . . . . . . . . . 16
Fish and Wildlife Conservation Measures 16
? 18
Recommendations •
Summary of Findings and Service Position . . . . . . 19
Literature Cited _ •' • • • . . . • 20
FIGURES
Figure 1. General location of the Hominy Swamp Flood Control 2
Project, Wilson County, North Carolina. . . . . . .
Figure 2. Project area for the Hominy Swamp Flood Control
Project, Wilson County, North Carolina. The area from
Point A (SR 1606, Black Creek Road) to Point B (trestle
of railroad spur) would be cleared and snagged. The
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channel from Point B to Point C (bridge for Goldsboro
Street) would be widen. At Point D (fill under CSX
Railroad track) a new culvert would be installed.
Source of base map: Wilmington District, U. S. Army
Corps of Engineers . . . . . . . . . . . . . . . . . 10
Figure 3. Topographic map of the Hominy Swamp Flood Control
Project, Wilson County, North Carolina. Points A-D
represent the same features as those in Figure 2. 11

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INTRODUCTION
Purpose, Scope, and Authority
The Corps of Engineers' planning for the proposed Hominy Swamp
Project, Wilson County, North Carolina, is being carried out
under general authority of Section 205 of the Flood Control Act
of 1948, as amended, (33 U.S.C. 701s). The specific study was
part of an authorization within the Senate Public Works Committee
Resolution of April 15, 1966 and House Document 175/89. This
report is submitted in accordance with provisions of the Fish and
Wildlife Coordination Act, as amended (48 Stat. 401; 16 U.S.C.
661 et, seq.). It constitutes the Service's formal report
required under Section 2(b) of that Act. The purposes of this
report are to document the proposed project's impacts on fish and
wildlife and to recommend measures to conserve fish and wildlife
resources. The contents of this report have been developed in
coordination with the North Carolina Wildlife Resources,
Commission.
The Hominy Swamp Project has been proposed to reduce flood damage
along portions of the waterway within the City of Wilson, Wilson
County, North Carolina. There has been a persistent problem of
flooding along Hominy Swamp. This problem appeared to worsen
during the 19601s. Increased flooding may have resulted from
land use changes in the basin above Wilson where cropland and
woodlands were converted to residential,' commercial, and
industrial uses. Annual floods in the project area affect
streets, parking lots, storage areas, and residential lawns and
gardens. Floods of an approximately 3-year frequency affect
houses, warehouses, industrial sites, commercial buildings, and
streets.
The purposes of this report are to document the potential impacts.
of the proposed project on fish and wildlife resources and
provides recommendations to conserve and protect these resources.
For the purpose of this report, the study area is the bed, banks,
and 100-year floodplain of Hominy Swamp from the bridge at
Goldboro Street near the center of Wilson downstream to the
Bridge at State Road 1606, Black Creek Road (Figure 1).
Prior Studies
Planning for this project has extended over many years. A
Detailed Project Report was released by the Corps on May 6, 1968.
The project was orignially linked to a similar flood control
project on Adkins Branch in Kinston, Lenoir County, North
Carolina. On March 24, 1987 a Service biologist visited the site
to assess the fish and wildlife resources in the project area.
On July 14, 1987 the Service issued a Planning Aid Report for the
combined Adkins Branch/Hominy Swamp Projects. In the early
1990s, the two projects were separated. On June 22, 1990 Corps
biologist surveyed the project area. This survey considered
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Figure 1. General location of the Hominy Swamp Flood Control
Project, Wilson County, North Carolina.
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aquatic habitats and specifically sought to determine whether. the
Federally-endangered dwarf-wedge mussel (Alasmidonta heterodon)
was present. The Hominy Swamp project has now been reactivated.
The Service received a project description for the proposed work
on May 22, 1995. The area was revisited by a Service biologist
on June 28, 1995 in order to assess fish and wildlife resources.
STUDY AREA DESCRIPTION
The Hominy Swamp study area extends from its headwaters near the
Wilson County Airport south to its confluence with Contentnea
Creek in Wilson County, North Carolina (Figure 1). The watershed
is approximately 9,500 acres in size and includes most of the
western half of the City of Wilson. For the purpose of this
report, the study area is the bed, banks, and 100-year floodplain
of Hominy Swamp.
Based on 1978 USGS mapping, land use was divided approximately
equally among urban areas, cleared and undeveloped land (mostly
agricultural), and forested areas (natural and residential).
Since 1978, urban and residential development has significantly
reduced the proportion of natural and agricultural land.
Urbanization also has adversely affected the.aquatic, riparian,
and floodplain fish and wildlife habitats of Hominy Swamp.
Previous channelization, channel clearing by the City of Wilson,
and intense, rapid urban and agricultural runoff create poor
quality aquatic habitat-conditions and low species diversity.
C. The stream bed is comprised of unstable and unconsolidated sand
and silt and is unvegetated and virtually free of snags and other
debris.. Within the project area the stream channel varies. from
approximately 20 feet to 40 feet wide with width generally
increasing from north to south.
Stream banks are generally steep, sandy, stable .or moderately
eroding, and increase in height from approximately 4 feet
upstream to approximately 8 feet. at the downstream, end of the
study area. Bank height reaches 15 feet in some locations where
spoil from previous channelization has been piled on the
floodplain. This condition is particularly. evident in the
downstream half of -the study area. The City of Wilson has no
stream bank maintenance program.
South of US 301 the banks are generally well-vegetated with
dense, riparian shrub and canopy layers which provide shading for
the stream. Palustrine forested and other floodplain wetland
" habitats exist in several areas along Hominy Swamp. The largest
area of bottomland hardwood forest exists on the floodplain south
of the study area. This forest extends downstream from Sewage
Treatment Plant No. 2 to Contentnea. Creek and becomes more narrow
upstream of the plant where it extends nearly to SR 1606. Other
naturally vegetated forested wetland areas exist between SR 1606
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and US 301, principally on the west side of the creek and on both
sides of the area between Elizabeth Road and Raleigh Road.
Except for the area south of Sewage Treatment Plant No. 2,
E....>' forested wetlands in the project area are isolated patches of
habitat within an urban setting. Most of the adjacent floodplain
and upland areas are developed.
North of US 301 the banks have few, if any, mature trees. The
banks have dense growths of shrubs, vines, small trees, and
herbaceous plants. In areas adjacent to residential property,
residents maintain the banks in short grasses.
FISH AND WILDLIFE SERVICE CONCERNS AND PLANNING OBJECTIVES
The involvement of the Service in this study is in response to a
Congressional mandate through the Fish and Wildlife Coordination
Act (op. cited) which directs that the conservation of fish and
wildlife resources shall receive full and equal consideration and
Fish and wildlife and their habitats are valuable public
resources which are conserved and managed for the people by State
and Federal governments. If proposed land or water developments
may reduce or eliminate the public benefits that are provided by
such natural resources, then State and Federal resources agencies
have a responsibility to recommend means and.measures to mitigate
policy of the service to seek to mitigate losses of fish,
wildlife, and their habitats and to provide information and
recommendations that fully support the Nation's needs for fish.
and wildlife resource conservation as well as sound economic and
social development through balanced multiple use of the Nation's
natural resources.
Nationwide, urban development of floodplains has had drastic
impacts on fish and wildlife resources (Leedy et al. 1981).
Homes, factories and businesses have been built on floodplains
with little regard for the dangers of flooding. When the
waterways inevitably overflow their banks and cause property
damage, the solution to the problem has often been stream
channelization. These efforts to "control" flooding have led to
increased downstream flooding and to the loss of riparian forests
and the conversion of natural stream beds with a diversity of
aquatic habitats to wide, flat-bottom ditches bordered by
maintained herbaceous vegetation. With better planning, however,
streams and riparian forests can be important features of a
city's plan for parks, natural areas, and open space and can
provide fish and wildlife habitats, recreation areas, and
enhanced urban aesthetic quality (Leedy et al. 1978).
The land surrounding the section of Hominy swamp under study is
being developed at a rapid rate. The development of new
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residential and commercial properties is resulting in an increase
in the amount of impermeable surfaces in the watershed and
I: associated increases in stormwater run-off. The channel has been
previously modified to enhance storm drainage of the surrounding
urban and residential lands. The creek's water quality and
availability of aquatic habitat is poor. There are currently
only limited, existing biological resources of concern. The
opportunity for enhancing aquatic habitat is limited due to the
continual development of the watershed outside of the study area.
Control of this development outside the project area is not under
the jurisdiction of the Corps, and therefore, such adverse
impacts cannot be overcome as part of this project. Aquatic
habitat and water quality of Hominy Swamp will not improve
without significant instream habitat modifications and the
initiation of a comprehensive watershed management plan directed
towards the elimination of polluted discharges and sediment.
deposition in the creek channel. However, some limited planning
opportunities do exist to ensure that the proposed project does
not produce any additional deterioration of fish and wildlife
habitats.
As the Service stated in our Planning Aid Report of July 14,
1987,.-the Hominy Swamp watershed offers opportunities for
implementing fish and wildlife habitat conservation, restoration,
and enhancement measures. Attainment of these goals is possible-
if they are adequately, addressed in the,planning process. The
planning objectives of the Service for this project include these
items:
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1. Restoration of water quality through local control of
effluent discharge and stormwater runoff from contaminated
sources such as roads and parking lots.
2. Reduction of stream bed siltation through control*of upland
stream bank erosion.
3. Reduction of stormwater discharge intensity by installing
retention facilities for impervious surfaces of significant
area.
4. Revegetation of cleared stream banks with trees and shrubs
for bank stabilization, stream shading, and riparian
wildlife habitat enhancement.
5. Enhancement of aquatic habitat quality by providing
structures for habitat diversity and water-aeration.
6. Development of an urban greenway system along Hominy Swamp
by permanently protecting existing natural areas and
connecting them with revegetated and permanently protected
riparian habitat corridors.
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7. Avoidance of all discharges of fill in wetlands.
8. Restoration of floodplain hydrologic connections between
Hominy Swamp and its lower reaches by removing relict piles
of discharged dredged material.
In accordance with the Fish and Wildlife Coordination Act, as
amended, these planning objectives should be given full and equal
consideration with other features of the Hominy Swamp Project.
EVALUATION METHODS
Descriptions of anticipated impacts to fish and wildlife
resources are derived from previous studies on this and other
projects, published literature, personal communications with
other biologists and planners, and qualitative information
obtained.during site visits by Service and Corps biologists.
Plant nomenclature follows Radford et al. (1968); fish
nomenclature follows Rohde et al. (1994); bird nomenclature
follows Potter et al. (1980); and mammal nomenclature follows
Webster et al. (1985).
General Fish and Wildlife Resources
The project area is impacted to various degrees by development
within the City of Wilson. The northern part of the area (north
of US 301) has been highly altered by this development. While
the southern part shows less direct impact, any alterations of
water quality flow into this area would affect the habitat value
of the area. Within the entire area there is limited
availability and diversity of structural habitat components.
Aquatic organisms probably.suffer physical stress from intense
flushing caused by stormwater runoff. Biochemical stress of
reduced levels of dissolved oxygen due to solar exposure and
inadequate natural-water aeration further exacerbate this
condition.
Hominy Swamp does provide limited support for adaptable
invertebrates. A survey by Corps biologist in 1990.found three
species of gastropods, but no bivalves were found. The Corps
report noted that the stream was severely degraded, a condition
resulting from past channelizations, severe sedimentation, and,
probably, poor water quality. The species were pewter physa
(Physella heterostropha), creeping ancylid (Perrissia rivularis),
and bugle sprite (Menetus dilitatus). These species are
pollution tolerant organisms and have been noted to occur in
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survey in the project area on June 22, 1990.

%-? disturbed or degraded waters. A Service biologist noted several
crayfish towers on the floodplain during the site inspection in
June 1995.
The presence of some vegetation and a limited invertebrate fauna
suggest that Hominy Swamp can support some vertebrate species.
Fish surveys were conducted in the project area on May 1, 1987.
These surveys found the eastern mosquitofish (Gambusia
holbrooki), pumpkinseed (Lepomis gibbosus), warmouth (Lepomis
gulosus), bluegill (Lepomis macrochirus), green sunfish (Lepomis
cyancellus), and the American eel (Anguilla rostrata). one
unidentified fish approximately five to six inches long was
observed in Hominy Swamp at its intersect with Phillips Street
during the site visit in June 1995.
The project site probably provides habitat for a limited number
of amphibians and reptiles. The riparian woodlands in the.
southern section appear suitable for species of frogs, toads,
salamanders, and snakes which are adapted to disturbed habitats.
Habitat for birds varies greatly between the northern and
southern sections of the project area. The wooded riparian areas
of.the southern section probably supports a wider diversity of
birds than the open, cleared areas of the northern section.
Birds noted by Service biologists in the southern section include
the Carolina chickadee (Pares carolinensis), red-tailed hawk
(Buteo jamaicensis), common crow (Corvus brachyrhynchos). This
section probably provides habitat for birds adapted to isolated
woodlands such as woodpeckers and flycatchers. The northern
section may support open area birds such as the sparrows, eastern
meadowlark (Sturnella magna), and red-winged blackbird (Agelaius
phoeniceus).
The existing mammalian fauna is probably limited. The area may
provide habitat for a diversity of rodents and disturbed area
species such as the opossum (Didelphis virginla), gray squirrel
(Sciurus carolinensis), and raccoon (Procyon"Iotor). Data from
site visits have included the observation of the eastern
cottontail rabbit (Sylvilagus floridanus) and raccoon tracks.
Federally Endangered and Threatened Species
Service data for Wilson County indicate that three Federally-
listed species may occur in the county. These species are the
red-cockaded woodpecker (Picoides borealis), Michaux' sumac (Rhus
michauxii), and the dwarf wedge mussel (Alasmidonta heterodon).
All are listed as Federally-endangered.
The red-cockaded woodpecker (RCW) nests in old growth pine stands
in which understory.development has been suppressed. From the
nesting area birds may forage in stands of pine or pine-hardwoods
which are at least 30 years old. Service biologist have not
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reported suitable habitat for this species. However, the Corps
must collect all data necessary to reach a determination of the
impacts of the project on this species.
Michaux's sumac is a densely hairy shrub with erect stems which
are one to three feet in height. The species grows in.sanidy or
rocky open woods in association with basic soils. The best
survival of the plant appears to be in areas of some form of
disturbance has provided an open area. The Corps must also
collect all necessary'to determine the impact of the proposed
project on this species.
The Corps performed field surveys for the dwarf wedge mussel in
the project area during June 1990. These surveys did not find
the dwarf wedge mussel or any other native bivalve. After
considering any factors which may have allowed the dwarf wedge
mussel to colonize the area during the past .5 years, the Corps
needed data into the environmental documentation
and their Section 7 determination required under
Species Act, as amended (op. cited).
for the project
the Endangered
FUTURE FISH AND WILDLIFE RESOURCES WITHOUT PROJECT
Rxmn ors host he proposed flood control. projects in the Hominy
Swamp watershed, e u ure
resources would be uncertain. Projected human population growth
rates for Wilson Counties-for the period 1980-2030 is 47.7
percent (U. S. Army Corps of Engineers 1984). The remaining
agricultural and forested uplands will be under increasing
development pressure. Further development of uplands for
residential, commercial, and industrial use may exacerbate
problems associated with stormwater runoff and water quality.
Continuing stream bed siltation and stream bank.erosion may
perpetuate reduced aquatic habitat quality. \The development of
riparian and floodplain areas, if not locally regulated,,. is
expected to contribute to the elimination and fragmentation of
fish and wildlife habitat. The elimination of remaining natural
areas and the associated habitat fragmentation can be expected to
reduce resident wildlife populations and diminish habitat quality
for migratory'species.
On the other hand, development by environmentally conscious
developers, along with local habitat protection efforts by the
affected municipalities and residents could significantly restore
and enhance fish and wildlife habitats in the watershed. Water
quality restoration and protection, stormwater retention, erosion
control, environmentally-acceptable stream bed and bank
stabilization, vegetation establishment, greenways, and natural
area protection could improve the quantity and quality of
project-area fish and wildlife habitats.
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138
DESCRIPTIONS OF ALTERNATIVES CONSIDERED
The flood control project for Hominy Swamp has been under
consideration for many years. Early planning apparently was
conducted prior to 1968. The Corps issued a Detailed Project
Report on May 6 1968. This report states that early
consideration was given a variety of projects such as a'flood
storage reservoir, dike protection, floodproofing, and
channelization. The document concludes that the best flood
control plan consisted of 5.1 miles of channel improvements to be
done in two sections. A project area map provided by the Corps
is given in Figure 2. A topographic map of the project is given
in Figure 3. In the first section the existing channel would be
enlarged and deepened to a 35-foot bottom width with 1:1 side
slopes from a point 800 feet below the sewage outfall canal at
Sewage Disposal Plant No. 2 (lower right corner of Figure 3) to
Park Avenue (upper center of Figure 3), a distance of 3.4 miles.
In the second section the existing channel would be enlarged and
slightly deepened to'-a 30-foot bottom width with 1:1 side slopes
from Park Avenue upstream to the confluence of Big Hominy Swamp
and Little Hominy Swamp (upper left of Figure 2), a distance of
1.7 miles. The project would add a 12-foot culvert at the
Seaboard Coast Line Railroad crossing (Point D, Figures 2 and 3),
replace the existing structure at Phillips Street with a 35-foot
clear-span bridge, widen the existing bridge at Kincaid Street, .
lower four sanitary/sewer crossings, and modify one sanitary
sewer crossing. The 1968 plan also called for augmenting the
channel improvement project with floodplain regulations
t prohibiting buildings below the 100-year improved floodplain, an
action that could have been expected to significantly reduce the
potential for flooding over the long-term.
A status report of Corps activities issued on February 1, 1977,
noted that the Hominy Swamp Project still consisted of a.5.1-mile
urban channelization project. This report also notes that
several actions required completion before the Hominy Swamp
Project could be constructed. These actions-Ancluded: (1) new
assurance of cooperation from the local sponsor, the City of
Wilson; (2) floodway delineations along the project reach; (3)
preparation of an environmental statement; (4) a survey.of the
project right-of-w4y; and, (5) revise outmoded portions of
project specifications.
A status report from the Corps dated October 5, 1993 states that
the Hominy Swamp Project involves work along approximately 5
miles of the stream, but notes that ". . . the length recommended
` for improvement will probably be much less." Plans for improved
channel widths ranged from 25 to 40 feet. The report indicates.
that a description of the recommended plan would be available
shortly.
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Figure 2. Project area for the Hominy Swamp Flood Control
Project, Wilson County, North Carolina.' The area from Point A
(SR 1606, Black Creek Road) to Point B (trestle of railroad spur)
would be cleared and snagged. The channel from.Point B to Point
C (bridge for Goldsboro Street) would be widen. At Point D (fill
under CSX Railroad track) a new culvert would be installed.
Source of base map: Wilmington District, U. S. Army Corps of
Engineers.
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Sewage ?i< Sal •
Figure 3. Topographic map of the Hominy Swamp Flood Control.
Project, Wilson County, North Carolina. Points A-D represent the
same features as those in Figure 2.
11

r1 SELECTION OF THE PREFERRED ALTERNATIVE
1
On May 22, 1995 the Service received a copy of the revised
project description for the Hominy Swamp Flood Control Project.
The revised plan is smaller in scope than earlier proposals. The
current plan has considered benefit-cost analyses (John.Baden,
Corps of Engineers, personal communication, June 28, 1995).
The preferred alternative consists of various channel
improvements over approximately 2.1 miles. The downstream
project boundary would be the bridge at Black Creek Road, SR 1606 ,
(Point A, Figures 2 and 3). From this point clearing and
snagging would extend upstream for approximately 0.9 mile to the
trestle on the railroad spur* lne_ (Point B, Figures 2 and 3).
From the trestle, the channel would be widened to 25 feet for a
distance of 1.2 miles upstream to the bridge at Goldsboro Street
(Point C, Figures 2 and 3). A 12-foot diameter culvert would be
Jacked through the, fill under the-CSX railroad main
line (Putsit D, Fig=69 2 and ke Ube
continuous.
Clearing and snagging would consist of removing debris and
cutting. of saplings and underbrush, with a view toward
maintaining the stability of the banks. Large trees would not be
cut unless they are leaning and in danger of falling into the
channel, and thus becoming debris. Channel widening would
would be a deepening of 1 foot to 1.5 feet of the channel bottom
over a reach of approximately 300 feet to provide a continuous
slope for the stream bottom. The location of this reach is from
Ralston Street, the street immediately north of the railroad spur
trestle (Point B, Figures 2 and 3), to approximately 200 feet
below the trestle. In other parts of the project area minor
areas of sediment accumulation would be removed to create a
relatively flat stream channel. Side slopes would be 1H:1V.
Approximately 40,000 cubic yards would be removed and transported
to a disposal area.
Project construction would generally be limited to one bank at
any particular point, with the working bank alternating from side
to side to minimize impacts to existing features along the
stream. Excavation of both banks would be necessary in
transition areas where the channel improvement switches for one
bank to the other, and in any, areas where slopes need dressing
for stability. Slope and stream bottom protection would be
required immediately downstream of the railroad culvert where
velocities would otherwise result in erosion. A concrete apron
would extend approximately 5 feet from the outlets of the
existing culvert and the new culvert. Riprap would extend
approximately 15 feet from the end of the concrete apron. From
that point, riprap would only be needed on the slopes and would
12
IF -17-
extend another 30 feet. A total volume of about 150 cubic yards
of riprap would be needed.
In general, a 30-foot wide right of way would extend from the top
of the improved bank on either side of the stream. The right of
way would be narrower at any location where existing structures
are less than 30 feet from the improved top of bank. Rights-of-
way would be used for project construction, maintenance access,
and for landscaping measures. Rights-of-way would be cleared as
needed to facilitate construction.
A sediment trap would be provided near the downstream end of the
channel widening. This trap would serve to prevent increased
sediment resulting from the construction activities from being
carried downstream. The trap would consist of a deepened area
within the stream bottom; no riprap or outlet structures are
planned. Dimensions of the* sediment trap and construction
details will be determined during development of plans and
specifications.
All maintenance on the project would be performed by the City of
Wilson. Maintenance of right-of-way corridors in the channel
widening portion would likely consist of mowing at regular
intervals. In the area that is to be cleared and snagged,
maintenance would consist of cutting back and removing shoots ,
from the stumps that would remain after initial clearing. In all
areas, any bank erosidn would need repair and snags that fall
into the stream or wash.in from upstream would be removed.
Sediment collecting in the sediment trap would need to be removed
until the upstream banks stabilize.
Several upland disposal areas are under consideration. One area
is near the junction of Raleigh Street and Trinity. The sediment
from Hominy Swamp would be placed on trucks and hauled to the
disposal site selected.
POTENTIAL IMPACTS OF THE PREFERRED 'ALTERNATIVE
Direct Impacts
Environmental impacts of stream channelization are described in
detail by Simpson it al. '(1982), Maki et al. (1980), Marzolf
(1978), and Keunzler, et al. (1977). The most significant direct
impacts of the proposed project and the subsequent landscaping
plan would be the loss of riparian vegetation and the degradation
of instream aquatic habitats in the project area and downstream.
Terrestrial and semi-aquatic wildlife species can be expected to
suffer some adverse impacts from channelization. Invertebrate-
rich leaf packs and dense riparian vegetation on stream banks
normally provide feeding, resting and nesting habitats for toads,
13
13 -i3
s
frogs, salamanders, snakes, songbirds, shore birds, moles.,
i shrews, rodents, and furbearers.
Tree and shrub removal on the rights-of-way and replacement with
a landscaped vegetation maintained by periodic mowing can be
expected to reduce wildlife species diversity and population
densities (Simpson et al. 1982). Natural riparian vegetation
provides a variety of bird habitat components needed for
perching, roosting, feeding, breeding, and nesting sites. Some
birds, such as the kingfisher, and the herons use riparian areas
heavily; others, such as many of the songbirds, use these areas
during only part of the day, as watering sites, for example, or
only during seasonal migrations. Habitat alterations during
construction could cause a decrease in bird species diversity in
the area.. Reduction in canopy cover generally would lower the
habitat value of the area for some birds.
Channelization would reduce allocthonous input of an important '
•
which is mostly leaves and stems of tree and shrub. The
microflora which invades the coarse particulate organic matter
are food for a variety of macroinvertebrates, which, in turn,
support higher trophic levels (Marzolf 1978, Simpson et al.
1982). Channel widening also would reduce sources of tree limbs,
trunks, and root masses which are important organic inputs as
well as structural components of stream habitats.
When bank clearing and channel widening results in a more open
E. canopy, more sunlight reaches the stream. Increased solar
exposure usually results in higher water temperatures. Warmer
water will have lower dissolved oxygen concentrations than cooler
water in a shaded stream. Reduced dissolved oxygen make a stream
less habitable for aerobic macronivertebrates (Simpson et al.
1982). Increased solar exposure can exaggerate diurnal dissolved
oxygen extremes by increasing diurnal photosynthesis and
nocturnal algal respiration. Nocturnal oxyg?_n deficits caused by
algal respiration can stress aerobic organisms (Simpson et al.
1982), with adverse impacts throughout the aquatic food chain.
Channelization, and the resulting drainage of riparian and
floodplain areas, reduces water storage and may result in the
lowering of the water table. This, in turn, affects the recharge
of streams and may result in significant reduction of instream
flow during drought periods. -Fish and wildlife communities along
the waterway would be adversely affected by any significant, in-
stream water shortages.
Lowered water tables in riparian and floodplain areas and the
resultant reduced stream flow during drought periods may also
result in further impairment of water quality. Municipal and
industrial waste discharges may be more concentrated in low flow
periods and adversely affect the aquatic ecosystem directly
14
through toxic concentration of wastes an/or indirectly thorough
disruptions to algal production and aquatic respiration.
Erosion and sedimentation are among the most severe effects of
channelization. Erosion typically is caused by the interaction
of vegetation removal and channel straightening. Vegetation
removal renders the banks unstable and vulnerable to increased
stream flow velocities and rainwater (Simpson at al. 1982).
Channel straightening increases stream flow velocities and the
stream's sediment carrying capacity.
Indirect Impacts
The area in which fish and wildlife resources are affected by
stream bank clearing and channelization usually extends upstream,
downstream, and lateral from the project area. Impacts result
primarily from disruptions of hydrologic regimes. The increased
efficiency with which a cleared, wider channel drains its
watershed causes floodplain dewatering. With dewatering, wetland
and floodplain vegetation can be expected to shift slowly in
species composition from flood-tolerant, hydric plants to flood-
intolerant, mesic plant species (Maki at al. 1980, Simpson at al.
1982). A reduction in biomass production of floodplain
vegetation can also be expected (Simpson at al..1982). With such
changes in vegetation, changes in the wildlife habitat value of
an area normally follow. A less productive, mesic environment
probably would provide lower quality wildlife habitat than
riparian and floodplain forests with normal hydroperiods.
Stream bank clearing and channelization also may cause adverse
impacts on aquatic resources downstream of the project area. The
impacts of stream bed sedimentation described above may be
particularly severe immediately downstream of the channelized
section. The unaltered stream bed with a natural, sinuous course
has areas of low velocity flows where the heavy sediment loads
acquired upstream could settle out, accumulate.over time, and
ultimately smother existing, benthic communities.
Indirect adverse impacts to'fish and wildlife resources also may
occur as a result of land use changes which normally follow.
successfully dewatered floodplains. The feasibility of
floodplain development would be enhanced by any reduction in the
frequency, magnitude, or duration of floods along Hominy Swamp.
Rapid runoffs from developed land would exacerbate instream
erosion, sedimentation, and flood problems locally and
downstream. Public and private interest in further flood control
measures could follow and eventually be used to justify more
costly projects.
25
R-15-
Cumulative ImDacts
Cumulative impacts of flood control projects are described best
in terms of state, regional, and national rates of alteration of
riverine and palustrine forested wetlands. In the southeastern
U.S., few areas of bottomland hardwoods have escaped the impact
of man (Wharton et al. 1982). From 1960-1975 southeastern
bottomland hardwoods were converted at the estimated rate of
432,000 acres per year for a net loss of 6.4 million acres, or 20
percent of the total bottomlands (Mitsch and Gosselink 1986).
Nationwide, approximately 70 percent of the original floodplain
forest has been converted to other land uses (Brinson et al.
1981). About 60 percent of this countryls major stream segments
have been significantly altered.by water resource or other
cultural developments (Brinson et al. 1981). The direct and
indirect adverse impacts described previously in this report
continue to occur on state, regional, and national scales. The
?mroposed project would add to those losses.
Summary of Impacts
The potential impacts associated with the proposed project could
alter and somewhat degraded fish and wildlife habitats both
within the project area and downstream. The most significant
adverse impacts would be the loss of natural riparian vegetation,
removal of natural substrate and increased sedimentation during
FISH AND WILDLIFE CONSERVATION MEASURES
Fish and wildlife resources in the Hominy Swamp study area could
benefit from conservation measures incorporated into an effective
flood control project. Fish and wildlife conservation measures
as specified in the Fish and Wildlife Coordination Act consist of
"means and measures that should be adopted to prevent the loss of
or damage to such wildlife resources (mitigation), as well as to
provide concurrently for the development and-, improvement, of such
resources (enhancement)." Mitigation, as defined by the Council
on Environmental Quality and adopted by the* Service in its
Mitigation Policy, includes:
1) avoiding the impact altogether by not taking a certain
action or parts of an action;
2) minimizing impacts by limiting the degree or magnitude
of the action and its implementation;
3) rectifying the impact by repairing, rehabilitating, or
restoring the affected environment;
16
[3,16
4) reducing or eliminating the
preservation and maintenance
of the action; and
impact over time by
operations during the life
5) compensating for the impact by replacing or providing
substitute resources or environments.
These five actions should be viewed as the proper sequence for
formulating conservation measures.
Enhancement measures are those which result in a net increase in
resource values under the with-project condition compared to the
without-project condition. For any given type, kind, or category
of resource being evaluated, all project-associated losses must
first be compensated, i.e. fully replaced, before any enhancement
of that given resource can occur.
Minimization of project length, alternating the working bank, and
removal of all dredge spoil will do much. to mitigate project
related impacts on fish and wildlife. However, additional
mitigative measures are possible.
Riparian revegetation may be the most significant opportunity to
rectify impacts. Trees planted on the stream banks would provide
wildlife habitat and critical shading of the stream. Hardwood, .
mast-producing trees spaced widely along stream banks would shade
the stream and help stabilize the banks'without causing
significant impediments to water flow in the channel.
l
The habitat benefits of stream side area will be influenced by
any landscape plan. In areas not designated for public use, the
benefits of planting herbs and shrub to wildlife will generally
be proportional to the height and density of the vegetation.
Birds, small mammals, reptiles and amphibians will find areas
much more habitable if the areas are mowed less frequently than
twice-a-year. spring mowing would eliminate, many wildlife
breeding and nesting opportunities. Fall mowing would destroy
important cover and foraging habitat for overwintering wildlife.
A single, midsummer mowing every other year would greatly
increase wildlife value of the areas without significant
impairment of the ehannel's drainage capacity.
Channelization will increase stream flow velocities and,
therefore, sediment transport and may exacerbate stream bank
erosion problems. Stream bed and bank disturbance by
construction of the proposed project may itself cause a
significant increase in the sediment load in the project area and
downstream. Every opportunity should be taken to minimize these
problems and to prevent the project from increasing erosion and
sedimentation problems over the long term. Measures which should
be considered include the use of sediment traps. Upstream traps
could offset sediment problems caused by the project.and improve
17
13 r/7
S
I;
the aquatic habitat recovery potential. Downstream traps could
protect downstream areas from increased sedimentation problems
resulting from the project construction and from long term
increases in sediment flushed from the project area. Such
controls could result in significantly more stable aquatic
habitats with benefits to fish and aquatic and semiaquatic
wildlife.
RECOMMENDATIONS
The Service recommends that the following fish and wildlife
conservation measures be incorporated into Hominy Swamp flood
control project:
1.
In the southern part
limited to clearing
dead, should be cut
at an angle-greater
art of the project area where work will be
and snagging, no rooted trees, alive or
unless they are leaning over the channel
than 20-degrees off_vertical,_ have
2.
3.
upon adjacent vegetation for support
1982). All trees and debris removed
should be transported to an approved
disposal.
from the project area
upland site for
All areas cleared for construction should be landscaped in
order to provide maximum wildlife habitat and stream
(Quercus spp.) and hickories (Carya spp.), space widely
along this stream bank would shade the stream and help
stabilize the banks without causing significant impediments
to water flow in the channel. The Corps should work with
the local sponsor to develop a maintenance program which
enhances wildlife habitat. One beneficial aspect of such a
plan would be to schedule the mowing of herbaceous
vegetation on bank areas at a minimum interval of once
during the midsummer every two years.
In order to minimize erosion during construction, the
clearing and stabilization of the banks should be conducted
in stages. After each segment is cleared of all vegetation,
it should be graded and stabilized. Each bank segment
should be stabilized prior to initiating construction on the
adjacent segment. All spoil removed from the project area
should be transported to.an approved, upland site for
disposal.
4. To protect downstream aquatic habitats from sedimentation
problems caused by project construction, the sediment trap
to be created downstream of the project should be maintained
by cleaning during construction and for a specified period
of time thereafter to allow the banks to be stabilized with
vegetation. Cleaning should be undertaken whenever the trap
t3'?S
O
become half full. This cleaning would insure that sudden
periods of heavy rain would not cause the trap to overflow.
5. Consultation, pursuant to Section 7 of the Endangered
Species Act of 1973, as amended, should be completed, and
the Corps should assess and minimize potential adverse
effects on the Federally-listed threatened and endangered
species which may occur in the project area.
SIIMMRY OF FINDINGS AND SERVICE POSITION
Coastal plain streams and the associated woodlands, such as the
project area at Hominy swamp, may serve as important fish and
wildlife habitat. Habitats in and adjacent to Hominy Swamp
include the stream itself and naturally vegetated riparian areas.
In the undisturbed state, these areas provide habitat for a
variety of fish and wildlife species. However, fish and wildlife.
habitat has been degraded by and lost to previous stream
channelization and urban development. At the present time both
aquatic and terrestrial habitats in the project area are below
optimum quality, and significant opportunities exist for
enhancement. The stream carries a sediment load eroded from
construction sites, agricultural activities, and other land
disturbing activities. The stream is also adversely affected by
urban stormwater runoff, which physically and chemically stresses
the instream biota., While naturally vegetated riparian and
floodplain areas are fragmented by urban development into small
habitat patches., these patches still provide valuable wildlife
habitat.
Future human population development is likely to exacerbate
aquatic and wetland habitat degradation and loss unless
aggressive plans are implemented for natural resource
conservation, restoration, and enhancement. The Corps'
recommended plan for controlling flooding along the segment of
Hominy Swamp in Wilson should not cause significant, further .
degradation in the quality of the fish and wildlife habitat in
the project area. The most noticeable impacts of this flood
control project would be the loss of riparian vegetation and
construction-related sedimentation.
The Service believes that the potential adverse effects of the
proposed project can be significantly reduced by implementation
of the recommendations for fish and wildlife conservation
described in this report. Details for the implementation of the
recommended measures should be coordinated among representatives
of the Corps, the City of Wilson, the North Carolina Wildlife
Resources Commission, and the Service.
19
13 - /,,?
APPENDIX C
Hydrology and Hydraulic Analysis
APPENDIX C
HYDROLOGY AND HYDRAULICS ANALYSIS
TABLE OF CONTENTS
Item Page No.
INTRODUCTION
Purpose C-1
BASIN DESCRIPTION
Location C-1
Topography C-1
Land Use C-2
Stream Gage Network C-2
Climatology C-2
Precipitation C-3
Historical Floods C-3
PEAK DISCHARGE FREQUENCY EVALUATIONS
General C-3
Stream Flow Data C-3
USGS Sfudy C-3
Adopted Peak Discharge Frequency Curves C-4
FLOOD ROUTING MODEL
General C-4
Routing Model C-4
Routing Method C-4
Unit Hydrographs C-5
Watershed Characteristics C-5
Soil Characteristics C-5
Runoff Curve Numbers C-5
Lag Time C-5
DESIGN STORMS
Hypothetical Storms C-6
Standard Project Storm C-6
DESIGN FLOOD HYDROGRAPHS
Hypothetical Floods C-7
Standard Project Flood C-7
i
TABLE OF CONTENTS - Cont'd
Item Page No.
WATER SURFACE PROFILES
General
Physical Data
Discharge vs. Drainage Area
Water Surface Profiles for Existing Conditions
C-7
C-7
C-8
C-8
CHANNEL IMPROVEMENT EVALUATIONS
Structural Alternatives C-g
Recommended Channel Design C-8
Water Surface Profiles for Improved Conditions C-8
ReAdsad beak Discharges C -R
PROJECT IMPACTS
Stage Reductions C-9
Downstream Impacts C-10
CHANNEL PROTECTION MEASURES
Channel Protection Criteria C-10
Open Channel Velocities C-10
Bridge Velocities C-10
Riprap Design C-11
LIST OF TABLES
Table No. Title
C-1 Hominy Swamp Drainage Areas
C-2 Stream Gaging Station Data
C-3 Average Monthly Temperatures
C-4 Average Monthly Rainfall
C-5 Unit Hydrograph Parameters
C-6 24-Hour Rainfall (TP-40)
C-7 Standard Project Storm Data
C-8 Existing and Improved Water Surface Elevations
C-9 Channel Velocities - Existing and Improved
C-10 Bridge Velocities - Existing and Improved
C-11 Bridge Riprap Parameters
Page No.
C-1
C-2
C-2
C-3
C-6
C-6
C-7
C-9
C-10
C-11
C-13
ii
TABLE OF CONTENTS - Cont'd
LIST OF PLATES
Plate No. Title
C-1 Study Area
C-2 Peak Discharge Frequency Curve
C-3 Peak Discharge Frequency Curve
C-4 Peak Discharge Frequency Curve
C-5 Discharge Versus Drainage Area Curves
C-6 Water Surface Profiles
iii
APPENDIX C
HYDROLOGY AND HYDRAULICS ANALYSIS
INTRODUCTION
P=ose. This appendix presents the results of the hydrology and hydraulics
investigations made in support of the Hominy Swamp 205 study. The hydrology and
hydraulics analysis deals with the investigations necessary to support channel
improvements to Hominy Swamp for the purpose of flood reduction. As shown on Plate
C-1, the study limits begin at the confluence of Hominy Swamp and Contentnea Creek
and extends upstream to the confluence of Hominy Swamp and Little Hominy Swamp
above Kincaid Avenue. Numerous alternatives for reducing flood damage through the
City of Wilson were investigated during the study. Hydrology and Hydraulics
riommy swamp. l he recommended project consists of two components. The first
component is the addition of a 12 feet diameter conduit through the Seaboard Coastline
Railroad fill just above U.S. Highway 301 bridge. The second component consists of
modifying the stream channel from Black Creek Road to Goldsboro Street.
BASIN DESCRIPTION
Location. Hominy Swamp is located in the coastal plain region of North Carolina in
Wilson County. It is a tributary of Contentnea Creek and drains and area of
approximately 15.7 sq. mi. The headwaters of Hominy Swamp begin Northwest of
Wilson near the airport. The stream flows generally south through the center of Wilson
and enters Contentnea Creek South of Wilson. Table C-1 gives drainage areas at various
locations along Hominy Swamp.
Table C-1
Hominy Swamp Drainage Areas
Location Miles above Mouth Drainage Area
(sq. mi.)
Mouth 0.0 15.7
Black Creek Road 3.2 9.7
U.S. Hwy 301 Bridge 4.3 7.9
Goldsboro Street 5.2 7.4
Raleigh Road 6.5 5.3
Topography. The topography of Hominy Swamp is typical of streams in the Coastal
Plain Region of North Carolina. The lower 2.5 miles of the stream has low, wide
overbanks which are typical of a coastal swamp. The remainder of the stream is
characterized by gradual stream gradients and wide flat flood plains.
Land Use. The Hominy Swamp watershed is typical of small streams in urban areas of
North Carolina. The land use varies from rural farmland to highly developed urban areas.
The lower portion of the stream as described above is swampy and the flood plain is
largely undeveloped. The land use in the middle reaches of the stream, which flows
through the center of the Town, is mainly commercial and industrial development and
some high density residential development. The development is typical of older
communities with development up to the top of the stream bank and in the flood plain.
The upper portion of the basin, is undergoing a change from open farmland and forest use
to residential development.
Stream Gaging Network. There are no stream gages in the Hominy Swamp watershed.
There are gages in adjacent basins which have similar sized drainage areas and similar
hydrologic characteristics. Table C-2 gives pertinent data on these gages.
USGS Yrs. Drainage Avg. Max Min
Sta. of Area Flow Flow Flow
No. Stream Name and Location Rec. (sq. mi.) (cfs) (cfs) (cfs)
90512 Hominy Swamp at Wilson, NC 7 7.9 8.3 943 0.0
92000 Swift Creek nr. Vanceboro, NC 35 182 201.0 6060 0.0
91960 Creeping Swamp Nr Calico, NC 14 9.8 35.7 1810 0.0
91700 Little Contentnea Crk nr Farmville 29 93.3 117.0 5170 0.0
8500 Rockfish Creek nr Wallace, NC 27 69.3 94.8 5540 0.4
92020 Palmetto Creek nr Vanceboro, NC 24 24.0 26.6 3700 0.0
7590 NE Cape Fear Trib nr Mt. Olive 18 0.6 118 0.0
7600 NE Cape Fear Rr nr Seven Springs 17 47.5 63.3 2740 3.0
90625 Turner Swamp nr. Eureka, NC 17 2.1 2.3 652 0.1
91000 Nahunta Swamp nr. Shine, NC 31 80.4 86.1 5470 1.0
Climatology. The climate of the Hominy Swamp Basin is characterized by warm
summers and usually mild winters. Average maximum and minimum monthly
temperatures are shown in Table C-3.
Table C-2
Stream Gaging Station Data
Table C-3
0
Average Monthly Temperatures
Jan Feb Mar
Max 52.6 55.1 63.8
Min 31.2 32.3 40.6
Mean 41.9 43.7 52.2
(Degrees, Fahrenheit)
Apr May Jun Jul Aug
74.0 80.4 86.8 89.7 88.8
47.7 56.6 63.8 68.2 67.5
60.8 68.5 75.3 78.9 78.1
Sep Oct Nov Dec
83.5 73.7 64.0 56.0
61.1 49.1 38.9 34.2
72.3 61.4 51.4 45.1
Mean Annual Maximum Temperature
Mean Annual Minimum Temperature
72.9
50.1
C-2
Precipitation. The Hominy Swamp Basin and the surrounding area normally receives
abundant rainfall. U.S. Weather Service records at Wilson show that Wilson receives an
average annual rainfall of approximately 46.3 inches. The rainfall is generally well
distributed throughout the year as shown in table c-4, with the greater amounts generally
falling during the summer months.
Table C-4
Average Monthly Rainfall
(Inches)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Max 7.75 6.97 7.47 7.64 8.23 12.0 18.7 14.2 11.6 8.00 7.85 7.27
Min 3.69 3.64 4.05 3.15 3.87 3.98 5.69 5.15 4.01 2.65 3.08 3.34
Mean 1. -3 R- 0-6-9 093 0-52 1-96 0 40 1-45 0.83 0.17 0.21 0.44 0.60

Annual Maximum Rainfall 62.73
Annual Mean Rainfall 46.30
Annual Minimum Rainfall 30.58
Historical Floods. Damaging floods have been reported to have occurred in the
u,.m;.,., C?aamn Racin
PEAK DISCHARGE FREQUENCY EVALUATIONS
General. Peak discharge frequency evaluations for Hominy Swamp for existing
conditions were performed in accordance with U.S. Water Resource Council (WRC)
Bulletin 17B, "Guidelines for Determining Flood Flow Frequency" dated 1982.
Supporting evaluations were performed using the U.S. Geological Survey (USGS) Water
Resources Investigations Report 87-4096, "Magnitude and Frequency of Floods in Rural
and Urban Basins of North Carolina". The impact of recommended channel
improvements on peak discharge frequency curves are discussed later.
Stream Flow Data. There are currently no streamflow gages on Hominy Swamp.
Several stream gages are located in adjacent basins with similar streamflow
characteristics. While Hominy Swamp is an urbanized basin all of the streamflow data
available on streams with similar topographic characteristics and drainage areas are still
rural. It was therefore necessary to adjust the frequency data determined for the adjacent
streams to account for urbanization using methods described in the publication referenced
above.
USGS Study. The USGS study referenced above used the Pearson Type III distribution
of annual maximum discharges to define station flood frequency distributions in
accordance with methods in WRC Bulletin 17B. Frequency statistics were developed for
rural and urban basins in the state. Peak discharges for selected recurrence intervals were
C-3
the computed, using methods in Bulletin 17B, as a basis for developing regional flood
relationships using multiple linear-regression analysis to relate flood discharges to
selected recurrence intervals. Equations for various frequency events were developed for
regions of the State based on similar topographic and hydraulic characteristics. These
equations were based on rural undeveloped basins in the region. Using relationships
developed earlier for other parts of the Southeastern United States, peak discharge
relationships were developed for urban basins in the region. These equations were tested
and determined to apply to streams in North Carolina. The application of these equations
first requires an estimate of peak frequency discharges based on rural or undeveloped
conditions. The discharges are then adjusted to represent development or urbanization
based on the amount of development and imperviousness in the drainage basin.
In previous studies of similar streams in the coastal plain region of North Carolina,
comparisons were made of the results utilizing regionalized frequency statistics from
gages in the area which were similar, although not developed, to determine if the USGS
equations were appropriate to use. The frequency curves developed using the USGS
equations for rural basins agreed with those developed using statistics form gage records.
Because of this close comparison, it was felt that the USGS curves when adjusted for
urbanization, accurately reflect conditions on Hominy Swamp.
Adopted Peak Discharge Freguency Curves. Since the Hominy Swamp Basin is
urbanized, it was necessary to apply the appropriate adjustment factors described in the
USGS publication to the equations in order to account for development. Plates C-2
through C-4 show the adopted frequency curves after accounting for the impacts of
urbanization and development.
FLOOD ROUTING MODEL
General. The railroad fill above US Highway 301 creates ponding upstream of the fill
during high order flood events. It was necessary to route flood discharges through the
culvert and downstream to the end of the study reach in order to determine peak
discharges downstream of the culvert and to determine the impacts oradding the
additional culvert to the railroad fill. A routing model was also necessary to determine
the effect of loss valley storage on peak discharges due to the channel improvements.
Flood hydrograph routings were performed for this study using the computer program
HEC-1 Flood Hydrograph Package developed by the US Army Corps of Engineers
Hydrologic Engineering Center. The routing methodology is described in EM 1110-2-
1417, dated 31 August 1994 and other hydrologic publications.
ROUTING MODEL
Routing Method. The modified Puls method of routing was used in this study to route
flood waves downstream. The modified Puls routing technique takes into account the
storage in the overbanks of the stream in routing the flood wave downstream. Overbook
storage is determined using the computer program HEC-2, Water Surface Profiles. The
application of this routing method to streams is described in the above referenced EM and
C-4
also in The Hydrologic Engineering Center Training Document No. 30, River Routing
Techniques with HEC-1 and HEC-2, dated September 1990. The first step in developing
the model was to determine the routing points which would be used. Unit hydrographs
were then developed for the intervening drainage area between these points and rainfall
runoff was applied to the unit hydrographs to determine flood hydrographs for the
intervening areas. These flood hydrographs were then routed downstream to the next
routing point and combined with the flood hydrograph for the intervening area and routed
to the next point.
Unit Hvdrographs. Unit hydrographs were developed using methods developed by the
Soil Conservation Service(SCS) and described in the SC. National Engineering
Handbook, Section 4, Hydrology. This method utilizes the inter-relationship between
meteorological and basin watershed characteristics to develop parameters for determining
unit hydrographs.
Watershed Characteristics. The Hominy Swamp Basin is typical of basins within the
Coastal Plain Region of North Carolina. Slopes are generally flat and flood plains are
wide. The basin is intensely urbanized with commercial and residential development
being present.
Soil Characteristics. One of the watershed characteristics utilized in developing the unit
hVArnora„hQ by Q(`Q mPtIb6^%A n , 1Q the cn;l }sme in the ?i,atPrchPr? T%,- enil in the
Hominy Swamp Basin was determined to be most closely classified as _ Group C soil
using the SCS classification.
Runoff Curve Numbers. One of the parameters necessary for developing the lag time
associated with unit hydrographs is the runoff curve number, which is related to the type
of development in the basin. These curve numbers were developed based on tables in
SCS publications using antecedent moisture condition I I I denoting wetter than average
antecedent soil conditions. Condition I I I was used to reflect the more severe conditions
associated with flooding. The curve numbers used were based on urban conditions with
commercial development and small residential lots which are typical of the area. Table
C-5 gives curve numbers used in the study.
Lag time. Lag time from the center of the unit rainfall to the peak of the unit
hydrograph is dependent on the slope of the watershed, the basin length and the curve
number. Table C-5 gives the lag times at the locations of the unit hydrographs.
C-5
Table C-5
Unit Hydrograph Parameters
Drainage Runoff Lag
Area Curve Time
Location (sq mi) Number (hours)
' Above Ward Ave. 4.8 80 4.8
New Elizabeth Road 1.7 80 4.0
CSXRR 1.5 80 6.5
Black Creek Road 1.8 75 5.7
Mouth of Hominy 5.9 70 12.0
Swamp '
Once the lag times were determined, the computer math model HEC-1 was used to
develop the unit hydrographs at the desired locations. The lag time was input to the
model and the unit hydrographs were determined by the model.
DESIGN STORMS
Hypothetical Storms. Frequency storms were determined using U.S. Weather Service
report TP-40. Point rainfall for various frequency storm events were determined from
TP40 and used as input to HEC-1 to develop incremental rainfall values for various
frequency storm events. Table C-6 gives the rainfall values form TP-40 which were used
in the study.
Table C-6
24-Hour Point Rainfall (TP-40)
Frequency Event
2 year
5 year
10 year
50 year
100 year
500 year
Point Rainfall (inches)
3.80
5.00
5.90
7.90
8.50
12.50
Standard Project Storm. The standard project storm for the basin represents the most
severe flood producing depth-area-duration rainfall relationship and isohyetal pattern of
any storm that is considered to be reasonably characteristic of the region in which the
drainage basin is located. The standard project flood index rainfall was obtained form
EM 1110-201411, Standard Project Flood Determinations". The Hydrologic Engineering
Center computer program HEC-1 was used to determine the rainfall distribution. Table
C-7 shows pertinent storm data.
C-6
Table C-7
Standard Project Storm Data
Index rainfall 12.7 inches
Storm Duration 96 hours
Total Rainfall 18.21 inches
Maximum 24 Hour Rainfall 13.77 inches
DESIGN FLOOD HYDROGRAPHS
Hypothetical Floods. Flood hydrographs for hypothetical or frequency flood events
were determined by applying runoff from the storm events described above the
appropriate unit hydrographs. There were no historical flood hydrographs available
within the basin from which to develop loss rates. It was therefore necessary to adjust
loss ratP? „nt;t theT eakc of the v rion flood -hydro-graphs approximated the discharge
frequency curve. Infiltration rates vane om . inc per our )r Me 10 Vw Y -,"I
frequency flood to .22 inch per hour for the 5 year frequency event. Based on loss rates
from other studies these values appear to be reasonable. Plates C-2 through C-5 show the
comparison of the frequency curves based on the routed flood hydrographs and the curves
developed using the USGS regression equations. As indicated earlier, the railroad fill has
an effect on discharges downstream of the fill. This effect is shown on Plates C-4 and C-
S %%,'k,- the rrnrtPCt inn g ar 1??=per than the re?re ion eauation curves
Standard Project Flood. The standard project flood(SPF) was determined by applying the
Standard Project storm(SPS) runoff to the unit hydrographs for various drainage areas.
SPF runoff was determined by applying initial losses and infiltration losses to the SPS
rainfall.
WATER SURFACE PROFILES
General. Water surface profiles were developed using the Hydrologic Engineering
Center program HEC-2, "Water Surface Profiles". Water surface profiles for various
frequency flood events were developed for existing conditions and for various flood
control alternatives in order to determine the economic feasibility of modifications for
Hominy Swamp.
Physical Data. Channel and valley geometry were defined by field surveys, USGS
topographic maps, and photos of the project area. The channel of Hominy Swamp is
generally well defined except for the lower portion near the mouth. The lower portion of
the channel is typical of coastal swamps with a wide flat channel and low banks. As the
channel progresses upstream it becomes more defined with higher banks. Overbanks are
very wide near the downstream end and becomes progressively narrower in the upstream
reaches. Overbank conditions vary from heavily wooded near the downstream end of the
swamp to lightly wooded and grassy further upstream as it flows through the more
populated area of Wilson. The floodplain in the lower reaches of the stream below Black
C-7
Creek Road are largely undeveloped. The floodplain above black Creek Road becomes
progressively more developed going upstream. Upstream of US Highway 301 the
floodplain is highly developed with dense commercial and residential development in the
floodplain. The channel Mannings "n" values used for existing conditions varied. A
channel "n" value of 0.125 was used in the lower portion which as stated above is less
defined due to the low swampy characteristics. As the channel becomes more defined
and characteristic of an urban stream, the channel "n" value of .045 was used. The
overbank "n" value used was 0.15. These values were chosen based on similar streams.
Discharge Versus Drainage Area. In order to determine discharges along the stream,
discharge vs. drainage area relationships were determined for the standard project flood
and various frequency flood events. Using discharges at known points curves were
drawn for the full range of discharges and drainage area required for this study. Plate C-5
shows these curves for various flood events.
Water Surface Profiles for Existing Conditions. Water surface profiles for existing
conditions for the. SPF and various frequency floods were generated for use in
determining the economic damages due to flooding along the study reach. Plate C-6
shows the existing condition profiles for the 100 year flood and the 10 year flood and
similar floods for the modified channel conditions, discussed later.
CHANNEL IMPROVEMENT EVALUATIONS
Structural Alternatives. The alternatives investigated to reduce flood damages on
Hominy Swamp consisted of channel modifications along various reaches and addition of
a culvert under the CSXRR fill upstream of US Highway 301. Improvements evaluated
began at Black Creek Road and extended to Goldsboro Street. In all
Recommended Channel Design. The recommended channel improvement scheme
involved clearing the stream from Black Creek Road to the railroad spur downstream of
Goldsboro Street. The length of the project is approximately 2.2 miles long. The
recommended plan also involves placing an additional 12 feet diameter culvert under the
CSXRR fill upstream of US Highway 301. The purpose of the clearing downstream of
the railroad spur and the channel improvement from the spur to the CSXRR was to
mitigate for the increased discharges created by the additional culvert during flood flows.
Water Surface Profiles for Improved Conditions. The HEC-2 model was modified to
reflect hydraulic conditions that will exist with the recommended changes in place. The
most significant changes in the backwater model were made to the cross sectional
geometry and Manning's "n" values. A channel "n" value of 0.07 was used for the
clearing reach and a channel "n" value of 0.35 was used for the improved channel.
Overbank "n" values remained unchanged from those used for the existing conditions.
Revised Peak Discharges. An analysis was performed to determine the impacts of
reduced floodplain storage on flood waves passing through the channeliztion project.
C-8
The storage routing model which had been developed for the exiting conditions was
modified to reflect the decrease in floodplain storage. Also the elevation discharge
relationship for the culvert was changed to reflect the additional culvert under the railroad
fill. The design floods were routed through the reach with the new criteria.
PROJECT IMPACTS
Stage Reductions. Table C-8 shows water surface elevations and stage reductions at
representative locations for existing conditions and for improved conditions with the
recommended channel project for various frequency flood events and the SPF. Refer to
plate C-6 for the location of the cross section station numbers shown in column 1 of
Table C-8.
Table C-8
Existing and Improved Water Surface Elevations
10 Y ear Frequency Flood 25 Y ear Frequency Flood
Station Existing Improved Reduction Existing Improved Reduction
Number (ft., msl) (ft., msl) (ft., msl) (ft., msl) (ft., msl) (ft., msl)
8050 82.0 82.1 -.1 82.3 82.4 -0.1
14530 87.0 87.1 -.1 87.6 87.8 -0.2
18006
')QAQ0 91.9
91 R 91.6
91 R .3
0 92.5
94.7 92.3
9 0.1
4 0-0
21700 94.7 94.3 1.3 95.2 94.8 0.4
23886 98.8 95.6 3.6 99.3 96.7 2.6
24790 99.3 .96.6 2.7 99.8 98.2 1.6
24990 100.8 100.0 0.8 102.5 1.01.2 1.3
28230 102.6 101.2 1.4 104.3 102.2 2.1
31920 105.8 105.2 0.6 107.5 106.7 0.8
33880 107.5 107.4 0.1 108.6 108.6 0.0
100 Year Frequency Flood
Station Existing Improved Reduction
Number (ft., msl) (ft., msl) (ft., msl)
8050 82.8 83.0 -0.2
14530 88.3 88.6 -0.3
18006 93.4 93.4 0.0
20400 94.8 94.8 0.0
21700 95.9 95.6 0.3
23886 100.1 98.7 1.4
24790 100.6 99.2 1.4
24990 105.1 103.1 2.0
28230 107.2 105.8 1.4
31920 109.2 108.9 0.3
33880 110.0 109.9 0.1
Standard Project Flood
Existing Improved Reduction
(ft., msl) (ft., msl) (ft., msl)
83.8 84.0 -0.2
89.5 89.7 -0.2
94.2 94.4 -0.2
95.7 95.8 -.01
96.9 96.6 0.3
101.2 100.3 0.9
101.7 100.7 1.0
109.7 107.1 2.6
112.4 107.8 4.6
113.1 110.5 1.6
113.6 111.7 1.9
C-9
Downstream Impacts. The placement of the additional culvert under the railroad fill will
produce increased discharges downstream. In order to mitigate for this and not increase
stages downstream it was necessary to improve channel conditions downstream until the
increase in stages were insignificant. In order to do this it was necessary to clear the
channel form Black Creek Road (station 180+00) to the railroad spur below Ralston
Street (station 227+50) and widen the channel from the railroad spur to the CSXRR fill
(station 247+90). Downstream of station 180+00 as seen in table C-8 above, the
increases are considered insignificant.
CHANNEL PROTECTION MEASURES
Channel Protection Criteria. Channel protection design was carried out in accordance
with EM 1110-2-1601. Any improved channel reach for the stream where average
channel velocity exceeds 6.0 feet per second will require stabilization using either rip rap
or other approved materials.
Open channel Velocities. Table C-9, below, shows the open channel velocities with and
without the project at representative locations along the channel improvement excluding
bridge locations. Based on the channel protection criteria above, velocities for the
improved channel reaches are not erosive and the channel will therefore not require
stabilization in the open reaches between bridges except for areas opposite drainage pipe
outlets.
Table C-9
Channel Velocities - Exiting and proved
100 Year Frequency
Station Existing Improved
Number (ft/sec) (ft/sec)
18006 0.8 1.4
20400 0.9 1.5
21700 1.0 2.7
23886 _ 1.9 4.2
24790 2.4 2.4
28230 2.4 3.1
Standard Project Flood
Existing Improved
(ft/sec) (ft/sec)
0.9 1.6
1.0 1.8
1.1 3.3
1.9 4.2
2.9 2.9-
1.9 3.3
Bridge Velocities. Table C-10 shows bridge velocities, with and without the project, at
all the bridges within the project reach. Based on velocity criteria, riprap or other erosion
protection methods will be required at the CSXRR fill and Goldsboro Street.
C-10
Table C-10
Bridge Velocities Existing and Improved
100 Year Frequency Standard Project Flood
Existing Improved Existing Improved
Bridge Site (ft/sec) (ft/sec) (ft/sec) (ft/sec)
Black Creek Road DS 4.1 5.0 2.2 3.4
US 4.3 4.9 1.8 2.9
RR Spur DS 2.8 5.8 ?A 6.4
US 2.7 5.9 3.3 4.9
Ralston Street DS 3.0 5.5 3.1 6.5
US 3.0 4.8 3.1 6.4
lg way 301 us M 1.4 .
US 1.3 5.0 1.4 5.0
CSXRR DS 4.7 8.5 5.2 10.1
US 9.8 4.6 11.5 6.3
Phillips Street DS 2.1 _ 2.9 1.6 3.0
US
Lodge Street DS
US
Goldsboro Street DS
US
2.4 3.5 1.9 3.8
2.4 3.5 1.9 3.8
4.7 6.3 4.4 6.7
4.1 6.0 2.7 5.2
Riprap Design. Evaluations for riprap requirements were based on criteria in EM 1110-
2-1601, Hydraulic Design of Flood Control Channels" dated 1 June 1991. Riprap size
requirements were determined using the US Army Corps of Engineers Waterways
Experiment Station (WES) computer program "Riprap I I". Riprap was sized for the 100
year design flood. There is a 63.4 percent chance that the 100 year design flood will be
exceeded during the 100 year project life therefore riprap maintenance should be part of
the overall project design. Table C-11 shows the results of the riprap analysis. A more
detailed analysis of the riprap requirements will be performed during the design stage of
the project based on the final channel configuration and layout.

C-11
Table C-11
Bridge Ri_prap Parameters
Bridge Location
Average Velocity
Computed Local Depth Average Velocity
Specific Weight of Stone
Stone Layer Thickness
Minimum D30
Minimum D90
Bridge Location
Average Velocity
Computed Local Depth Average Velocity
Specific Weight of Stone
Stone Layer Thickness
Minimum D30
Minimum D90
CSXRR
8.5 ft/sec
11.08 ft/sec
165 lbs/cu. ft
15 inches
.61 ft
.88 ft
Goldsboro Street
6.3 ft/sec
6.82 ft/sec
1651bs/cu. ft
9 inches
.37 ft
:53 ft
C-12
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REPLY TO
ATTENTION OF:
CESAS-RE-R (405)

DEPARTMENT OF THE ARMY
SAVANNA/ DISTRICT. CORPS OF ENGINEERS
P.O. BOX 8"
SAVANNAH. GEORGIA 3140240889
12 September 1995
MEMORANDUM FOR Commander, Wilmington District, Attn.: CESAW-PM-
C/Carol Neissen
SUBJECT: Feasibility Level Study, Hominy Swamp Channel
Improvement Project, Wilson, NC.
1. Enclosed, per your request, is one original of the completed
Real Estate Section for the subject.
2. Additionally enclosed is a disk containing the text in both
the WordPerfect 5.1 and the Word 6.0 formats.
3. Should you have any questions concerning the aforementioned,-
the Technical.Manager?and POC for this action is William W.
(Bill) Horn [phone].
ceWs ?
Encl C arles Wash
Acting Chief, Real Estate Division

REAL ESTATE SECTION
FOR
Y
FEASIBILITY LEVEL STUDY
HOMINY SWAMP CHANNEL IMPROVEMENT PROJECT
WILSON, WILSON COUNTY, NC

Prepared by: William W. Horn, CESAS-RE-AP, [phone]
Project- Manager: Carol Neissen, CESAW-PM-C, [phone]
Date. 11 September 1995
1
P"?
1. STATEMENT OF PURPOSE: This real estate document is
i preliminary and tentative in nature and is provided for planning
purposes only. The real property requirements and the estimate
of value are subject to change even after approval of the.
detailed Project Report.
The Project Sponsor (PS) for this project is the City of Wilson,
NC. The writer visited the City of Wilson and visually confirmed
a major portion of the information presented in this report.
2. AUTHORIZATION: This study is authorized under Section 205 of
the Flood Control Act of 1948, as amended.
3. GENERAL DESCRIPTION OF PROJECT: The proposed project area
lies entirely within the city limits of Wilson, NC. The
project's main objective is widening and clearing the channel
limits of Hominy Swamp. The project includes a channel widening
section and a clearing and snagging section for flood control in
the southern portion of the community. Silting up, stream bank
erosion, and vegetation growth have dramatically reduced the .
stream volume and capacity causing regular and recurring flooding
of a city housing subdivision, a city park, and other low lying
lands in the southern portion of the.city. This project will
alleviate these flood conditions except on those occasions of
unusual water volume, i.e. the 100 year flood.

The Real Estate requirements for the project consist of the
following areas: 18 tracts containing 10.90 acres of land area
needed for clearing and snagging, 32 tracts containing 15.99
acres of land area needed for channel improvements, and one tract
containing 12.00 acres of.land area needed for disposal of debris
cleared and soil dredged from the channel of Hominy Swamp. These
areas are based on a project perimeter established at 55 feet on
either side of the center line, or 110 feet total width, in the
channel improvement section, and 50 feet on either side of the
center line, or 100 feet total width, for the snagging and
clearing section of the project. The existing channel varies in
width from approximately five feet to fifteen feet. It is
planned the work area will be contained inside the aforementioned
perimeter, but will swing from side to side within the project
2
P-1-
based on the side banks and soils composition and consistency,
the topography, the channel flow,-and any other conditions as
determined.
The total length of the project is 2.10f miles. and it run's in a
generally southeasterly direction. The project begins at
Goldsboro Street and ends at Black Creek Road. It crosses four
other major streets in Wilson, Lodge Street, Phillip Street, U.S.
Highway 301/Ward Boulevard, and Ralston Street, as well as the ~
main line-and one spur of the Norfolk and Southern (CSX) Railroad
(See Exhibit "A" for a map of the project area). The project
crosses,, or is a boundary for, a number of different property
classifications, including recreational (Phillips Park),
residential, commercial, industrial, and woodland.
In addition to the dredging and clearing required for the channel
widening and cleaning, a 12 foot diameter culvert will be bored
and jacked through the fill under the CSX railroad main line to
make the improved conditions continuous. The Project Manager
stated that CSX Railroad Company has given verbal indications a
licensing agreement can be negotiated for this work.
No structures will be impacted by project. construction.
There are no known items of historical significance within the
project boundaries.
4. PROJECT SPONSOR RESPONSIBILITIES: Title to the lands
acquired for this project will not be vested in. the name of the
United States. Prior to. advertisement of any construction
contract, the PS shall furnish to the Government evidence they
have acquired all necessary rights-of-way (LERRD's) and permits
for construction of the project and transit to and from the
disposal area. The PS shall also furnish the Government a right-
of-entry to these lands for project purposes and evidence
supporting their legal authority to grant such rights to the
land. The PS shall accomplish all relocations of buildings,
highways, railroads, bridges (other than railroad bridges)., storm
drains, utilities, cemeteries and other facilities, structures
and improvements determined by the Government to be necessary for
construction of the project.

3
,3
s
5. GOVERNM=-OWNED LAND: There are no federal government-owned
lands lying within the proposed project area.
6. HAZAMOUR OR TOXIC WASTE: The Environmental Section of the
Wilmington District reported in an Environmental Analysis,
Additional Information, as of 16 February 1990, "One old landfill
and/or toxic waste site buried alongside of Hominy Swamp below
Ralston Street has been located..." in the project area. The
exact location is on the east bank of Hominy Swamp between
Ralston Street and the Norfolk and Southern Railway Company,
Inc., spur line. The Environmental Section recommends the work
area be confined to the west bank of Hominy Swamp in that
vicinity to avoid any disturbance of the landfill.
7. APPRAISAL INFORMATION_:_ The appraisal report valued 38.89
acres of land, primarily along the meandering Hominy Swamp. The
property rights appraised are three different easements, each
having a duration of fifty (50) years. The evaluation of highest
and best use determined four different land uses in the project;
commercial, residential, farm and waste land (swamp).
There are approximately 51 separate ownership's in the project
area. The gross appraisal report for the project shows a value
estimate of $408,250.
Channel improvement easements will be required for 32 tracts
containing 15.99 acres, of which 10.80 acres are zoned commercial
and 5.19 acres are zoned residential. The estimated value of the
commercial tracts is $149,971. It should be noted, the 5.19
acres zoned residential in this project for which the perpetual
channel improvement easement is to be acquired have a zero value.
This is due to the theory of offsetting benefits which applies in
North Carolina. Offsetting benefits are created when the value of
the land along a project is predicted to increase after the
project; in this case the prospects for continuing flooding are
reduced.
4
D'11
Clearing and snagging easements will be required for 18 tracts
containing 10.90 acres zoned rural. The estimated value of these
tracts is $3,563.
A dredged material disposal easement will be required for the 12
acre disposal site in which the dredged material and debris
generated from project operations will be placed. It should be
noted the disposal site selected is in an area of affluent
housing and thus the value assigned is exceptionally high for
such land use. The estimated value of the dredged material
easement is $254,853. This particular site was provided by the
City Engineer and it is recommended in future studies of this
project that alternative, less costly, and more appropriate
disposal sites be considered.
There are no improvements in the project area, nor are there any
improvements close-enough to the project to be adversely
effected. No negative impact on property values are predicted to
result from the project. The zoning is fairly consistent with
the land use at this time, and the project should not affect the
zoning. The current land uses in the project area should not
8. UNIFORM RELOCATION ASSISTANCE COST (P.L. 91-646. AS AMENDED):
The project will not require the displacement of any residents or
businesses and there will be no Relocation Assistance required.
9. ACCESS TO THE PROJECT AREA: Access to the project ranges
from good to excellent and will be gained from either side of the
channel as appropriate. Public access to the project is
available throughout its length.
The northwesterly terminus of the project is the Goldsboro Street
bridge. The property on the southeast corner at the swamp and
the bridge is a residential lot and structure and at the
southwest corner is a commercial lot and building. Access to
this northern project terminus can be gained from public lands.
5
Q.s
The project next passes under Lodge Street and parallels the
west side of Norris Boulevard. Access to the project is possible
the entire length of Norris Boulevard from the street.
The project then passes under Phillip Street (the extension
of Norris Boulevard) and meanders through Phillips Park, a city
owned recreation area. If required, this park would make an
excellent staging area.
Moving on downstream the project passes under the main line
of the CSX Railroad.
The project next crosses under U.S. Highway 301, a/k/a Ward
Road, with access available from the northeasterly corner at the
intersection of the highway and the project.
A short distance further downstream the project crosses
under Ralston Road, a city maintained two lane street.
The next point of access, moving southeasterly, is near a
spur of the CSX Railroad which crosses the project.
The southeastern terminus of the project is at Black Creek
Road, SR 1606, a two lane, state maintained, blacktop highway.
The disposal area is 12 acres of a 35 acre tract located
approximately three miles north of the northern terminus of the
project. Access to the disposal area will be by public roads.
10. RELOCATION OF HIGHWAYS, ROADS RAILROADS PIPELINES AND
UTILITIES: Not applicable (none necessary).
11. STRUCTURE Alti'D IITILITIES (P LTC LAW 85-500) : There are no
known utilities or structures within the project limits that will
require relocation.
12. MINERAL ACTIVITY: There are no known mineral deposits or
active mining operations within the proposed project area.
6
9- (1
l
13. TIMBER AND VEGETATION COVER: The clearing and snagging will
consist of the removal of debris and the cutting of saplings and
underbrush. Large trees are not to be cut unless they are leaning
and in danger of falling into the channel. The project does not
contain sufficient land area to consider marketing the timber.
14. PRIME AND UNIQUE FARM LAND: The proposed project area is
not in a rural area, and there are no unique farms along the
project path.
15. ATTITUDE OF PROPERTY OWNERS: No property owners were
In AlnTl e
16. RELOCATION OF TOWNS AND CEMETERIES: There are no known
cemeteries within the project area, and no towns will need to be
moved.
17. PROPOSED ESTATES: For those project areas.in private
domain a Channel Improvement Easement, a Clearing and Snagging
Easement, or a Dredged Material Placement Easement will be
needed.
CHANNEL IMPROVEMENT EASEMENT: A perpetual and assignable right
and easement to construct, operate, and maintain channel
improvement works, over and across (the land ' described in
Schedule A) (Tracts Nos. and ) for.the purposes as
authorized by the Act of Congress approved .
including the right to clear, cut, fell, remove and dispose of
any and all timber, trees, underbrush, buildings, improvements
and/or other obstructions therefrom; to excavate, dredge, cut
away, and remove any or all of said land and to place thereon
dredge or spoil material; and for such other purposes as may be
required in connection with said work of improvement; reserving,
however, to the owners, their heirs and assigns, all such rights
and privileges as may be used without interfering with or
abridging the rights and easement hereby acquired; subject,
7
O -7
however, to existing easements for public roads and highways,
public utilities, railroads and pipelines.
CLEARING AND SNAGGING EASEMENT: A 50 year assignable right and
easement to enter lands for removal of obstructions to -flow, and
to operate and maintain stream clearing and snagging works in the
future as may be necessary in, on, over, and across the land
hereinafter described, for the Hominy Creek Swamp Channel
Improvement Project, for the purposes authorized by the Act of
Congress, approved , consisting of the right to
remove from the stream all trees (dead trees, down trees, trees
in imminent danger of falling, and trees growing over or into the
channel that impede the natural water flow), snags, stumps, logs,
and other debris that are anchored, floating, or submerged above
the natural bottom of the stream to an unobstructed condition; to
remove potential obstructions lying within the creek and within
feet landward of the waters or banks edge, consisting of
logs, down treetops, limbs, uprooted trees, undercut stumps, and.
other debris; and to place removed material -within an additional
foot wide strip on each landward side of-the stream beyond
the above referenced feet strip so that the deposited
material shall not obstruct natural drainage's, drainage ditches,
croplands, and other beneficial uses; further, living, firmly
f rooted trees and cypress knees growing on bank slopes and
elsewhere within the right-of-way, which do not impede the water
flow in the creek, will not be removed; and for such other
purposes as may be required in connection with said work of
clearing and snagging improvements; reserving, however to the
owners, their heirs and assigns, all such rights and privileges
as may be used without interfering with or abridging the rights
and easement hereby acquired, subject, however, to existing
easement for public roads and highways, public utilities,
railroads, and pipelines; the land covered by this easement being
that portion of those lands described in the attached "Schedule
.
All
. DREDGED MATERIAL DISPOSAL EASEMENT: A 50 year assignable right
and easement to survey, construct, operate and maintain a dredged
material containment area on the land herein described, including
the right to construct and maintain dikes, slope protection,
drainage features and structures and to accomplish any
alterations of,contours of said land for the purpose of
8
p_$
accommodating the placement of dredged material including the
burning and burial of debris as necessary in connection with such
works; to place, to borrow, excavate and remove said dredged and
other material; to clear, cut, fell and remove any and all trees,
timber, underbrush, or other obstructions therefrom, and for such
other purposes as may be required in connection with said works
including environmental monitoring and corrections; to undertake
any management practice designed to enhance use or extend life of
said land for the deposit of dredged material; subject to
existing easements for public roads and highways, public
utilities, railroads and pipelines; reserving, however, to the
grantor (project sponsor), its successors and assigns, all such
rights and privileges as may be used and enjoyed without
interfering with the use of the Project for the purposes
all ad .-PA Y
herein conveyed. PROVIDED, HOWEVER, that no permanent or
temporary structures for human habitation shall be constructed or
maintained, and no other structures shall be constructed or
maintained on the land except as may be approved in writing by
the representative of the Grantee in charge of the Project
(project sponsor).
18. ESTIMATED VALUE OF REAL ESTATE: The estimated value for
each of the project real estate segments and the administrative
costs-are presented below:
Chart of
Accounts
No. Item Cost Estimate
O1R1B Lands
Dredged Material Placement Easement
12.00 acres zoned residential
Channel Improvement Easement
5.19 acres zoned residential
10.80 acres zoned commercial
Clearing and Snagging Easement
10.90 acres zoned rural
Total (38.89 acres)
$254,853
0
149,791
3.563
$408,207
9
D 'q
Chart of
Accounts
No. Item
O1R1B Improvements
O1R1B Mineral Rights
O1R1B Damages
01RX Contingency
01F20 P.L. 91-646 Costs
01B Acquisition Costs for 51 ownership's
01B10 Federal
OIB20 Non-federal
01BX Contingency
Total Estimated Real Estate Costs
Rounded to
hominy3.doc

Cost Estimate
0
0
0
102,052
0
38,250
102,000
35.063
$685,572
$685,500

10
DISPOSAL 2 ;
SITE 3
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LODGE ST.
292+40
CHANNEL IMPROVEMENT
y
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US 301
6SPUR
1000 0 1000 2000 3000 4000 5000 6000 7000 FEET
CULVERT ADDITION
STATION 248+90
STATION 227+50
TO
STATION 292+40
51 ?61110
227+50
179+30
O
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CLEARING AND SNAGGING
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WASTEWATER
TREATMENT PLANT
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O O
HOMINY SWAMP
CITY OF WILSON, NORTH CAROLINA
REAL ESTATE
REQUIREMENTS
U.S. ARMY ENGINEER DISTRICT WILMINGTON, N.C.
D-11 Exhibit A
r
6
ECONOMIC APPENDIX
HOMINY SWAMP. WILSON. N.C. SECTION 205 STUDY
SOCIOECONOMIC CONDITIONS
Community Description. The city of Wilson is located on the
eastern coastal plain of North Carolina in the center of Wilson
County. The city lies just northeast of Contentnea Creek, 45
miles east of Raleigh and 18 miles south of Rocky Mount. Hominy
Swamp rises northwest of Wilson and flows southeasterly through
the city to Contentnea Creek. Land in the area is smooth and
nearly level, but short breaks separate the uplands from the
flood plains of the larger streams. Land elevations vary from
less than 80 feet above sea level along the streams to 160 feet
northwest of the city. Wilson has a mild climate with an average
annual precipitation,of 47 inches and an average temperature of
61 degrees Fahrenheit.
Historic Population and Income. Wilson had a 1990
population of 36,930 and an estimated July, 1993 population of
37,638. Wilson County had a 1990 population of 66,061 and an
estimated July, 1994 population of 67,688. The area's population
is growing very slowly. The 1990 census showed Wilson having
9,812 family households and 14,461 housing units. About 49 per
cent were owner occupied with a median value of.$64,500.
Household size averaged 2.45 persons. The city covers a land
area of 18.5 square miles.
The per capita income for Wilson County in 1979 was $9,362,
and had increased 19 percent by 1989 to $11,134 adjusted for
inflation. The per capita income in 1979 was 100 percent of that
of the State and in 1989 was 97 percent. In June, 1992, Wilson
County had a labor force of 37,430 and employment of 32,900 with
an unemployment rate of 12 percent. About one-fifth of the
population was below the poverty level and one-seventh were over
65. Forty-seven percent of the population in the city is black.
The largest employers are manufacturing, government, farming,
services, trade, and construction. The principal industries are
tire and rubber, metalworking, textiles, tobacco,
pharmaceuticals, and equipment. Wilson is a regional banking,
trade, and services center for surrounding rural areas. The
town's economy is also helped by traffic on highways I-95, 301,
264, 58, and 42.
Projected Socioeconomic Conditions. The most recent OBERS
projections by the Bureau of Economic Analysis show that Wilson
County would have a population of 68,200 in 1995; 70,000 in 2000;
and 76,500 in 2040. OBERS projections are very close to recent
growth rates and are very attainable for the county. Projected
population, total personal income, and per capita income for
Wilson County are presented in table E-1 below.
E-1
Table E-1 - Projected Population and Income
1995 2000 2005 2010 2040
Population
68,200 70,000
Total Personal Income* 825.8
Per Capita Income* 12,104
891.6
12,745
71,500 73,000 76,500
947.2 999.0• 1,272.7
13,251 13,680 16,636
* Per capita income in 1982 dollars, total personal income in million 1982
dollars
PRINCIPAL FLOOD PROBLEMS
Historic Flooding Problems. Flooding along Hominy Swamp has
Been A ma J n-r _3 n em Tilt! Carus of
prepared a DPR in 1968 that first addressed the flood problems.
A Flood Insurance Study was prepared in 1982 for the city which
included Hominy Swamp. A Reconnaissance Report on the Neuse
River Basin was published in 1984 and included Hominy Swamp as a
local flood problem.
Flood damages on Hominy Swamp begin at about the 4-year
October 1964. The October 1964 flood approximated the 20-year
flood on Hominy Swamp. Damages from that flood at the time were
estimated at $55,000. Most of the flooding occurs between Black
Creek Road and Raleigh Road. The principal flood damages are to
residential and commercial development along the stream. The
flood plain area is shown in Figure 1. Principal damage centers
include the area along Black Creek Road and the area upstream of
the CSX Railroad: Damages are lessened by most homes having
foundations from 1 to 4 feet above the ground.
Average Annual Flood Damage Catectories. Average annual
flood damages were computed using expected flood profiles from
the hydraulic analyses having recurrence intervals from 1 to 2000
years. Building types and values were determined during field
economic surveys. Buildings were valued by using depreciated
replacement values which are approximated by market value in most
cases. Current tax valuations were used to assist in determining
relative building values. Floor elevations for almost all
buildings were field surveyed, with any remaining elevations
taken from known building elevations nearby or topographic
mapping done for the flood insurance study. There are 297 homes
and 45 commercial buildings in the 100-year flood plain.
Depth-damage curves for residential structures are contained
in the Wilmington District computer program 76107B and include
damages to garages and outbuildings. Residential curves have
been modified to agree with FEMA damage claims experience through
C-2
1989, in areas where sufficient data are available. Contents
ratios of 50 per cent were used to account for somewhat low
structure values, items that are not included in the structure,
and income growth expected by the base year. This is also
consistent with content values used in standard homeowners
insurance policies in North Carolina and studies done by the
Institute for Water Resources. Automobile damages were
calculated by finding the motor vehicles registered per household
of 1.9 and expecting 1 car to be left for every two homes. The
car was expected to sit at the ground elevation for the house,
and was valued at $3000. Automobile depth-damage curves were
obtained from the New York District's Passaic Basin study.
Residential flood damages, including automobile damages, amounted
to 28 percent of the average annual damages.
Flood damages were calculated for 13 frequencies ranging
from the 1-year to Standard Project Flood (2000-year). Depth-
damage curves for residential and commercial buildings were
originally obtained from the Galveston District. The curves for
commercial buildings are now contained in the Wilmington District
commercial flood damage program 76109D for 50 establishment
types. Content damages were calculated separately by type as a
percentage of the structure. Commercial curves have been
compared to actual flood damage records at several locations, and
have been modified slightly. Commercial flood damages made up
10 percent of the average annual damages,.
Industrial flood damages were determined after contacting
each industry in the flood plain and determining the value of
structures, equipment, and inventories. Damages were estimated
for each flood depth based on information obtained from the
industry and previous flooding in other locations. Industrial
damages made up 51 percent of the average annual damages.
Emergency costs were estimated for all floods by summing the
residential and commercial damages and estimating emergency costs
to be 14.4 percent of the damages. This relationship came from
the Adkin Branch study, which looked at emergency costs in more
detail. Previous emergency cost were taken from comprehensive
data gathered by the Wilmington District after hurricane Agnes in
1972 and updated for price level. Emergency Costs amounted to 6
per cent of the annual damages.
• Damages to transportation facilities like streets,
railroads, and bridges were computed from the Wilmington District
Transportation program 76112A. Depth-damage curves were
formulated from information from the Galveston and Baltimore
Districts and the Federal Highway Administration. Transportation
damages made up 2 percent of the average annual damages. Utility
damages were computed as 3.8 percent of the residential,
commercial, and industrial damages from relationships developed
in other floods. The expected utility damages amount to 3
percent of the total flood damages.
E-3

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Table E-2 shows expected flood damages for each frequency
event by category under existing conditions for all development
in the flood plain. Table E-3 shows the average annual damages
and percentage by category for the existing flood damages.
Table E-3 - Existing Average Annual Flood Damages
Category of Damageable Property Average Annual Percent
Flood Damages Value Thous $ Damages Thous $ of Total
Residential 25,259.5 390.5 28
Commercial 12,698.7 136.6 10
Industrial 73,980.0 710.0 51
Utilities 5,202.5 47.0 3
Transportation 4,380.7 32.4 2
Emergency Costs 75.9 6
Totals 121,521.4 1,392.4 100
Residential includes automobiles
Flood Damages by Reach. Average annual flood damages were
computed for natural conditions and modified by the proposed
project (HS2512b) for,each reach along Hominy Swamp. Expected
damages by category for each reach and percentage of damages
within the reach are shown in table E-4. Eighty percent of the
damages lie between Black Creek Road and Tarboro Street, and
another thirteen percent between Tarboro Street and Park Avenue.
Expected flood damages above Park Avenue are only eighty-nine
thousand dollars on an average annual basis.
FLOOD PROTECTION MEASURES
Stream Channel Improvements. Of the various measures
available to reduce flood damages along Hominy Swamp, stream
channel improvements were expected to be the most feasible.
Eight plans of stream channel improvements were considered to
determine the optimum plan to maximized net NED benefits. Seven
reaches were studied from Below Black Creek Road to Forest Hills
Road. Channel improvement plans were analyzed on the six reaches
below the confluence with Little Hominy Swamp. Bottom widths
were examined ranging from 25 to 40 feet. The beneficial effects.
of each plan were compared to expected costs, and various widths
for each reach were analyzed. Project formulation was done using
October 1995 benefits and costs and is shown in table E-5.
BENEFIT-COST ANALYSIS
Benefit Evaluation. Benefits from the proposed channel
improvement plan are the difference between flood damages with
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-6
and without the project. Damages for each type of flood prone
development were computed for each reach using modified stream
profiles from the hydraulic analyses. Benefits are computed for
existing conditions. Projects were evaluated having a service
life of 50 years at an interest rate of 7 5/8 percent. Because
the area is fully developed and flood plain inventories-over the
years have shown constant conditions, no increase in future flood
damages is expected.
First Costs and Annual Costs. First costs and expected
operation, maintenance, and replacement costs were determined
during the Detailed Project Report after completing physical
surveys, field investigations, and subsurface examinations.
Interest and amortization were determined over a period of
analysis of 50 years at an interest rate of 7 5/8 per cent.
Interest during construction was computed on first costs for a
construction period of 12 months. Operation and maintenance
costs for each plan were estimated and included in the average
annual costs. First costs and average annual costs are shown in
table E-5.
Comparison of Benefits and Costs. Beneficial effects of the
proposed projects at October, 1995 prices were determined by
reach and are presented in table E-5. Eight of the plans
evaluated are economically feasible, with B/C ratios ranging from
1.0 to 7.5. A breakdown of cost and benefits and B/C ratio for
the eight feasible plans is given in table E-5. Future benefit
increases above existing conditions are not expected and were not
evaluated. Stream improvements were only justified from the
Railroad spur below US 301 upstream to Goldsboro Street.
Evaluation of the final 3 plans was developed in more detail and
is presented in table E-6. The optimum width for that reach was
found to be 25 feet. The 25-.foot plan for that reach (Plan
HS2512b) is the NED plan and has an overall B/C ratio of 3.0 to
1. The effects of that Plan are discussed in detail in the
section dealing with the NED plan. The detailed analysis is done
in FY96 prices and fully evaluates all benefit categories.
D
E-7
Table E-5. Comparison of Benefits and Costs
Project Average Annual Average Ann Net NED B/C
and Description Ecauival Benefits Costs Benefits Ratio
Plan HRR - Improvements
to Culvert under
CSX Railroad Crossing $ 219,400 $ 28,400
Plan HRR25 - Improvements
to reaches 1-6 with bottom
width of 25 feet $ 806,800
Plan HRR30 - Improvements
to reaches 1-6 with bottom
width of 30 feet $ 834,900
$ 191,000 7.7
$ 161,900 1.3
$ 644,900
$ 125,600 1.2
$ 709,300
Plan HRR35 - Improvements
to reaches 1-6 with bottom
width of 35 feet $ 858,300 $ 766,300 $ 92,000 1.1
Plan HRR40 - Improvements
to reaches 1-6 with bottom
width of 40 feet $ 876,300 $ 852,400 $ 23,900 1.0
Plan HS2512b - Improvements
to parts of reaches 1 and 2 at
a width of 25 feet $ 645,900 $ 215,300 $ 430,600 3.0
Plan HS3012b - Improvements
V Par--is V1 LCCiV
a width of 30 feet $ 661,700 $ 231,100 $ 430,600 2.9
Plan HS3512b - Improvements
to parts of reaches 1 and 2 at
a width of 35 feet $ 677,500 $ 246,800 $ 430,700 2.7
THE NED PLAN
Beneficial Effects. The 25-foot Plan (HS2512b) provides
flood control benefits expected to average 645,900 dollars per
year. Residual flood damages were computed using modified flood
profiles from the hydraulic analyses. Residual flood damages by
category are shown by Reach in table E-4 and by frequency in
table E-7. Only improvements from the Railroad Spur to Park
Avenue were found to be economically justified. The NED plan
will provide significant flood benefits to all categories of
development. A breakdown of benefits by type is given in table
E-8.

Table E-6. Evaluation of Final Plans
Recom Plan
2512b
First Costs 2,401,000
Interest dur Constr 70,000
Financial First Cost 2,471,000
Interest & Amortizatio
Operation & Maint
Total Ave Annual Cost
Ave Annual Benefits
Net Benefits
B/C Ratio

11
193,319
22,000
215,319
645,875
430,557
3.0
35' Plan
to Gldsbro St
2,793,000
81,000
2,874,000
224,847
22,000
246,847
677,504
430,656
2.7

25' Plan
to Raleigh Rd
4,408,000
216,000
4,624,000
361,759
36,000
397,759
687,366
289,607
1.7
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Table E-8 - Existing Average Annual Flood Benefits
Category of Average Annual Percent
Flood Damages Benefits Thous $ of Total
Residential 96.4 15
Commercial 56.8 9
Industrial 439.0 68
Utilities 22.5 4
Transportation 9.1 1
Emergency Costs 22.1 3
Totals 645.9 100
Comparison of Costs and Benefits. Investment costs, average
annual costs, and expected annual benefits are given in table E-9
below. Operation and maintenance costs of $22,000 per year are
expected. The NED plan will provide annual net benefits of
$430,600 and have a B/C ratio of.3.0.
Table E-9. Benefits and Costs of the NED Plan
First Cost
less Relocation Assistance Payments
Adjusted Investment,
add Interest during Construction
Financial First Cost
Average Annual Costs
Interest and Amortization
Operation and Maintenance
Total
Average Annual Benefits
Flood Damage Reduction
Net NED Benefits
B/C Ratio
$2,401,000
0
2,401,000
70,000
$2,471,000
$ 193,300
22,000
$ 215,300
$ 645,900
$ 430,600
3.0
0
•
E-11
APPENDIX F
COST ENGINEERING
The cost estimates for this study were based on a
combination of MCACES (Microcomputer Aided Cost Engineering
System), quotations, and estimates furnished by the Real Estate
Division of Savannah District and other elements of the
Wilmington District. The assumptions that formed the basis for
each category of work are discussed below.
01 LANDS AND DAMAGES
The costs included under this account were provided by the
Real Estate Division. The lands to be acquired are based on a
right-of-way width of 110 feet, which is considered the minimum
desirable to facilitate construction of the improvements,
planting of the trees needed to offset the vegetation that will
be lost during construction, and maintenance of the project.
Contingencies were set at 25 percent as recommended by the Real
Estate Technical Manager.
09 CHANNELS AND CANALS
The costs in this section are based on excavating
approximately 37,000 cy of material from the banks of the stream
with a drag line and hauling the material by truck to a disposal
area that is within 3 miles of the project. Both the portion of
the stream to be widened and the disposal area are accessible
from public roads. Clearing and snagging will be done by the
smallest equipment practical to minimize disturbance to adjacent
vegetation. only brush that can obstruct the flow between the
stream banks and leaning trees that may fall and obstruct flow
will be removed.
F-1
The material excavated from the stream banks will be spread
in the disposal area with a bulldozer. The area will be seeded
after all of the material has been placed. Sediment control
measures as required by the State of North Carolina will be
included in the final plan. The measures included at this stage
include temporary silt fence to remove silt from storm runoff and
construction entrances to remove silt from the tires of the
trucks before they enter public roads. Construction entrances
will also be provided at the locations adjacent to the stream
where trucks will be turning onto public roads.
Slope protection, consisting of filter fabric and riprap,
will be provided at downstream of the Goldsboro street bridge to
control erosion.- Simi lad' slope preter-t-nn ;'xi ll alse be-added at
the CSX rai rod fill. Areas not exposed to high velocities will
be seeded. Erosion control matting will be used on the slopes of
the stream banks.
A 12 foot diameter culvert will be added at the CSX railroad
fill to improve upstream drainage. Installing the culvert by
open cut is unacceptable to the railroad because of the
result; therefore, the culvert will be constructed from tunnel
liner plate which will be assembled as a tunnel advances through
the fill. New headwalls will be constructed at the ends of the
culvert and will be designed to accommodate the existing culvert
which is to remain. Several improvements to small storm drainage
culverts are also included in the plan.
Contingencies were set at 25 percent as recommended by the
table in Appendix D of Engineering Regulation 1110-2-1302. There
were no factors which dictated that a higher or lower rate should
be used.
30 PLANNING, ENGINEERING, AND DESIGN
Costs for preparing the plans and specifications were
furnished by the Chief, Design Section.
F-2
31 CONSTRUCTION MANAGEMENT
Costs for managing the construction contract were furnished
by the Chief, Construction Branch.
r ANNUAL MAINTENANCE
The annual maintenance costs are based on the work being
performed by City of Wilson maintenance crews so that no plans
and specifications or construction management activities would be
required. Also, it was assumed for the purpose of the cost
estimate that the same disposal area or other city-owned property
would be used to dispose of any silt that accumulates in the
stream, so that no additional real estate would be required. All
costs will therefore be in account 09, Channels and Canals.
09 CHANNELS AND CANALS
The maintenance requirements for the project are predicted
to consist of minor amounts of sediment removal and slope
repairs, riprap maintenance consisting of herbicide application
and repositioning of displaced riprap, semiannual mowing, and
replacement of trees that have died. The cleared and snagged
area will need to be inspected and regrowth removed.
Contingencies were set at 25 percent as recommended by the
table in Appendix D of Engineering Regulation 1110-2-1302. The
degree of uncertainty regarding the quantities of each activity
is rather high; however, the quantities selected for the estimate
are fairly conservative so that a larger contingency is not
necessary.

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'State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
MEMORANDUM
A?IFA
DEN R
January 21, 1998
To: Michelle Suverkrubbe
Through: John Dorney
From: Eric Galambo,
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land Use in the watershed varies from rural farmland to highly
urbanized. The middle watershed is urbanized. The lower watershed is mostly rural and
the upper watershed is undergoing a rapid transition from farmland and forest to
residential and commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between Black Creek Road and Tarboro Street.
The COE studied structural and non-structural measures to address the flooding problem.
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofmg were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore and
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8. Therefore, this was a very good day to observe the flooding problem.
Environmental Sciences Branch
Telephone [phone]
• 4401 Reedy Creek Road Raleigh, North Carolina 27607
FAX # [phone]
An Equal opportunity Airimative Action Employer 50% recycled/10% post consumer paper

According to the study, the main flooding problem is the blockage caused by the CSX
railroad causeway just upstream from US 301. Localized flooding occurs upstream of the
project also due to an inadequately sized culvert. The COE has no plans to address the
observed flooding problem upstream of the City Park adjacent to Ripley Road.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE regulations prohibit any increase in the hydrograph. DWQ does not oppose
the installation of an additional culvert. However, the culvert should be designed so that it
is in the dry during normal flow. Otherwise the stream morphology (width to depth ratio)
of the existing channel will be unbalanced resulting in bank erosion, sediment deposition
and other deleterious effects on water quality.
Due to the prohibition of increasing the hydrograph, the COE investigated methods to
TP nra i
i -it, ring jjggkTpll i i7T1 f i ?'rf771 i }r rrriasl .rr is , • ?t _ nnr
b !? a i wtLtii??YG? 1S1cl.LCU UY
as a means to ameliorate the hydrograph. Hominy Swamp is in the Neuse River Basin.
Recently enacted rules (copy sent to Coleman Long and John Badin under separate cover)
prevent the removal of existing riparian forest vegetation in the Neuse basin with a few
narrow exceptions. The rules define forest vegetation as "The plants of an area which
grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street. Forest vegetation is lacking between Phillip Street and
Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Clearing (the removal of
obstructions) would be acceptable. Snagging (the removal of a tree or a part of the tree
that protrudes above the surface in the body of water) may not be acceptable. Rule
NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of individual trees which are in danger
of causing damage to dwellings, other structures or the stream channel. For the portion of
the project that we transversed, we located only one tree that was causing bank erosion
and therefore damage to the stream channel. The Neuse buffer rules would allow for this
individual tree to be removed but would not allow additional snagging.
Due to our rules, the project as proposed would not receive a 401 Water Quality
Certification. COE rules prohibit an increase in the downstream hydrograph. Therefore,
we must revisit acceptable alternatives to reduce the hydrograph and be in compliance
with all rules.
One cannot completely understand the processes that are shaping and influencing a stream
without data collection and interpretation. Dave Rosgen has developed a stream
classification system so that one can extrapolate data and predict process responses
(Rosgen, 1994). Most Federal and State agencies in NC are beginning to use this
AiloWwwwwww-
classification system to solve similar problems with stream flow. The benefit of using
Rosgen's classifications is that one must thoroughly study and understand the stream's
current condition so that it can be matched to its hydrological potential.
Whatever activities are undertaken by the COE, they will be short-lived without
substantial changes in land use development by the City of Wilson. Land use practices
with extensive pavement without design to alleviate these impacts to channels cannot be
mitigated by structural additions or modifications to stream channels (Stream System
Technology Center, 1985). The document states that 297 residences and 45 commercial
buildings are sited in the 100-year floodplain of Hominy Swamp. Last year the City issued
a building permit in the floodplain at Forest Hills Road and Little Hominy Swamp. These
encroachments remove storage capacity of the floodplain, which aggravates the
downstream flooding problem. Recently major commercial and residential construction
has occurred in the watershed. Plazas at the north side of the intersection of Forest Hills
Road and US 264 have been constructed without stormwater detention ponds. The
removal or elimination of land use activities that cause adverse impacts to riparian and
aquatic ecosystems are of the highest priority if restoration is to be accomplished (Stream
System Technology Center, 1985).
The COE indicated during our site visit that the City of Wilson is studying the flooding
problem at Kincaid Avenue. Again due to increased urban development, the culvert at
Kincaid Avenue and Hominy Swamp is probably undersized. The COE has separated this
flooding problem from their project. DWQ believes that these projects must be combined.
The flooding problem at Kincaid Avenue is significant. Therefore, this culvert will most
likely be replaced and the floodwaters backed up by the causeway will move into the
COE's project. Therefore, the COE should account for this additional water.
To ameliorate the flooding problems, alternatives in addition to the City of Wilson
adopting a stormwater management plan for the Hominy Swamp watershed must be
studied. DWQ proposed that the COE study areas where off-line detention ponds could
be constructed. One possible location for a pond would be at the Ridgewood Park off of
Phillip Street. There may be a need for several ponds in the watershed to completely solve
the flooding problem.
Another method to reduce the hydrograph may be to restore or create wetlands in the
watershed. Open land is present at Forest Hills Road and Little Hominy Swamp. Open
land is also present at the upper reaches of Big and Little Hominy Swamp. This work
could be done in conjunction with the Wetland Restoration Program. Mr. Ron Ferrell
should be contacted (919-733-5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration, off-line ponds, retrofitting impervious
areas with stormwater ponds, and upstream dams should be considered in a revised EA.
Please be aware that the Neuse rules have basinwide stormwater requirements (NCAC 2B
.0235) . The City of Wilson is required to submit a model local stormwater management
plan to control nutrients by August 1, 1999. The model plan must address nitrogen
reductions for existing and new development. All new development is to have no net
increase in peak low leaving the site from the predevelopment conditions. The plan must
also find locations for potential stormwater retrofits. These requirements should greatly
assist the COE in reducing the flooding problems in the Hominy Swamp watershed.
Due to the significant issues listed above, DWQ requests that an EIS be written for this
project. The project sponsor is reminded that the 401 Certification would be denied as
currently proposed for reasons described above. Questions regarding the 401
Certification should be directed to Eric Galamb (733-1786) in DWQ s Water Quality Non-
Discharge Branch.
References:
David L. 1994. A Classification of Natural Rivers. Catena (22) pp. 169-199.
Stream ys ?Cent?eerr. October 1985. Artificial Stream Restoration -
Money Well Spent or Fure? St ream Notes.
Cc: Greg Thorpe, DWQ Planning
Owen Anderson, WRC
Howard Hall, USFWS
Ron Ferrell, WRP

JAN 2 i lea}
1l.WmkI rnt-r rrnLL.J L-"I%L-
Hominy Swamp Flood Control 2 January 25, 1998
City of Wilson, 98-E-0368
The project area is within an urbanized area of Wilson. Undeveloped portions of the
upper and middle watershed are undergoing rapid development, which is causing a significant
increase in impervious surf vw that exacerbates flooding problems. On our site visit we
observed what appeared to he recent filling of floodplain areas within this watershed.
The report states that the majority of flooding is caused by a hydraulic restriction at the
CSX railroad crossing. The most significant damage occurs upstream of the railroad crossing.
During our visit we also observed flooding of streets and yards within the floodplain of the creek
upstream of the proposed project. The flooding upstream in a residential subdivision appears to
be due to an undersized culvert at the Kincaid Avenue crossing of Hominy Swamp and the
location of streets immediately adjacent to the stream. However, this area is outside of the
proposed project and it is our understanding that the COE does not plan to consider the impacts
of future removal of this restriction on the downstream project.
The COE proposes to install an additional culvert at the CSX railroad crossing to
alleviate the upstream flooding. However, the additional culvert would increase the downstream
hydrograph by several feet. This is not permitted by COE regulations; therefore, the COE also
proposes to clear and snag the downstream section to Black Creek Road and remove some
sediments from this area and upstream of the CSX crossing to compensate for increasing of the
hydrograph.
The flooding problems and the solutions to flooding problems are closely related to issues
involving comprehensive stormwater management, riparian corridor protection and rules to
prowt, the Neuse River. Therefore, we believe that a more comprehensive review of this project
that includes development and flooding within the entire watershed is warranted. We have the
following recommendations and comments that need to be addressed in the expanded document.
1. As proposed the portion of the project that relates to removal of vegetation along the
stream banks appears to be contrary to rules established by the state to protect the Neuse
River. Therefore, we request that additional alternatives be examined to compensate for
the increase in hydrograph that do not require dredging and removal of woody vegetation.
Creating flood storage in parks and other vacant lots by removal of fill upstream of the
CSX crossing and restoration of wetlands in the watershed are alternatives that should be
evaluated. Alternatives need to be examined in light of new development and stormwater
management for the entire watershed.
2. We believe the problems in Wilson are directly attributable to poor siting of development
within a floodplain. This is somewhat understandable for older structures. However,
there appears to be continuing irresponsible development and filling of floodplains within
the Hominy Swamp Watershed. Any beaefts from the proposed project will be short
lived bccausc the City of Wilson has not demonstrated effective protection of floodplains
and riparian corridors or management of stormwater. Additionally, we believe that the
project will allow for additional development in the watershed in floodplain areas
upstream of the project; and thus, is contrary to the intent of Executive Order 11958.
NCWRC,HCP,FALLS LAKE TEL:[phone] reo 1L-?Ju 0;.Lz no.vvi r.ui+
Hominy Swamp Flood Control 3 January 25,1998
City of Wilson, 98-E-0308
3. The additional culvert installed at tho CSX crossing should not increase the width/depth
ratio of the strown, The additional culvert should be installed at an elevation so that it
will carry the flood flows and would remain dry during normal flows. This will reduce
the amount of maintenance that would be required due to sediment accumulation if
normal flows are spread over both culverts,
4. The increased drainage of upstream areas may have the potential to impact jurisdictional
wetlands by affecting wetland hydrology. The revised environmental document should
include a discussion of any adverse impacts the project would have on wetlands upstream
of the project and how any impacts to wetlands will be mitigated.
5. A comprehensive stormwater management plan that requires stormwater detention ponds
and/or other best management practices (e.g., grass swales instead of curb and gutter)
should be required as part of this project for all development. A prohibition on filling or
development within the 100-year floodplain or within 100=feet of a perennial stream or
termittent stream, which ever is greater, should also be a part of this
project, The d-consider retrofitting stormwater ponds within
existing developed areas to increase . Properly designed ponds
could also provide some water quality benefits.
We appreciate the opportunity to provide input into this project. We look forward to
city of Wilson, the COE and other agencies to find a meaningful, long term
and envirunmenta y 'onto this situation. If we can provide further assistance,
please contact our office at (919) 528-
cc; John I)orney, Division of Water Quality
Howard Hall, USFWS, Raleigh Office
Nt-WKU , ht,r , r hLLJ LnnL ILL-010 .rev JVVJ
Hominy Swamp Flood Control 2 January 25, 1998
City of Wilson, 98-E-0368
The project area is within an urbanized area of Wilson. Undeveloped portions of the
upper and middle watershed are undergoing rapid development, which is causing a significant
increase in impervious surfacrx; that exacerbates flooding problems. On our site visit we
observed what appeared to be recent filling of floodplain areas within this watershed.
The report states that the majority of flooding is caused by a hydraulic restriction at the
CSX railroad crossing. The most significant damage occurs upstream of the railroad crossing.
During our visit we also observed flooding of streets and yards within the floodplain of the creek
upstream of the proposed project. The flooding upstream in a residential subdivision appears to
be due to an undersized culvert at the Kincaid Avenue crossing of Hominy Swamp and the
location of streets immediately adjacent to the stream. However, this area is outside of the
proposed project and it is our understanding that the COE does not plan to consider the impacts
of future removal of this restriction on the downstream project.
The COE proposes to install an additional culvert at the CSX railroad crossing to
alleviate the upstream flooding. However, the additional culvert would increase the downstream
hydrograph by several feet. This is not permitted by COE regulations; therefore, tho COE also
proposes to clear and snag the downstream section to Black Creek Road and remove some
sediments from this area and upstream of the CSX crossing to compensate for increasing of the
hydrograph.
The flooding problems and the solutions to flooding problems are closely related to issues
involving comprehensive stormwater management, riparian corridor protection and rules to
protect the Neuse River. Therefore, we believe that a more comprehensive review of this project
that includes development and flooding within the entire watershed is warranted. We have the
following recommendations and comments that need to be addressed in the expanded document.
1. As proposed the portion of the project that relates to removal of vegetation along the
stream banks appears to be contrary to rules established by the state to protect the Newe
River. Therefore, we request that additional alternatives be examined to compensate for
the increase in hydrograph that do not require dredging and removal of woody vegetation.
Creating flood storage in parks and other vacant lots by removal of fill upstream of the
CSX crossing and restoration of wetlands in the watershed are alternatives that should be
evaluated. Alternatives need to be examined in light of new development and stormwater
management for the entire watershed.
2. We believe the problems in Wilson are directly attributable to poor siting of development
within a floodplain. This is somewhat understandable for older structures. However,
there appears to be continuing irresponsible development and filling of floodplains within
the Hominy Swamp Watershed. Any benefits from the proposed project will be short
lived because the City of Wilson has not demonstrated effective protection of floodplains
and riparian corridors or management of stormwater. Additionally, we believe that the
project will allow for additional developiaeat in the watershed in floodplain areas
upstream of the project; and thus, is contrary to the intent of Executive Order 11988.
NCWRC, HCP , FHLLS LHKE I tt.: 3 P3-.) l tf-y 0J7 r c u 1 G J V V i s na . vv i .vim
Hominy Swamp Flood Control 3 January 25, 1998
City of Wilson, 98-L-0368
3. The additional culvert installed at the CSX crossing should not increase the width/depth
ratio of the stream. The additional culvert should be installed at an elevation so that it
will carry the flood flows and would remain dry during normal flows. This will reduce
the amount of maintenance that would be required due to sediment accumulation if
normal flows are spread over both culverts.
4. The increased drainage of upstream areas may have the potential to impact jurisdictional
wetlands by affecting wetland hydrology. The revised environmental document should
include a discussion of any adverse impacts the project would have on wetlands upstream
of the project and how any impacts to wetlands will be mitigated.
5. A comprehensive stormwater management plan that requires stormwatcr detention ponds
and/or other best management practices (e.g., grass swales instead of curb and gutter)
should be required as part of this project for all development. A prohibition on filling or
with in the 100-year floodplain or within 100-feet of a perennial stream or
velopmat 50-foot o an m e 1 of this
project. The City of Wilson should consider retrofitting stormwater pon s
existing developed areas to increase flood storage capacity. Properly designed ponds
could also provide: some water quality benefits.
fate the opportunity to provide input into this project. We look forward to
working with the City o r s eanin ful, long term
and environmentally acceptable solution to this situation. If we con provide er asMTMV,-
please contact our office at [phone].
cc: John Dorney, Division of Water Quality.
Howard Hall, USFWS, Raleigh Office
-Mate of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
MEMORANDUM
DEN R
January 21, 1998
To: Michelle Suverkrubbe
Through: John Dorney
From: Eric Galambo,
SUBJECT: EA for Flood Damage Reduction at Hominy Swamp
Wilson County
DENR Project No. 98-0368, DWQ No. 11886
This office has reviewed the subject document. The Division of Water Quality (DWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities
which impact waters of the state including wetlands. The Corps of Engineers (COE) is
studying means of addressing the flooding problem along Hominy Swamp at Wilson,
North Carolina. Land Use in the watershed varies from rural farmland to highly
urbanized. The middle watershed is urbanized. The lower watershed is mostly rural and
the upper watershed is undergoing a rapid transition from farmland and forest to
residential and commercial use.
Flood damages in the developed floodplain occur with the 4-year storm event. Eighty
percent of the damages occur between Black Creek Road and Tarboro Street.
The COE studied structural and non-structural measures to address the flooding problem-
Non-structural methods such as structure elevation, floodplain evacuation, flood warning
system and floodproofing were not considered to be practicable. Structural methods such
as an upstream dam, dikes or levees, culvert improvement, channel widening and
deepening, and clearing and snagging were studied.
The COE proposes to perform clearing and snagging, channel widening and deepening,
and culvert improvement. Most of these activities are a concern to DWQ. Therefore and
on-site meeting with the COE, Wildlife Resources Commission (WRC), DWQ and US
Fish and Wildlife Service (USFWS) was held on January 8, 1998. Rain fell January 7 and
8. Therefore, this was a very good day to observe the flooding problem.
Environmental Sciences Branch
Telephone [phone]
• 4401 Reedy Creek Road Raleigh, North Carolina 27607
FAX # [phone]
An EGuof opporfun'ity Affirmative Actlon Employer 50% recycled/10% post consumer paper
`% , - =
According to the study, the main flooding problem is the blockage caused by the CSX
railroad causeway just upstream from US 301. Localized flooding occurs upstream of the
project also due to an inadequately sized culvert. The COE has no plans to address the
observed flooding problem upstream of the City Park adjacent to Ripley Road.
To alleviate the blockage at the railroad, the COE proposes to add another culvert into the
causeway. The additional culvert would increase the downstream hydrograph by several
feet. COE regulations prohibit any increase in the hydrograph. DWQ does not oppose
the installation of an additional culvert. However, the culvert should be designed so that it
is in the dry during normal flow. Otherwise the stream morphology (width to depth ratio)
of the existing channel will be unbalanced resulting in bank erosion, sediment deposition
and other deleterious effects on water quality.
Due to the prohibition of increasing the hydrograph, the COE investigated methods to
reduce it. Clearing and snagging coupled with channel widening was selected by the COE
Recently enacted rules (copy sent to Coleman Long and John Badin under separate cover)
prevent the removal of existing riparian forest vegetation in the Neuse basin with a few
narrow exceptions. The rules define forest vegetation as "The plants of an area which
grow together in disturbed or undisturbed conditions in various wooded plant
communities in any combination of trees, saplings, shrubs, vines and herbaceous plants.
This inrlnrlPC mature and successional forests as well as cutover stands".
Forest vegetation is present from Black Creek Road to Phillip Street, and between Lodge
Street and Goldsboro Street. Forest vegetation is lacking between Phillip Street and
Lodge Street.
DWQ reviewed this project for compliance with the Neuse rules. Clearing (the removal of
obstructions) would be acceptable. Snagging (the removal of a tree or a part of the tree
that protrudes above the surface in the body of water) may not be acceptable. Rule
NCAC 2B .0233 (3)(a)(ii)(D) permits the removal of individual trees which are in danger
of causing damage to dwellings, other structures or the stream channel. For the portion of
the project that we transversed, we located only one tree that was causing bank erosion
and therefore damage to the stream channel. The Neuse buffer rules would allow for this
individual tree to be removed but would not allow additional snagging.
Due to our rules, the project as proposed would not receive a 401 Water Quality
Certification. COE rules prohibit an increase in the downstream hydrograph. Therefore,
we must revisit acceptable alternatives to reduce the hydrograph and be in compliance
with all rules.
One cannot completely understand the processes that are shaping and influencing a stream
without data collection and interpretation. Dave Rosgen has developed a stream
classification system so that one can extrapolate data and predict process responses
(Rosgen, 1994). Most Federal and State agencies in NC are beginning to use this

classification system to solve similar problems with stream flow. The benefit of using
Rosgen's classifications is that one must thoroughly study and understand the stream's
current condition so that it can be matched to its hydrological potential.
Whatever activities are undertaken by the COE, they will be short-lived without
substantial changes in land use development by the City of Wilson. Land use practices
with extensive pavement without design to alleviate these impacts to channels cannot be
mitigated by structural additions or modifications to stream channels (Stream System
Technology Center, 1985). The document states that 297 residences and 45 commercial
buildings are sited in the 100-year floodplain of Hominy Swamp. Last year the City issued
a building permit in the floodplain at Forest Hills Road and Little Hominy Swamp. These
encroachments remove storage capacity of the floodplain, which aggravates the
downstream flooding problem. Recently major commercial and residential construction
has occurred in the watershed. Plazas at the north side of the intersection of Forest Hills
Road and US 264 have been constructed without stormwater detention ponds. The
removal or elimination of land use activities that cause adverse impacts to riparian and
aquatic ecosystems are of the highest priority if restoration is to be accomplished (Stream
System Technology Center, 1985).
The COE indicated during our site visit that the City of Wilson is studying the flooding
problem at Kincaid Avenue. Again due to increased urban development, the culvert at
Kincaid Avenue and Hominy Swamp is probably undersized. The COE has separated this
flooding problem from their project. DWQ believes that these projects must be combined.
The flooding problem at Kincaid Avenue is significant. Therefore, this culvert will most
likely be replaced and the floodwaters backed up by the causeway will move into the
COE's project. Therefore, the COE should account for this additional water.
To ameliorate the flooding problems, alternatives in addition to the City of Wilson
adopting a stormwater management plan for the Hominy Swamp watershed must be
studied. DWQ proposed that the COE study areas where off-line detention ponds could
be constructed. One possible location for a pond would be at the Ridgewood Park off of
Phillip Street. There may be a need for several ponds in the watershed to completely solve
the flooding problem.
Another method to reduce the hydrograph may be to restore or create wetlands in the
watershed. Open land is present at Forest Hills Road and Little Hominy Swamp. Open
land is also present at the upper reaches of Big and Little Hominy Swamp. This work
could be done in conjunction with the Wetland Restoration Program Mr. Ron Ferrell
should be contacted (919-733-5083) for additional information.
Instream dams may be acceptable if the watershed is less than 400 acres and wetland
impacts are minimized. These ponds probably cannot solve the downstream flooding.
However, a combination of wetland restoration, off-line ponds, retrofitting impervious
areas with stormwater ponds, and upstream dams should be considered in a revised EA.
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'* NC_NRC,HCP,FALLS LAKE TEL:[phone] Feb 12'98 8:10 No.001 P.02
® North Carolina Wildlife Resources Commission.
512 N. saliabury Street, Raleigh, North Carolina 27604-1188, 919-7333391
Charles R. Fullwood, Fmcutive Director
MEMORANDUM
TO: Melba McGee, Environmental Coordinator
Office of Legislative and Inter ovewr=etxtal airs
From: Owen F. Anderson, Piedmont Region Coordinator
Habitat Conservation Program
Date: January 25, 1998
Subject; Detailed Project Report and Environmental Assessmotit on Flood Damage
Reduction, hominy Swamp, City of Wilson, Wilson County, N(, 98-E-0368
Staff' biologists with North Catolim Wildlife Resources Commission have reviewed the
proposed project and arc familiar with habitat values of the area. We have made visits to the area
on several occasions. Most recently (January 8, 1998), we met with the Corps of Engineers
(COL), the Division of Water Quality and the U.S. Fish and Wildlife Service on-site to discuss
and further cvaluatc the project. Our site visit was made after and during storm events that
provided an opportunity to observe the creek at an elevated stage. Our comments are provided in
accordance with provisions of National Environmental Policy Act (42 U.S.C 4332(2)(c)), the
f=ish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C 661-6674), and this
North Carolina Environmental Policy Act (G.S. 113A-1 through 113A-10; 1 NCAC 25).
We generally agree with the assessIneot and description of the habitat in the areas. We
acknowledge that there are flooding problems in the area. Some flood damage occurs with
approximately a four-year storm event. We are concerned that the project as proposed has the
potential to lead to future flood control projects that may have more significant adverse impacts
on fish and wildlife habitat.
NCWRC,HCP,FALLS LAKE TEL:[phone] Feb 12'98 8:11 No.001 P.03
Hominy Swamp Flood Control 2 January 25, 1998
City of Wilson, 98-E-0368
The project area is within an urbanized area of Wilson. Undeveloped portions of the
upper and middle watershed arc undorgoing rapid development, which is causing a significant
increase in impervious surf4 -v4 that exacerbates flooding problems. On our site visit we
observed what appeared to he recent filling of floodplain areas within this watershed.
The report states that the majority of flooding is caused by a hydraulic restriction at the
CSX railroad crossing. The most si0ficant damage occurs upstream of the railroad crossing.
During our visit we also observed flooding of streets and yards within the floodplain of the creek
upstream of the proposed project. The flooding upstream in a residential subdivision appears to
be due to an undersized culvert at the Kincaid Avenue crossing of Hominy Swamp and the
location of streets immediately adjacent to the stream. However. this area is outside of the
proposed project and it is our understanding that the COE does not plan to consider the impacts
of future removal of this restriction on the downstream project.
The COE proposes to install an additional culvert at the CSX railroad crossing to
alleviate the upstream flooding. However, the additional culvert would increase the downstream
hydrograph by several feet. This is not permitted by COE regulations, therefore, the COE also
proposes to clear and snag the downstream section to Black Creek Road and remove some
sediments from this area and upstream of the CSX crossing to compensate for increasing of the
hydrograph.
The flooding problems and the solutions to flooding problems are closely related to issues
involving comprehensive stormwater management, riparian corridor protection and rules to
protect the Neuse River. Therefore, we believe that a more comprehensive review of this project
that includes development and flooding within the entire watershed is warranted. We have the
fallowing recommendations and comments that need to be addressed in the, expanded document.
1. As proposed the portion of the project that relates to removal of vegetation along the
stream banks appears to be contrary to rules established by the state to protect the Neuse
River. Therefore, we request that additional alternatives be examined to compensate for
the increase in hydrograph that do not require dredging and removal of woody vegetation,
Creating flood storage in parks and other vacant lots by removal of fill upstream of the
CSX crossing and restoration of wetlands in the watershed are alternatives that should be
evaluated. Alternatives need to be examined in light of new development and stormwater
management for the entire watershed.
2. We believe the problems in Wilson are directly attributable to poor siting of development
within a floodplain. This is somewhat understandable for older structures. However,
there appears to be continuing, irresponsible development and filling of flood plains within
the Hominy Swamp Watershed, Any benefits from the proposed project will be short
lived bccausc the City of Wilson has not demonstrated affective protection of floodplains
and riparian corridors or management ofstormwater. Additionally, we believe that the
project will allow for additional development in the watershed in toodplain areas
upstream of the project; and thus, is contrary to the intera of Executive Order 11988.
NtWRC,HCP,FALLS LAKE TEL:[phone] Feb 12'98 8:12 No.001 P.04
Hominy Swamp Flood Control 3 January 25, 1998
City of Wilson, 98-E-0368
3. The additional culvert installed at the CSX crossing should not increase the width/depth
ratio of the stream, The additional culvert should bo installed at an elevation so that it
will carry the flood flows and would remain dry during normal flows. This will reduce
the amount of maintenance that would be required due to sediment accumulation if
normal flows are spread over both culverts,
4. The increased drainage of upstream areas may have the potential to impact jurisdictional
wetlands by affecting wetland hydrology. The revised environmental document should
include a discussion of any adverse impacts the project would have on wetlands upstream
of the project and how any impacts to wetlands will be mitigated.
A comprehensive stormwater management plan that requires stormwatcr detention ponds
and/or other best management practices (e.g., grass swales instead of curb and gutter)
should be required as part of this project for all development. A prohibition on filling or
development within the 100-year floodplain of within 100-feet of a perennial stream or
50-foot of an intermittent stream, which ever is greater, should also be a part of this
project, The City of Wilson should consider retrofitting stormwater ponds within
existing developed areas to increase flood storage capacity. Properly designed ponds
could also provide: some water quality benefits.
We appreciate the opportunity to provide input into this project, We look forward to
working with the City of Wilson, the COE and other agencies to find a meaningful, long term
and environmentally acceptable solution to this situation. If we can provide further assistance,
please contact our office at [phone].
cc; John I)orney, Division of Water Quality
Howard Hall, USFWS, Raleigh Office
' NCWRC,HCP,FALLS LAKE TEL:[phone] Feb 12'98 8:10 No.001 P.01
NC Wildlife Resources Commission
OVER Habitat Conservation Programs
FAX [phone] Service Road
FaIIS Lake Office Creedmoor, NC 27522
Date 2.ri2- 17
Number or pace$ including cover sheet
To:
Phane
M .Fex Phone
M.
?j y1r
From:
Phot a 919-528.9336
Fax Phane 91°-523-9E3°
Urgent C, Far your review [] Reply ASAP r r peace corrrient
NOTE- NEW US POSTAL MAILING ADO.RESS: 1142-1-85 SERVICE ROAD
CREEDMOOR, NC 27522
NCWRC,HCP,FALLS LAKE
TEL:[phone]
FAX COVER
f=alls Lake Office
DZte 1-9 -4;,
Numoee of P80es inCiudina cover she4t
To:
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CC:

Jan 09'98
13:04 No. 006 P.01
NC Wildlife Resources Commission
Habitat Conservation Program
1942 f-85 Service Road
Creedmoor, NC 27522
From:
Phone 91Q-528.5386
Fax FFcnE 9't?-5z8.gg;?
? ^y r'.p. - :yam r•:
F^r your review D F,=piy AS
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NOTE: NEW US POSTAL MAILING ADDRESS: 1142 1-85 SERVICE ROAD
CREEDMOOR, NC 2.7522
NCWRC,HCP,FALLS LAKE TEL:[phone] Jan 09'98 13:04 No.006 P.02

MEMORANDUM
TO
From:
Date ;
Subject:
L.K. Gantt, Supervising BiolQgist
U.B. Fish and Wildlife Service
Franklin T. McBride, Program Manager
Habitat Conservation Program
October 23, 1995
Draft Hominy Swamp Flood Control Project, City of
Wilson, Wilson County, KC
Staff biologists with North Carolina Wildlife Resources
Commission have reviewed the proposed project and are familiar
with habitat values of the area. our comments are provided in
accordance with provisions of the Fish and Wildlife Coordination
Act (49 Stat. 401, as amendedi U.S.G. 661 et seq_).
We generally agree with the U.S. Fish and Wildlife Services
assessment of the project's fish and wildlife habitat.values and
the numerous adverse environmental impacts that will result from
the project. While we agree with and support the five
recommendations for minimizing impacts of the project, we do not
believe these will provide sufficient mitigation for the impacts.
Based on the information in the document, we are unable to reach
the conclusion that project impacts will be insignificant.
We cannot concur with the project as described for the
following reasons
1. This project was initially authorized in 1966, Flooding
does not appear to have been a problem during the years
oince the authorization of the, project and there ie no
discussion or analysis of flooding problems in the document,
Considering the recent problems with water quality in the
lower Meuse River, we do not believe it prudent to address
urban runoff by channelizatiQn. To prevea.t further declines
in water quality in the Neuse River Basin, we believe that
resources would be better spent and the public better served
NCWRC,HCP,FALLS LAKE TEL:[phone] Jan 09'98 13:05 No.006 P.03
Hominy Swamp Flood Control 2 October 23, 1995
City of Wilson
by dealing with stormwater at its source. A number of USFWS
recommendations (page 5) were made in a report dated July
14, 1987; however, there is no discussion of which of these
measures have been implemented by the city of Wilson.
2. This channelization will drain riparian and floodplain areas
and reduce water storage. There is no discussion in the
document concerning the impacts of this project on wetlands.
If water storage and water tables are reduced, any
associated wetlands in the area would be adversely impacted.
Loss of floodplain areas and associated wetlands will
adversely affect wildlife and water quality.
3. Increased sediment, water velocities, and nutrients will
negatively affect Contentnea creek and only exacerbate the
problems in the lower Neuae River.
4. There are no plans for floodplain development restrictions
along the creek. Without floodplain restrictions,
additional development will occur and escalate flooding
problems. This project could lead to additional flood
control projects (page 15), that would cause further
destruction of habitat and degradation of water quality.
We recommend that the City of Wilson address flooding
problems by proactive measures such as implementation of
stoxmwater management practices (e.g. wet retention ponds,
grassed swales, sheet flow, and density restrictions) to address
urban runoff at the source. Protection of riparian areas and
floodplains along streams and establishment of forested buffers
where they are lacking will also help in water storage; and thus,
reduce flooding from rapid runoff. Restrictions on development
in floodplains and wetlands should be implemented and strictly
enforced. Protection of upstream segments in headwater areas
should be given a high priority.
We appreciate the opportunity to provide input into this
project. If we can provide further assistance, please contact
our office at [phone].
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
tAlt 0
!?V ??
ED EHN F1
December 22, 1997
Mr. James H. Bradley
COE
PO Box 1890
Wilmington, NC 28402-1890
Dear Mr. Bradley:
Re: 401 Water Quality Certification
Homing Swamp Dredging
Wilson County
DWQ #971044
On December 1, 1997 you wrote to the Division of Water Quality (DWQ) requesting a
401 Water Quality Certification for your project to impact waters for dredging at Homing
Swamp in Wilson County. We believe that this project is currently under review by they
State Clearinghouse. DWQ cannot issue the 401 Certification until the project has received
a Finding of No Significant Impact (FONSI) or Record of Decision (ROD) from the State
Clearinghouse in accordance with NCAC 15A: 01C.0402. Therefore, I must hereby place
this project on indefinite hold until the State Clearinghouse has issued the FONSI or ROD.
However we will continue to review the project and make you aware of any concerns. We
recommend that you notify us that the NEPA/SEPA process is complete so we can
reactivate the project. In addition, by copy of this letter, I am also notifying the U.S. Army
Corps of Engineers that this project should be placed on hold.
If you believe that this decision is in error, please call me at 919-733-1786 to discuss
the matter.
Sincerely,
PaterQuality y
Cert' is i on Program
-cc: --Raleigh DWQ Regional Office
U.S. Army Corps of Engineers Wilmington District Office
Central Files
971044.nocert
Division of Water Quality - Environmental Sciences Branch
4401 Reedy Creek Rd., Raleigh, NC 27626-0535 *Telephone [phone] - FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
- ? 1
TRIAGE CHECKLIST
Project Name:
Project Number: l I
County: i?st
II d,4 ,i
FILE COPY
The attached project has been sent to you for review for the following reasons. Please consider whether a
site visit is needed to determine the impacts. Particular attention should focus on the below checked items.
Please feel free to call the central office staff member assigned to your region if you need assistance.
Stream length impacted.
- Stream determination (i.e. intermittent or perennial, or any channel present).
Wetland impact and distance to blue-line surface waters on USGS topo map.
Minimization/avoidance options.
NW 14. (is access to highground or wetlands)?
Neuse buffer rules.
Pond (water) fill (i.e. is the pond drained or holding water)?
Pond creation (i.e. in uplands, in a drained channel, or in wetlands). Please locate streams and
channels (if any) so that the central office can determine.
Mitigation ratios.
- Stormwater pond placed in wetlands.
Ditching in wetlands.
Is the applicant's proposed stream/wetland mitigation site available and viable?
Applicant/consultant has a history of non-compliance (check drawings and application for
accuracy).
Has project been split from previous work to avoid mitigation requirements'?
- Consistent with pre-application meetings?
- Cumulative impact concerns.
OTHER:

w
971®44
U.S. ARMY CORPS OF ENGINEERS
APPLICATION FOR 401 WATER QUALITY CERTIFICATION
STATE OF NORTH CAROLINA
1. DATE: November 21, 1997
2. NAME/ADDRESS OF AGENT: U.S. Army Corps of Engineers
Wilmington District
Post Office Box 1890
Wilmington, North Carolina 28402-1890
3. RESPONSIBLE INDIVIDUAL: Terry R. Youngbluth
Colonel, U.S. Army
District Engineer
4. NAME OF CORPS OF ENGINEERS CONTACT: John A. Baden
TELEPHONE NUMBER: [phone]
5. TYPE OF APPLICATION: New Application
6. PROJECT NAME: Hominy Swamp
Flood Damage Reduction Project
City of Wilson, North Carolina
7. DESCRIPTION OF PROPOSED WORK: The recommended plan consists of
various channel improvements or clearing and snagging over the project length of
approximately 2.1 miles. Beginning at the downstream end, clearing and snagging will
extend from the bridge at Black Creek Road upstream approximately 0.9 miles to the
trestle on a railroad spur line. From this railroad spur line upstream to Goldsboro
Street, a reach of approximately 1.2 miles will be widened to 25 feet with side slopes of
1 horizontal to 1 vertical. Approximately 40,000 cubic yards of material will be removed
and transported to an upland disposal area. A 12-foot-diameter culvert will be bored
and jacked through the fill under the CSX railroad main line. A total volume of about
150 cubic yards of riprap will be needed for erosion control of the new culvert. The
work will be performed as described in the following document:
led Proiect Report and Envi
om
aroiina
on Flood Damaae
8. PURPOSE OF PROPOSED WORK: Reduction of urban flooding within the city of
Wilson.
9. PROPOSED ACTIVITY TO BEGIN: 2002.
?. Y
10. DURATION OF ACTIVITY: Approximately one year
11. DISCHARGE OF: Approximately 40,000 cubic yards of material will be removed
and transported to a disposal area for channel widening. There will be a minimum
amount of material discharged back into the stream in association with widening of the
channel and placement of the culvert.
12. LOCATION OF DISCHARGE: See 11, above.
Municipality: city of Wilson
County: Wilson
Drainage Basin: Neuse River
Receiving Waters: Hominy Swamp
13. NATURE OF RECEIVING WATERS:
Type: Riverine
Nature: Fresh
Direction of Flow: Downstream
14. TYPE OF DISCHARGE INCLUDING CHEMICAL COMPOSITION: Material
incidental to construction.
15. PROJECTED FUTURE VARIATION IN THE NATURE OF THE DISCHARGE:
Placement of culvert is a one-time event. Periodic maintenance of the project may
involve discharge of an insignificant amount of material in the stream.
16. IS THIS PROJECT LOCATED IN A WATERSHED CLASSIFIED AS SA. HOW
nQ nC1A/7
- YES x NO
17. NUMBER OF ACRES OR VOLUME OF WETLANDS IMPACTED BY THE
PROPOSED ACTION:
Excavated: Reference 14, above.
Filled: Reference 14, above.
18. STATE REASON WHY THE APPLICANT BELIEVES THAT THIS ACTIVITY
MUST BE CARRIED OUT AS PLANNED. ALSO NOTE MEASURES TAKEN TO
MINIMIZE WETLAND IMPACTS: Reference 7, 8, and 17, above. Channel
modifications were considered for Hominy Swamp over a distance of about 26,800 feet.
Besides the no-action alternative, the selected proposed action gave the greatest
benefit to both the town and the environment.
2

19.
FO
YES
x NO
N 401 C
FICATES BEEN PREVIOUSLY R
I certify that all information contained herein or in support thereof is true and
correct to the best of my knowledge.
J es H. Bradley, P.E.
ief, Technical Services Division
Attachment
Date:
3
U.S. ARMY CORPS OF ENGINEERS
APPLICATION FOR 401 WATER QUALITY CERTIFICATION
STATE OF NORTH CAROLINA
1. DATE: November 21, 1997
2. NAME/ADDRESS OF AGENT: U.S. Army Corps of Engineers
Wilmington District
Post Office Box 1890
Wilmington, North Carolina 28402-1890
3. RESPONSIBLE INDIVIDUAL: Terry R. Youngbluth
Colonel, U.S. Army
District Engineer
4. NAME OF CORPS OF ENGINEERS CONTACT: John A. Baden
TELEPHONE NUMBER: [phone]
5. TYPE OF APPLICATION: New Application
6. PROJECT NAME: Hominy Swamp
Flood Damage Reduction Project
City of Wilson, North Carolina
7. DESCRIPTION OF PROPOSED WORK: The recommended plan consists of
various channel improvements or clearing and snagging over the project length of
approximately 2.1 miles. Beginning at the downstream end, clearing and snagging will
extend from the bridge at Black Creek Road upstream approximately 0.9 miles to the
trestle on a railroad spur line. From this railroad spur line upstream to Goldsboro
Street, a reach of approximately 1.2 miles will be widened to 25 feet with side slopes of
1 horizontal to 1 vertical. Approximately 40,000 cubic yards of material will be removed
and transported to an upland disposal area. A 12-foot-diameter culvert will be bored
and jacked through the fill under the CSX railroad main line. A total volume of about
150 cubic yards of riprap will be needed for erosion control of the new culvert. The
work will be performed as described in the following document:
on Flood Damaae Reduction
8. PURPOSE OF PROPOSED WORK: Reduction of urban flooding within the city of
Wilson.
9. PROPOSED ACTIVITY TO BEGIN: 2002.
10. DURATION OF ACTIVITY: Approximately one year.
11. DISCHARGE OF: Approximately 40,000 cubic yards of material will be removed
and transported to a disposal area for channel widening. There will be a minimum
amount of material discharged back into the stream in association with widening of the
channel and placement of the culvert.
12. LOCATION OF DISCHARGE: Seel 1, above.
Municipality: city of Wilson
County: Wilson
Drainage Basin: Neuse River
Receiving Waters: Hominy Swamp
13. NATURE OF RECEIVING WATERS:
Type: Riverine
Nature: Fresh
Direction of Flow: Downstream
14. TYPE OF DISCHARGE INCLUDING CHEMICAL COMPOSITION: Material
incidental to construction.
15. PROJECTED FUTURE VARIATION IN THE NATURE OF THE DISCHARGE:
Placement of culvert is a one-time event. Periodic maintenance of the project may
involve discharge of an insignificant amount of material in the stream.
16. IS THIS PROJECT LOCATED IN A WATERSHED CLAS
/1n r%r%%A/A
_ YES x NO
17. NUMBER OF ACRES OR VOLUME
nn^n^cIITn AnT1r%h1.
Excavated: Reference 14, above.
Filled: Reference 14, above.
18. STATE REASON WHY THE APPLICANT BELIEVES THAT THIS ACTIVITY
MUST BE CARRIED OUT AS PLANNED. ALSO, NOTE MEASURES TAKEN TO
MINIMIZE WETLAND IMPACTS: Reference 7, 8, and 17, above. Channel
modifications were considered for Hominy Swamp over a distance of about 26,800 feet.
Besides the no-action alternative, the selected proposed action gave the greatest
benefit to both the town and the environment.
2
19. HAVE
YES
x NO
Y REQUESTED
I certify that all information contained herein or in support thereof is true and
correct to the best of my knowledge.
J es H. Bradley, P.E.
ief, Technical Services Division
Date:
Attachment
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
P.O. BOX 1890
WILMINGTON, NORTH CAROLINA 28402-1890
IN REPLY REFER TO November 21, 1997
Environmental Resources Section
?? OF
Mr. John Dorney
Division of Water Quality
North Carolina Department of Environment,
Health, and Natural Resources
4401 Reedy Creek Road
Raleigh, North Carolina 27626-1786
Dear Mr. Dorney: 9 j-10 4 4
Under the authority of Section 205 of the 1948 Flood Control Act, as amended,
the U.S. Army Corps of Engineers, Wilmington District, has completed the enclosed
Detailed Proiect Resort and Environmental Assessment on Flood Damaae
Reduction, Hominy Swamp, City of Wilson, North Carolina, dated October 1997.
This study was conducted to address the flooding along Hominy Swamp at the city of
Wilson, North Carolina. Pursuant to the Memorandum of Agreement (MOA) between
your Division and the U.S. Army Corps of Engineers, Wilmington District, a draft
application for a 401 Water Quality Certificate is also enclosed for your review.
As stated in the MOA, there will be a 30-day review and comment period for this
project, at which time the Division of Water Quality will furnish the Wilmington
District a statement regarding the status of the request for 401 Water Quality
Certification.
If you have any questions concerning this matter, please contact
Mr. John A. Baden, Environmental Resources Section, at [phone].
Sincerely,
J mes H. Bradley, P.E.
hief, Technical Servic ivision
Enclosures