20051545 Ver 1_Complete File_20050811

.
t
PROGRAM
August 11, 2005
AUG 1 1 2005
Cyndi Karoly, Unit Supervisor
Division of Water Quality
401 Wetlands Unit
1650 Mail Service Center
Raleigh, NC 27699 - 1650
Sincerely
Re: Permit Application- Caldwell Station Creek and Associated Floodplain Stream and
Wetland Restoration Project
Dear Ms. Karoly:
Attached for your review are two copies of restoration plans (one copy sent to DWQ Mooresville
Regional Office) for Caldwell Station Creek stream and wetland enhancement/restoration project
in Mecklenburg County. Please feel free to contact me with any questions regarding this plan
(715-7571).
Thank you very much for your assistance.

p@[Empm P
DENR - WATER QUALITY
1"OLANDS AND STOWA ATER BRANCH
Lin Xu
Attachment: Caldwell Station Creek Restoration Plan (2 originals)
forth Carolina Ecosystem Enhancement Program., 1652 Mail Service Center, Ra
.1
eigh
NC 2169!
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7
?-1652 / 919-71S-0176 / tvww.nceep.net
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Office Use Only: Form Version October 2001
USACE Action ID No. D`VQ No.
If any particular item is not applicable to this project, please enter "Not Applicable" or "N/A" rather than
leaving the space blank.
1. Processing
1. Check all of the approval(s) requested for this project:
® Section 404 Permit
? Section 10 Permit
® 401 Water Quality Certification
? Riparian or Watershed Buffer Rules
2. Nationwide, Regional or General Permit Number(s) Requested: Nationwide 27
3. If this notification is solely a courtesy copy because written approval for the 401 Certification
is not required, check here: ?
4. If payment into the North Carolina Wetlands Restoration Program (NCWRP) is proposed for
mitigation of impacts (see section VIII - Mitigation), check here: /;Z, V D
u `/ D
II. Applicant Information AUG 1 1 2005
1. Owner/Applicant Information DENR - WATER QUALITY
Name: NC Ecosystem Enhancement Program "EETMOS AND STORliWATER 8MNC1i
Mailing Address: 1652 Mail Service Center Raleigh, NC 27699-1652
Telephone Number: 919-715-7571 Fax Number: 919-715-2219
E-mail Address: lin.xunncmail.net
2. Agent Information (A signed and dated copy of the Agent Authorization letter must be
attached if the Agent has signatory authority for the owner/applicant.)
Name: N/A
Company Affiliation: N/A
Mailing Address: N/A
Telephone Number: N/A
E-mail Address: N/A
Fax Number: N/A
Page 5 of 13
III. Project Information
Attach a vicinity map clearly showing the location of the property with respect to local
landmarks such as towns, rivers, and roads. Also provide a detailed site plan showing property
boundaries and development plans in relation to surrounding properties. Both the vicinity map
and site plan must include a scale and north arrow. The specific footprints of all buildings,
impervious surfaces, or other facilities must be included. If possible, the maps and plans should
include the appropriate USGS Topographic Quad Map and NRCS Soil Survey with the property
boundaries outlined. Plan drawings, or other maps may be included at the applicant's discretion,
so long as the property is clearly defined. For administrative and distribution purposes, the
USACE requires information to be submitted on sheets no larger than 11 by 17-inch format;
however, DWQ may accept paperwork of any size. DWQ prefers full-size construction
drawings rather than a sequential sheet version of the full-size plans. If full-size plans are
reduced to a small scale such that the final version is illegible, the applicant will be informed that
the project has been placed on hold until decipherable maps are provided.
1. Name of project: Caldwell Station Creek and Associated Floodplain Wetlandv Restoration
Proiect
2. T.I.P. Project Number or State Project Number (NCDOT Only): N/A
3. Property Identification Number (Tax PIN): N/A
4. Location
County: Mecklenburg Nearest Town: Cornelius
Subdivision name (include phase/lot number): N/A
Directions to site (include road numbers, landmarks, etc.): The restoration tracts are located
to the east of SR 21 approximately 2,000 feet north of the intersection of SR 21 and Sam
Furr Road in northern Mecklenburg County, North Carolina, south of the township of
Cornelius.
5. Site coordinates, if available (UTM or Lat/Long): N/A
(Note - If project is linear, such as a road or utility line, attach a sheet that separately lists the
coordinates for each crossing of a distinct waterbody.)
6. Describe the existing land use or condition of the site at the time of this application:
Residential and commercial development
7. Property size (acres): 1,523 acres
Nearest body of water (stream/river/sound/ocean/lake): Caldwell Station Creek and
McDowell Creek
9. River Basin: Catawba
(Note - this must be one of North Carolina's seventeen designated major river basins. The
River Basin map is available at http://h2o.enr.state.nc.us/adniin/maps/.)
Page 6 of 13
10. Describe the purpose of the proposed work: Stream enhancement and restoration, wetland
enhancement, preservation, and restoration
11. List the type of equipment to be used to construct the project: Track Hoes, loaders
12. Describe the land use in the vicinity of this project: Residential and commercial
development
IV. Prior Project History
If jurisdictional determinations and/or permits have been requested and/or obtained for this
project (including all prior phases of the same subdivision) in the past, please explain. Include
the USACE Action ID Number, DWQ Project Number, application date, and date permits and
certifications were issued or withdrawn. Provide photocopies of previously issued permits,
certifications or other useful information. Describe previously approved wetland, stream and
buffer impacts, along with associated mitigation (where applicable). If this is a NCDOT project,
list and describe permits issued for prior segments of the same T.I.P. project, along with
construction schedules.
N/A
V. Future Project Plans
Are any future permit requests anticipated for this project? If so, describe the anticipated work,
and provide justification for the exclusion of this work from the current application:
N/A
VI. Proposed Impacts to Waters of the United States/Waters of the State
It is the applicant's (or agent's) responsibility to determine, delineate and map all impacts to
wetlands, open water, and stream channels associated with the project. The applicant must also
provide justification for these impacts in Section VII below. All proposed impacts, permanent
and temporary, must be listed herein, and must be clearly identifiable on an accompanying site
plan. All wetlands and waters, and all streams (intermittent and perennial) must be shown on a
delineation map, whether or not impacts are proposed to these systems. Wetland and stream
evaluation and delineation forms should be included as appropriate. Photographs may be
included at the applicant's discretion. If this proposed impact is strictly for wetland or stream
mitigation, list and describe the impact in Section VIII below. If additional space is needed for
listing or description, please attach a separate sheet.
Page 7 of 13
1. Wetland Impacts
Wetland Impact
Site Number
(indicate on ma)
Type of Impact* Area of
Impact
(acres) Located within
100-year Floodplain**
(yes/no) Distance to
Nearest Stream
(linear feet)
Type of Wetland***

Tributary # 1 Grading and
earthwork to
restore streams
0.15
No
160
Bottomland Hardwood

* List each impact separately and identify temporary impacts. Impacts include, but are not limited to: mechanized clearing, grading, fill,
excavation, flooding, ditch ing/drainage, etc. For dams, separately list impacts due to both structure and flooding.
** 100-Year floodplains are identified through the Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Maps
(FIRM), or FEMA-approved local floodplain maps. Maps are available through the FEMA Map Service Center at 1-800-358-9616, or
online at htln://www.fcma.eov.
*** List a wetland type that best describes wetland to be impacted (e.g., freshwater/saltwater marsh, forested wetland, beaver pond,
Carolina Bay, bog, etc.)
List the total acreage (estimated) of existing wetlands on the property: 7.3 acres
Total area of wetland impact proposed: 0.15 acres
2. Stream Impacts, including all intermittent and perennial streams
Stream Impact
Site Number
(indicate on ma)
Type of Impact* Length of
Impact
(linear feet)
Stream Name** Average Width
of Stream
Before Impact Perennial or
Intermittent?
(please secif )

Tributary #I Grading and
earthwork to
restore existing
180
Tributary # 1
23.5 feet
Perennial

* List each impact separately and identify temporary impacts. Impacts include, but are not limited to: culverts and associated rip-rap,
dams (separately list impacts due to both structure and flooding), relocation (include linear feet before and after, and net loss/gain),
stabilization activities (cement wall, rip-rap, crib wall, gabions, etc.), excavation, ditching/straightening, etc. If stream relocation is
proposed, plans and profiles showing the linear footprint for both the original and relocated streams must be included.
** Stream names can be found on USGS topographic maps. If a stream has no name, list as UT (unnamed tributary) to the nearest
downstream named stream into which it flows. USGS maps are available through the USGS at 1-800-358-9616, or online at
www.uses.goy. Several internet sites also allow direct download and printing of USGS maps (e.g., www.lopozone.com,
www.mapquest.com, etc.).
Cumulative impacts (linear distance in feet) to all streams on site: 180 LF
Page 8 of 13
3. Open Water Impacts, including Lakes, Ponds, Estuaries, Sounds, Atlantic Ocean and any
other Water of the U.S. (No Impact)
Open Water Impact
Site Number
(indicate on ma)
Type of Impact* Area of
Impact
(acres) Name Waterbody
)
(if applicable) Type of Waterbody
(lake, pond, estuary, sound,
bay, ocean, etc.)

* List each impact separately and identify temporary impacts. Impacts include, but are not limited to: till, excavation, dredging,
flooding, drainage, bulkheads, etc.
4. Pond Creation
If construction of a pond is proposed, associated wetland and stream impacts should be
included above in the wetland and stream impact sections. Also, the proposed pond should
be described here and illustrated on any maps included with this application.
Pond to be created in (check all that apply): ? uplands ? stream ? wetlands
Describe the method of construction (e.g., dam/embankment, excavation, installation of
draw-down valve or spillway, etc.): N/A
Proposed use or purpose of pond (e.g., livestock watering, irrigation, aesthetic, trout pond,
local stormwater requirement, etc.): N/A
Size of watershed draining to pond: N//A Expected pond surface area: N/A
VII. Impact Justification (Avoidance and Minimization)
Specifically describe measures taken to avoid the proposed impacts. It may be useful to provide
information related to site constraints such as topography, building ordinances, accessibility, and
financial viability of the project. The applicant may attach drawings of alternative, lower-impact
site layouts, and explain why these design options were not feasible. Also discuss how impacts
were minimized once the desired site plan was developed. If applicable, discuss construction
techniques to be followed during construction to reduce impacts.
The nroiect is involved with enhancinLy and restorine streams and wetlands in the Caldwell
Station Creek site in Mecklenburg County to serve EEP's program objective and
mitip,ation needs. The project is a mitigation effort and does not impact adjacent streams
and wetlands. See Caldwell Station Creek and associated floodplain wetland restoration
plan for specific information retarding the restoration design.
Page 9 of 13
VIII. Miti ration
DWQ - In accordance with 15A NCAC 2H .0500, mitigation may be required by the NC
Division of Water Quality for projects involving greater than or equal to one acre of impacts to
freshwater wetlands or greater than or equal to 150 linear feet of total impacts to perennial
streams.
USACE - In accordance with the Final Notice of Issuance and Modification of Nationwide
Permits, published in the Federal Register on March 9, 2000, mitigation will be required when
necessary to ensure that adverse effects to the aquatic environment are minimal. Factors
including size and type of proposed impact and function and relative value of the impacted
aquatic resource will be considered in determining acceptability of appropriate and practicable
mitigation as proposed. Examples of mitigation that may be appropriate and practicable include,
but are not limited to: reducing the size of the project; establishing and maintaining wetland
and/or upland vegetated buffers to protect open waters such as streams; and replacing losses of
aquatic resource functions and values by creating, restoring, enhancing, or preserving similar
functions and values, preferable in the same watershed.
If mitigation is required for this project, a copy of the mitigation plan must be attached in order
for USACE or DWQ to consider the application complete for processing. Any application
lacking a required mitigation plan or NCWRP concurrence shall be placed on hold as
incomplete. An applicant may also choose to review the current guidelines for stream restoration
in DWQ's Draft Technical Guide for Stream Work in North Carolina, available at
http://112o.enr.state.ne.us/ncwet]ands/strmgide.htm1.
1. Provide a brief description of the proposed mitigation plan. The description should provide
as much information as possible, including, but not limited to: site location (attach directions
and/or map, if offsite), affected stream and river basin, type and amount (acreage/linear feet)
of mitigation proposed (restoration, enhancement, creation, or preservation), a plan view,
preservation mechanism (e.g., deed restrictions, conservation easement, etc.), and a
description of the current site conditions and proposed method of construction. Please attach
a separate sheet if more space is needed.
The restoration plan is attached. The plan indicates the conservation easement
acquired by the state, plan views, cross section view and proposed method of
enhancement and restoration.
2. Mitigation may also be made by payment into the North Carolina Wetlands Restoration
Program (NCWRP) with the NCWRP's written agreement. Check the box indicating that
you would like to pay into the NCWRP. Please note that payment into the NCWRP must be
reviewed and approved before it can be used to satisfy mitigation requirements. Applicants
will be notified early in the review process by the 401/Wetlands Unit if payment into the
NCWRP is available as an option. For additional information regarding the application
process for the NCWRP, check the NCWRP website at littp://li2o.enr.state.nc.tis/wrp/index.litm. If
use of the NCWRP is proposed, please check the appropriate box on page three and provide
the following information:
Page 10 of 13
Amount of stream mitigation requested (linear feet): N/A
Amount of,buffer mitigation requested (square feet): N/A
Amount of Riparian wetland mitigation requested (acres): N/A
Amount of Non-riparian wetland mitigation requested (acres): N/A
Amount of Coastal wetland mitigation requested (acres): N/A
IX. Environmental Documentation (DWQ Only)
Does the project involve an expenditure of public funds or the use of public (federal/state/local)
land?
Yes ® No ?
If yes, does the project require preparation of an environmental document pursuant to the
requirements of the National or North Carolina Environmental Policy Act (NEPA/SEPA)?
Note: If you are not sure whether a NEPA/SEPA document is required, call the SEPA
coordinator at [phone] to review current thresholds for environmental documentation.
Yes ? No
If yes, has the document review been finalized by the State Clearinghouse? If so, please attach a
copy of the NEPA or SEPA final approval letter.
Yes ? No
X. Proposed Impacts on Riparian and Watershed Buffers (DWQ Only)
It is the applicant's (or agent's) responsibility to determine, delineate and map all impacts to
required state and local buffers associated with the project. The applicant must also provide
justification for these impacts in Section VII above. All proposed impacts must be listed herein,
and must be clearly identifiable on the accompanying site plan. All buffers must be shown on a
map, whether or not impacts are proposed to the buffers. Correspondence from the DWQ
Regional Office may be included as appropriate. Photographs may also be included at the
applicant's discretion.
Will the project impact protected riparian buffers identified within 15A NCAC 2B .0233
(Meuse), 15A NCAC 2B .0259 (Tar-Pamlico), 15A NCAC 2B .0250 (Randleman Rules and
Water Supply Buffer Requirements), or other (please identify Catawba Buffer Requirement )?
Yes ? No ® If you answered "yes", provide the following information:
Identify the square feet and acreage of impact to each zone of the riparian buffers. If buffer
mitigation is required calculate the required amount of mitigation by applying the buffer
multipliers.
Page 11 of 13
Zone* Impact
(square feet) Multiplier Required
Mitigation
1 0 3
2 0 1.5
Total 0
Zone 1 extends out 30 feet perpendicular from near bank of channel; Zone 2 extends an
additional 20 feet from the edge of Zone 1.
If buffer mitigation is required, please discuss what type of mitigation is proposed (i.e., Donation
of Property, Conservation Easement, Riparian Buffer Restoration / Enhancement, Preservation or
Payment into the Riparian Buffer Restoration Fund). Please attach all appropriate information as
identified within 15A NCAC 213 .0242 or .0260.
N/A
XI. Stormwater (DWQ Only)
Describe impervious acreage (both existing and proposed) versus total acreage on the site.
Discuss stormwater controls proposed in order to protect surface waters and wetlands
downstream from the property.
N/A
XII. Sewage Disposal (DWQ Only)
Clearly detail the ultimate treatment methods and disposition (non-discharge or discharge) of
wastewater generated from the proposed project, or available capacity of the subject facility.
N/A
XIII. Violations (DWQ Only)
Is this site in violation of DWQ Wetland Rules (15A NCAC 2H.0500) or any Buffer Rules?
Yes E] No
Is this an after-the-fact permit application?
Yes ? No
XIV. Other Circumstances (Optional):
It is the applicant's responsibility to submit the application sufficiently in advance of desired
construction dates to allow processing time for these permits. However, an applicant may
choose to list constraints associated with construction or sequencing that may impose limits on
work schedules (e.g., draw-down schedules for lakes, dates associated with Endangered and
Threatened Species, accessibility problems, or other issues outside of the applicant's control).
Page 12 of 13
N/A

AT. /l, 2DO5"
Applicant/Agent's Signature Date
(Agent's signature is valid only if an authorization letter from the applicant is provided.)
Page 13 of 13
CALDWELL STATION CREEK AND
ASSOCIATED FLOODPLAIN WETLANDS
RESTORATION PLAN
60% RESTORATION PLAN
MECKLENBURG COUNTY
NORTH CAROLINA
July 2005
PREPARED BY:
tal
I" IARTAT
A` r3E;-'WENTAND
RESTORA T IGi J
HDR Engineering, Inc.
of the Carolinas
CALDWELL STATION CREEK AND ASSOCIATED FLOODPLAIN
WETLANDS RESTORATION PLAN
TABLE OF CONTENTS
1.0 INTRODUCTION ..........................................................................................................................1
2.0 GOALS AND OBJECTIVES ........................................................................................................1
3.0 LOCATION INFORMATION .....................................................................................................2
4.0 GENERAL WATERSHED DESCRIPTION ..............................................................................3
4.1 Land Use/Landcover ........................................................................................................... 3
4.2 Soils .................................................................................................................................. .. 3
4.3 Geology ............................................................................................................................. ..7
4.4 Water Quality .................................................................................................................... .. 7
5.0 HISTORIC AND EXISTING CONDITIONS ........................................................................... ..7
5.1 History of the Proposed Restoration Site .......................................................................... ..7
5.2 Hydrology ......................................................................................................................... .. 8
5.2.1 USGS Gaging Data and Recurrence-Discharge Analysis .................................... .. 8
5.2.2 North Carolina Piedmont Regime Analysis ......................................................... .. 9
5.2.3 Manning's Equation based Estimation of Bankfull Discharge ............................ 10
5.3 Plant Communities ............................................................................................................ 11
5.4 Aquatic Habitat ................................................................................................................. 12
5.5 Protected Species .............................................................................................................. 13
5.6 Stream Geometry .............................................................................................................. 13
5.7 Stream Substrate ............................................................................................................... 15
5.8 Constraints ........................................................................................................................ 15
5.8.1 Utilities ................................................................................................................. 15
5.8.2 FEMA Issues ........................................................................................................ 15
5.8.3 Protected Species and Cultural Recourses ........................................................... 16
6.0 STREAM AND WETLAND RESTORATION PLAN ............................................................. 16
6.1 Wetlands Restoration Plan ............................................................................................... 16
6.2 Enhancement and Preservation Zone ................................................................................ 16
6.3 Enhancement/Restoration Zone ........................................................................................ 17
6.4 Restoration/Creation Zone ................................................................................................ 17
6.5 Stream Restoration Plans .................................................................................................. 18
6.6 Stability and Sediment Transport Analysis ....................................................................... 19
6.6.1 Reference Reach and Regime Analysis ............................................................... 20
6.6.2 USDA and USACE Velocity Analysis ................................................................ 20
6.6.3 Newbury and Gabory's Traction Force Criteria and Shield Curve Analysis....... 20
6.6.4 Bed and Bank Stability Structures ....................................................................... 21
6.7 Planting Plan ..................................................................................................................... 22
6.7.1 Legend for Proposed Planting Zones ................................................................... 22
6.7.2 Zone Descriptions ................................................................................................ 22
7.0 STREAM AND WETLAND PERFORMANCE
CRITERIA AND MONITORING PLAN .................................................................................. 22
7.1 Substrate Monitoring ........................................................................................................ 23
7.2 Vegetation ........................................................................................................................ 23
7.3 Monitoring Schedule ........................................................................................................ 23
7.4 Monitoring Methods ......................................................................................................... 23
8.0 STREAM AND WETLAND RESTORATION BENEFITS .................................................... 24
9.0 REFERENCES ............................................................................................................................. 25
Caldwell Station Creek July 2005
60% Restoration Plan
TABLES
Table 1 - Landcover Analysis
Table 2 - Annual Peak Flows on Little Hope Creek, USGS Gage Station 02146470
Table 3 - Regime Calculations
Table 4 - Manning's Equation Based Discharge Calculations
Table 5a - Estimates of Fluvial Morphologic Parameters - Caldwell Station Creek
Table 5b - Estimates of Fluvial Morphologic Parameters - Unnamed Tributary #2
Table 6a - Master Planting List
Table 6b - Proposed Planting List
FIGURES
Figure 1 - Watershed Area Topography
Figure 2 - Aerial Photography
Figure 3 - Caldwell Station Watershed Landcover
Figure 4 - Caldwell Station Watershed Soils
Figure 5 - Caldwell Station Watershed Geology
Figure 6 - Caldwell Station Watershed History
Figure 7 - Caldwell Station Watershed Historical Map
Figure 8 - Little Hope Creek Return Flows
Figure 9 - Little Hope Creek Watershed Landcover
Figure 10 - Caldwell Station - Cross Sections
Figure 11 - Caldwell Station - Longitudinal Profile
Figure 12 - Caldwell Station - Cross Sections
Figure 13 - Caldwell Station - Existing Conditions Planform
Figure 14 - Caldwell Station -Planform of Plant Communities
Figure 15 - Caldwell Station - Design Planform
Figure 15a - Caldwell Station - Design Planform - UT#2
Figure 15b - Caldwell Station - Design Planform - Overview
Figure 15c - Caldwell Station - Design Planform - Instream Structures
Figure 16a - Wetland and Stream Restoration Cross Sections
Figure 16b - Detail Schematic of Channel Restoration Cross Sections
Figure 17 - Restoration Longitudinal Profiles
Figure 18 - USACOE Velocity Analysis
Figure 19 - Shield Curve for Caldwell Station Creek and UT#2
Figure 20a - Grain-size Curve for Caldwell Station Creek Typical Bar Deposit
Figure 20b - Grain-size Curves for Reference Reach Bar Deposit
Figure 20c - Grain-size Curves for Reference Reach Riffle Areas
Figure 21 - Planting Plan
ii
Caldwell Station Creek July 2005
60% Restoration Plan
APPENDICES
Appendix A Vegetative Cover and Approximate Wetland Limits
Appendix B Photo Index of Caldwell Station Creek Conditions
Appendix C 2003 McDowell Creek Watershed Assessment
Appendix D Reference Reach Documentation
Caldwell Station Creek July 2005
6017o Restoration Plan
CALDWELL STATION CREEK AND ASSOCIATED FLOODPLAIN
WETLANDS RESTORATION PLAN
60% Draft Restoration Plan
Mecklenburg County, North Carolina
1.0 INTRODUCTION
HDR Engineering, Inc. of the Carolinas (HDR) and Habitat Assessment and Restoration Program
lie (HARP) have prepared this stream and wetlands restoration plan (Plan) for Caldwell Station Creek,
un-named tributaries to Caldwell Station Creek, and their associated floodplain riparian areas, for the
intended use of the North Carolina Department of Environment and Natural Resources (NCDENR)
• Ecosystem Enhancement Program (EEP).
The project is located in the Town of Huntersville, Mecklenburg County, at Exit 25 on I-77. The
watershed is rapidly becoming developed due to single-family housing and retail/business infrastructure.
The project location was selected due to the ownership of the land (Town of Cornelius), the
undevelopable nature of the land surrounding the stream, and the instability of the restoration reach.
• This report documents the attainable goals and objectives of restoring both stream and wetland
components within the Project Area and presents an implementation strategy. Plans for stream restoration
are based on Rosgen stream restoration principles and reference reach analysis. Wetland restoration
• follows guidance criteria for restoration projects as laid out in the USACOE RGL#02-2 (12/2002). In
• addition, a monitoring plan and schedule ensure the long-term stability and success of this restoration
effort.
2.0 GOALS AND OBJECTIVES
Restoration projects for aquatic resource impacts need to be founded in a watershed approach that
• recognizes the systemic interactions among its hydrologic, biologic, geologic, and anthropogenic settings
that, in turn, determine its "functional" resource attributes, levels of impairment, and practical strategies
for restoration. The watershed restoration goals in this project include both stream and wetland
components within the same riparian corridor and necessitate careful consideration of the interactions of
• stream and bottomland wetland components. The benefits from the proposed stream and wetland
restorations include water quality improvement, habitat enhancement/restoration, stream stability,
increase in land value, and opportunity for education. These benefits are individually discussed below,
• followed by a description of the specific site attributes and the recommendations for restoration activities.
0 Water Quality
ie
0
•
The areas being proposed for stream and riparian wetland restoration are part of the McDowell
Creek WS-IV watershed that drains to Mountain Island Lake, the primary source for potable
water for the City of Charlotte. McDowell Creek is currently 303(d) listed as impaired due to
biological data with unknown cause(s) (NCDENR, 2003); with a C classification upstream of
Statesville Road (SR 21) and WS-IV classification downstream of SR 21. The class C segments
rank low priority, and the WS-IV portions high priority. Historically the waters were listed as
impaired due to sediment pollution; but at this time additional data collection and analysis must
be performed before a definitive cause can be assigned and the waters move to other rankings for
remedial action. The analysis of existing conditions along the reaches proposed for restoration
show unnatural channel geometry (e.g. dimension and profile) that can be a causative factor in
Caldwcll Station Crcek
60% Rcstoration Plan
July 2005
channel instability and sediment erosion, but also result in substantially lower aquatic habitat.
Downstream on McDowell Creek, the USGS has been monitoring sediment loads for many years
and during large storm flows, such as the May 22, 2003, event, records excessive sediments loads
up to 3,000 tons/day. The primary water quality improvement goal of this restoration effort will
be to restore stream morphologies promoting stability and thus potentially improve downstream
water quality and biological conditions. Secondly, a restoration plan is proposed to protect,
enhance, and restore wetlands to the bottomland areas adjacent to the streams. These wetlands
will promote water quality goals by three means: a) they enhance groundwater storage that
augments baseflow and interstorm stream water quality; b) they intercept and treat overland
stormflow from the adjacent developed residential and commercial properties; and c) they receive
overbank stormflow from the existing stream channels, which provides additional treatment of
stormwater (for discharges exceeding the channel capacity).
Aquatic and Wetland Habitat
The proposed restoration plan will potentially restore and enhance up to 11 acres of bottomland
hardwood wetland, and approximately 3,980 linear feet of 1St to 3"' order streams. The combined
stream and wetland restoration will provide an integrated multifunctional stream corridor that
supports a robust matrix of natural habitats. Structures used to provide for long-term stability in
the restored reach will also enhance the aquatic habitat by reducing homogeneity and providing
for an abundance of niche habitats.
Strewn Stability
Approximately 3,560 linear feet of previously channelized streams will be restored to a natural
state promoting long-term channel stability, which may be a primary factor in biological
impairment of the downstream reaches of McDowell Creek. An additional 420 linear feet of
stream will be enhanced to improve channel stability, water quality and habitat. Increased stream
stability will reduce excess sediment loads and extend the life of the downstream Mountain Island
Lake reservoir.
Land Values
The restoration of stream and wetland functions along the streams within the McDowell Creek
watershed represents intangible community benefits which promote quality of life indices that in
turn underpin and improve land values of the surrounding communities.
Education [Cornelius Eco-park]
The landowner (Town of Cornelius) has proposed to develop an environmental education facility
at this restoration location, preliminarily called an Eco-park. The details on this endeavor are still
being developed and will be discussed in the future as the process becomes more defined.
3.0 LOCATION INFORMATION
The restoration tracts are located to the east of SR 21 approximately 2,000 feet north of the intersection of
SR 21 and Sam Furr Road in northern Mecklenburg County, North Carolina, south of the township of
Cornelius. The Mecklenburg County Tax parcel IDs are 00504219A & B, and 00503219A & B, with 9
and 12 acres, respectively. All tracts are owned by the Township of Cornelius, which has the intent of
using the tracts for an Eco-park. Most of the area lies within the 100-year floodplain for Caldwell Station
Creek. The site can be reached by taking Exit 25 off of I-77 and heading east on Sam Furr Road for
2
Caldwell Station Creek July 2005
60% Restoration Plan
approximately 1,000 feet to the intersection with SR 21, then north for approximately 2,000 feet on
SR 21, where SR 21 crosses the culvert for Caldwell Station Creek.
4.0 GENERAL WATERSHED DESCRIPTION
Caldwell Station Creek and its tributaries lie within the McDowell Creek basin in Catawba River
Subbasin 03-08-33/USGS CU 03050101. The site receives drainage from the upper 2.4 square miles of
headwaters for Caldwell Station Creek. The eastern boundary of the watershed lies along Old Statesville
Road (SR 115), and separates the Upper Catawba River and Yadkin-Pee Dee basins. The location and
topographic settings for these headwaters are detailed in Figure 1. This watershed is located within the
North Carolina Piedmont physiographic province. The province is characterized by rolling hills of
moderate to low relief and is underlain by deeply weathered rocks of variable igneous, metamorphic, and
indurated sedimentary rock types. Drainage is relatively mature with a well-developed dendritic network
of predominantly C and E Rosgen Class streams. The upper watershed to Caldwell Station Creek has
approximately 100 feet of fall from the hilltop divide, along Old Statesville Road (at an elevation of 800
feet above MSL) down to 700 feet above MSL just below SR 21 (a horizontal distance of approximately
1.5 miles). The landcover, soils, and geology of the watershed are described below and illustrated in
Figures 2, 3, 4, and 5.
0 4.1 Land Use/Landcover
A review of the available historical aerial photography dating back to 1938 indicates that the lands
adjacent to, and upstream from, the restoration tracts, along SR 21, have been predominantly rural in
• nature. However, during the last two decades there has been a dramatic increase in both residential and
commercial development. The construction of Interstate 77 (1-77) to the west, and the nearby intersections
of Sam Furr Road with SR 21 and I-77 provide the foundation for a regional commercial/industrial/
• municipal hub around which has developed a large number of residential communities. Color aerial
• photography (2002) of the three watersheds (Figure 2) was digitally classified into landcover types in
order to understand the hydrologic and stream morphologic impacts of land use and landcover changes.
The results from the landcover analysis are shown in Figure 3 and tabulated in Table 1. It is estimated
• that approximately 70 percent of the watershed east of SR 21 is covered by vegetation, with about 42
percent under tree canopy, 24 percent by grass or pasture, and 3 percent by brush. Thirty percent of the
watershed is estimated to be surfaced by either building roofing materials or pavement. The transition
• from a rural landscape, with an approximately equal mix of forested and open agricultural lands, to
suburban lands is still ongoing and will continue to change the runoff characteristics within the watershed
for many years to come. As demonstrated in this report, estimates of the bankfull discharge are greater
than those expected for rural streams with similar watershed areas, yet significantly lower than that seen
in watersheds that are fully developed. Understanding the future hydrologic characteristics of the
watershed depends on what stormwater and land-use controls are instituted to meet existing and future
stormwater management concerns.
4.2 Soils
Soil information for the watershed comes from the Mecklenburg County (County) Soil Survey (USDA,
1980). Figure 4 shows the soils within the contributing drainage basin to the study site. The majority of
the lands in upland areas in this study area are underlain by Cecil CeB2 soils, which then transition
through hill slope and lowland Cecil CeD2 and Helena HeB soils with subordinate Pacolet PaE, Vance
VaB and VaD, Mecklenburg MeB and MeD, Wilkes WkB and WkD, Enon EnB and EnD soils to the
bottomland floodplains exclusively covered by Monacan MO soils. The descriptions of soil types in the
watershed are summarized below (as described in the Soil Survey of Mecklenburg County (USDA, 1980).
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None of the soils in the contributing drainage basin is among the soils on the North Carolina list of Hydric
Soils. (Source: USDA NRCS Soils.)
Cecil Series: Consist of well drained, moderately penneable soils found on broad ridges
and side slopes with grades ranging from 2 to 15 percent. Hydrologic Group B.
CeB2: Cecil sandy clay loam, 2 to 8 percent slopes, eroded.
This well drained soil is on broad smooth ridges on the uplands. Typically, the surface
layer is yellowish red sandy clay loam about 6 inches thick. 77ze subsoil is 47 inches thick.
The upper part is red clay, and the lower part is red clay loant. The underlying material to
a depth of 65 inches is red and yellow loam. The organic matter content is low in the
surface layer. Permeability is moderate, the available water capacity is mediurtn, the
shrink-swell potential is moderate, and surface runoff is medium. Depth to bedrock is more
than 60 inches. The water table is below 6 feet.
CeD2: Cecil sandy clay loan, 8 to 15 percent slopes, eroded.
77tis well drained soil is on side slopes on the uplands. Typically, the surface layer is
yellowish red sandy clay loans about 6 inches thick. The subsoil is 47 inches thick. The
upper part is red clay, and the lower part is red clay loans. The underlying material to a
depth of 65 inches is red and yellow loans. The organic matter content is low in the surface
layer. Permeability is moderate, the available water capacity is medium, the shrink-swell
potential is moderate, and surface runoff is ntediunt. Depth to bedrock is more than 60
inches. The water table is below 6 feet.
Enon Series: Consists of well drained, slowly permeable soils found on broad and narrow
ridges and side slopes with grades ranging 2 to 15 percent. Hydrologic Group C.
EnB: Enon sandy loant, 2 to 8 percent slopes.
This well drained soil is on broad ridges on the uplands. Typically, the surface layer is
brown sandy loans about 7 inches thick. The subsoil is 29 inches thick. The tipper part is
yellowish brown sandy clay loam, the middle part is yellowish brown clay, and the lower
part is yellowish brown clay loam. The underlying material to a depth of 60 inches is light
olive brown clay loam and sandy loam. The organic matter content is low in the surface
layer. Permeability is slow, the available water capacity is medium, the shrink-swell
potential is high, and surface runoff is ntediunt. Depth to bedrock is below 60 incites. The
water table is below 6 feet.
EnD: Enon sandy loam, 8 to 15 percent slopes.
This well drained soil is on side slopes on the uplands. Typically, the surface layer is brown
sandy loam about 7 inches thick. The subsoil is 29 inches thick. The upper part is
• yellowish brown sandy clay loam, the middle part is yellowish brown clay, and the lower
part is yellowish brown clay loam. The underlying material to a depth of 60 inches is light
olive brown clay loans and sandy loant. The organic matter content is low in the surface
layer. Penneability is slow, the available water capacity is medium, the shrink-swell
potential is high, and surface nnoff is rapid. Depth to bedrock is below 60 inches. The
water table is below 6 feet.
s
•
Helena Series: Consists of moderately well drained, slowly permeable soils found on
broad ridges and foot slopes on the uplands. Slopes range front 2 to 8 percent. Hydrologic
Group C.
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0 HeB: Helena sandy loam, 2 to 8 percent slopes.
This moderately well drained soil is on broad ridges and in slightly concave areas around
O the heads of internnittent streams. Typically, the surface layer is light olive brown sandy
loam about 8 inches thick. The subsoil is 32 inches thick. The upper part is brownish
yellow sandy clay loan:, the middle part is brownish yellow and yellowish brown clay, and
• the lower part is mottled yellowish brown, light gray, and reddish brown clay loam. The
• underlying material to a depth of 50 inches is light gray sandy clay. Below, this is light
gray sandy clay loam. The organic matter content is low in the surface layer. Permeability
is slow, the available water capacity is low, the shrink-swell potential is high, and surface
• runoff is medium. Depth to rippable bedrock is 40 to 60 inches. Seasonally, the perched
water table is only I to 2.5 feet below the surface.
e Mecklenburg Series: Consists of well drained, slowly permeable soils found on broad
• ridges and side slopes with grades ranging 2 to 15 percent. Hydrologic Group C.
MeB: Mecklenburg fine sandy loam, 2 to 8 percent slopes.
• This well drained soil is on broad ridges on the uplands. Typically, the surface layer is
dark reddish brown fine sandy loam about 7 inches thick. The subsoil is yellowish red clay
27 inches thick. The underlying material to a depth of 45 inches is mottled strong brown
. and yellowish red clay loam. Below this to a depth of 65 inches it is very dark grayish
brown and light olive brown loam. The organic matter content is low in the surface layer.
Penneability is slow, the available water capacity is medium, the shrink-swell potential is
moderate, and surface runoff is medium. Depth to bedrock ranges from 48 to 60 incites.
• The water table is below 6 feet.
MeD: Mecklenburg fine sandy loans, 8 to 15 percent slopes.
• This well drained soil is on side slopes on the uplands. Typically, the surface layer is dark
• reddish brown fine sandy loans about 7 inches thick. The subsoil is yellowish red clay 27
inches thick. The underlying material to a depth of 45 inches is mottled strong brown and
e yellowish red clay loam. Below this to a depth of 65 inches it is very dark grayish brown
• and light olive brown loam. The organic matter content is low in the surface layer.
Permeability is slow, the available water capacity is medium, the shrink-swell potential is
moderate, and surface runoff is rapid. Depth to bedrock ranges from 48 to 60 inches. The
• water table is below 6 feet.
•
Monacan Series: Consists of somewhat poorly drained, moderately permeable soils found
on floodplains adjacent to streams. Hydrologic Group C.
MO: Monacan soils.
These somewhat poorly drained, nearly level soils are on floodplains along streams and
drainageways. The surface layer of these soils is brownish loan, fine sandy loans, or sandy
loans. The subsoil is reddish loans in the upper part and brownish or grayish silty clay
loam, fine sandy loans, sandy clay loans, and sandy clay in the lower part. The organic
matter content is low in the surface layer. Penneability is moderate, the available water
capacity is high, the shrink-swell potential is low, and surface runoff is slow. Depth to
bedrock is more than 60 incites. Depth to the seasonal high water table is only 0.5 to 2 feet
in winter and early spring. Flooding is for brief periods late in winter and early in spring.
Pacolet Series: Consists of well-drained, moderately permeable soils with slopes ranging
from 15 to 45 percent. Hydrologic Group B.
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PaE. Pacolet sandy loans, 15 to 25 percent slopes.
This well drained soil is on side slopes adjacent to drainageways. Typically, the surface
layer is very dark grayish brown sandy loam about 3 inches thick. The subsoil is 28 inches
thick. The upper part is red clay, and the lower part is red clay loran. The underlying
material to a depth of 65 inches is mottled red, yellowish red, yellow, and reddish yellow
sandy loan. The organic matter content is low in the surface layer. Penneability is
moderate, the available water capacity is low, the shrink-swell potential is low, and surface
runoff is rapid. Bedrock is below 60 inches. The water table is below 6 feet.
Vance Series: Consists of well drained, slowly penneable soils found on broad ridges and
side slopes with grades ranging 2 to 15 percent. Hydrologic Group C.
VaB: Vance sandy loam, 2 to 8 percent slopes.
• This well drained soil is on broad ridges and side slopes on the uplands. Typically, the
surface layer is yellowish brown sandy loam about 8 inches thick. The subsoil is strong
brown clay 25 inches thick. The underlying material to a depth of 50 inches is mottled
• strong brown, yellow, and red clay loam and loann. The organic matter content is low in the
surface layer. Penneabiliry is slow, the available water capacity is medium, the shrink-
swell potential is moderate, and surface runoff is medium. Depth to bedrock range is
• below 60 inches. The water table is below 6 feet.
VaD: Vance sandy loam, 8 to 15 percent slopes.
This well drained soil is on side slopes on the uplands. Typically, the surface layer is
yellowish brown sandy loam about 8 inches thick. The subsoil is strong brown clay 25
inches thick. The underlying material to a depth of 50 incites is mottled strong brown,
yellow, and red clay loam and loam. The organic matter content is low in the surface layer.
Permeability is slow, the available water capacity is medium, the shrink-swell potential is
moderate, and surface runoff is rapid. Depth to bedrock range is below 60 inches. The
water table is below 6 feet.
Wilkes Series: Consists of well drained, moderately slowly permeable soils found on ridges
and narrow side slopes with grades ranging from 4 to 45 percent. Hydrologic Group C.
WO: Wilkes loan, 4 to 8 percent slopes.
This well drained soil is on upland ridges. Typically, the surface layer is dark grayish
brown loam about 4 inches thick. The subsurface layer is brown loam 3 inches thick. The
subsoil is 8 inches thick. The upper part is strong brown clay, and the lower part is strong
brown clay loam. The underlying material to a depth of 48 inches is olive brown, green,
and black sandy loam. Below this is dark colored hard rock. The organic matter content is
low in the surface layer. Permeability is moderately slow, the available water capacity is
very low, the shrink-swell potential is moderate, and surface runoff is medium. Depth to
hard bedrock ranges from 40 to 80 inches. The water table is below 6 feet.
WkD: Wilkes loam, 8 to 15 percent slopes.
• This well drained soil is on narrow ridges and side slopes of the uplands. Typically, the
surface layer is dark grayish brown loan about 4 inches thick. The subsurface layer is
brown loam 3 inches thick. The subsoil is 8 inches thick. The upper part is strong brown
• clay, and the lower part is strong brown clay loam. The underlying material to a depth of
48 inches is olive brown, green, and black sandy loam. Below this is dark colored hard
rock. The organic matter content is low in the surface layer. Permeability is moderately
• slow, the available water capacity is very low, the shrink-swell potential is moderate, and
0
j • 6
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II,?
surface runoff is rapid. Depth to hard bedrock ranges from 40 to 80 inches. The water
table is below 6 feet.
Urban Land (Ur): Consists of areas where more than 85 percent of the surface area is
covered with asphalt, concrete, buildings, or other impervious cover. Most of the soil
material has been cut, filled, and graded, and the natural characteristics altered or
destroyed. The rest is small lawns or shrub gardens near buildings, sidewalks, and in
parking lots.
4.3 Geology
The site lies within the Charlotte belt of the North Carolina Piedmont, which is a geologic province
dominated by large areas of variably metamorphosed plutonic and volcanic rocks. The dominant plutonic
rocks are generally characterized as being pre-, syn-, or post-tectonic with respect to the early and middle
Paleozoic phases of deformation that imparted new textures and secondary minerals into existing units.
The resulting oriented fabrics or foliations represent weaknesses within these rocks that have been worked
on by the forces of weathering and erosion, and are often followed by today's surface streams imparting
to them a lower than expected sinuosity for the low grades and giving them mixed C and E stream class
traits. The Caldwell Creek watershed drains two map units within the Charlotte belt, the mgdf and ntgd
units (Goldsmith et al., 1988). Of these two, the mqd unit is predominant with only a small southern
fringe of the watershed underlain by the mgdf unit. Mild is a unit of grey metamorphosed quartz diorite
and tonalite that is largely composed of the minerals: plagioclase, quartz, biotite, hornblende, and epidote.
The mgdf unit is a metamorphosed finer grained biotite tonalite that is more strongly foliated with the
conspicuous absence of hornblende. The latter yields more clayey soil horizons due to the lower
abundance of quartz. Stream channel density is markedly higher with greater hillslope incision in the
latter of the two units. No exposures of these units appear within the restoration site, and it is presumed
that the reaches in consideration are resting on a thin veneer of aggradational floodplain deposits,
themselves resting on weathered biotite tonalite (saprolite).
4.4 Water Quality
Caldwell Station Creek and its tributaries lie within the approximate 26-square mile McDowell basin,
which has a North Carolina WS-IV classification within the upper Catawba River basin of North Carolina
south of SR 21 to the Mountain Island Lake reservoir, and a C classification from source to SR 21. The
Mountain Island Lake reservoir supplies drinking water to the City of Charlotte. McDowell Creek is
currently CWA 303(d) listed as impaired for biological data of unknown cause(s). The USGS has
instrumented McDowell Creek for water quality investigations, and has reported elevated sediment loads
during storms. A maximum sediment load of 3,000 tons/day (USGS) was recorded on May 22, 2003.
Additional water quality information for the McDowell Creek watershed can be found in the preliminary
engineering watershed assessment report for McDowell Creek watershed completed in 2003 by
Watershed Concepts, Inc; which is presented in Appendix C.
5.0 HISTORIC AND EXISTING CONDITIONS
5.1 History of the Proposed Restoration Site
The historical changes that have occurred along the reaches of interest for this restoration effort within the
. upper Caldwell Station Creek watershed have been investigated by an analysis of aerial photography
dating back to 1938. The series of seven time increments of aerial photographs (1938, 1951, 1956, 1968,
1975, 1980, and 1983) are shown in Figures 6 and 7 for the restoration site. These photographs track the
• evolution of the channels and riparian land uses since 1938.
s
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•
The earliest photography indicates that the two primary streams, Caldwell Station Creek and the
un-named tributary that drains the northern portion of the watershed (Tributary #1 of Figure 1), were
channelized along the upper and lower edges of the Caldwell Station watershed floodplain, and had their
intervening floodplain cleared for agricultural uses. The floodplain in between the two channels had at
least one distributary bifurcation from Caldwell Station Creek which transferred waters into the other
tributary. The interstream distributary branch was located approximately along the current alignment of
SR 21. The channel pattern and riparian land use did not change significantly till the early 1950s, when
Statesville Road was constructed. The first available images after the construction of SR 21 were taken in
1956. The 1956 photography shows the truncation of the lower approximately 3,000 linear feet of
Tributary #1 and the diversion of the stream flow along the eastern embankment of SR 21 to a new
confluence with Caldwell Station Creek just east of the SR 21 culvert. This diversion then resulted in the
approximate doubling of stream flow within the reach of Caldwell Station Creek between SR 21 and the
older, original, confluence (some 3,000 linear feet to the southwest; see middle diagram of Figure 7).
The next significant alteration of the channels in this portion of the watershed came with the construction
of I-77. This occurred between 1968 and 1975 based on the aerial photography. The 1975 aerial
photography shows that the construction of I-77 truncated the remaining elements of the previously
impacted Tributary #1 by diverting the stream along the eastern embankment of I-77 to a new confluence
with Caldwell Station Creek just east of the I-77 culvert. This then further increased the stream flow in
Caldwell Station Creek down to the older, now abandoned, confluence with Tributary #1.
Lastly, in looking at the 1983 aerial photography, Tributary #1 has lines of bare dirt lining both banks
indicating that this reach was redredged in the period leading up to the acquisition of the aerial
p photography.
In summary, the reaches of concern were channelized prior to the earliest available photography and
• likely realigned along opposing fringes of the floodplain to allow better agricultural use of the
• bottomlands. The channels were not totally isolated from each other in these earlier times, as at least one
channel is mapped between Caldwell Station Creek and Tributary #1. The construction of SR 21 resulted
in the abandonment of approximately 3,000 linear feet of the Tributary #1 south of SR 21 downstream to
its earlier confluence with Caldwell Station Creek, and the overloading of Caldwell Station Creek for an
equivalent 3,000 linear feet. As both watersheds have similar drainage areas, this resulted in an
O approximate doubling of flow in this reach. Finally, the construction of I-77 further truncated the lower
• remaining portion of the Tributary #1 from its original confluence up to the east side of 1-77. The flow
was again redirected into Caldwell Station Creek along the eastern edge of I-77, further overloading the
Caldwell Station Creek. It should be noted that Caldwell Station Creek has a culvert under SR 21 that is
insufficient in capacity to convey the 100-year flood (see Appendix Q.
5.2 Hydrology
5.2.1 USGS Gaging Data and Recurrence-Discharge Analysis
The USGS gage station 02146470 on Little Hope Creek [within Hydrologic Unit 030501031 at Seneca
Place in Charlotte [Latitude 35°09'52", Longitude 80°51'11" NAD83] provides the most appropriate set of
flow information with a sufficient period of record to determine both an estimate of bankfull discharge
and a recurrence interval. The drainage area for this station is 2.63 square miles, which is very close to
the 2.39 square miles of combined drainage from the two principal watersheds that converge on the
project site at the confluence just above the SR 21 culvert (see Figure 13). The two watersheds that
converge at the restoration site have similar drainage areas, land use, as well as other physical attributes
(e.g., geology, soils, topography), thus would have comparable rainfall-runoff relationships. This
similarity allows an estimate of their independent contributions to the combined flow to be approximated
Caldwell Station Creek July 2005
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by proportioning the combined flow by their relative drainage basin areas. The gaging station at Seneca
Place has collected peak stream flow data since 1967, and daily stream flow since 1982. The annual peak
data is shown in Table 2. A convention for analyzing the frequency or return interval for floods of a
given magnitude for streams of mid-latitudes has been adopted, which uses a historical set of annual peak
flow data. This method has been referred to as the Weibull method (Dalrymple, 1967; Chow, 1964), and
requires that peak discharges for the period of record be ranked from highest to lowest discharge, and
assigned a probability of "exceedance," P which is calculated by:
P = [m / (n + 1)] x 100 percent, where:
n = number of years of record, and
m = rank or magnitude (1 for the largest, etc.)
The recurrence interval, T, can then be expressed as:
T=(n+1)/m
The discharge and return interval plot for this station is shown in Figure 8. From this plot, estimates of
the discharge for the 1- and 1.5-year storms can be obtained. These return intervals are thought to be
close to the dominant or "channel-forming" storm within the North Carolina Piedmont (Harmon et. al.,
1999, Doll, et. al., 2000). These estimates are 539 cubic feet per second (cfs) for thel-year return storm,
and 727 cfs for the 1.5-year return storm. In order to make an estimate of the independent contributions
arising from the two sub-watersheds converging at the project site, these values are proportioned on a
watershed area basis and yield 307 cfs (1-year return) and 414 cfs (1.5-year return) for Caldwell Station
Creek, and 232 cfs (1-year return) and 313 cfs (1.5-year return) for Tributary #1. The landcover analysis
results for Little Hope Creek are presented in Figure 9 and values are listed in Table 1. The results
indicate that this watershed, which is built-out to full extent, has approximately 50 percent non-vegetated
surfaces, which is significantly higher than the 30 percent estimated for the upper Caldwell Station Creek
watersheds. Thus, the discharge values calculated by this method are considered to be valid projections
for the future flow conditions, should the Caldwell Station Creek watershed be built out in a similar
manner.
5.2.2 North Carolina Piedmont Regime Analysis
A second method of determining the likely dominant (channel forming) discharges in a given setting of
the North Carolina Piedmont is to use "regime" relationships worked out by analysis of streams that have
good bankfull morphologic indicators as well as USGS gaging. This analysis has been performed for
both rural and urban streams in the North Carolina Piedmont (Harmon et. al., 1999, Doll, et. al., 2000)
and generated the following sets of relationships:
Urban Streams (this set is in meters and km2): Rural Streams (this set is in feet and mi2):
Abkf = 3.11 A,r 0-64 Abkf = 66.57 A, 0.s9
Qbkf = 5.44 A,,, 0.57 Qbkf = 18.31 A,r 0.71
S Wbkf = 5.79 A,, 0.32 Wbkf = 11.89 Aw 0.41
Dbkf = 0.54 AW 0.32 Dbkf= 1.50 AW 0.32
In these equations,
A,r = the drainage basin contributing area
Abkf = cross section area of flow at the bankfull stage
• Caldwell Station Creek
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July 2005

Qbkf = discharge at the bankfull stage
Wbkf = width of the water surface at the bankfull stage
• Dbkf = mean depth of flow at the bankfull stage
In a followup study to the urban stream analysis of Harmon et. al., 1999, Forsythe et al., 2004 reanalyzed
the urban bankfull relationships to watershed area for stream located in the Charlotte metropolitan area.
• This latter study recorded stage and discharges directly at sections with bankfull indicators rather than by
extrapolation from USGS gaging station cross sections. It also verified scaling laws within individual
• urban watersheds. The second study verifies the earlier conclusion that urban watersheds have adjusted
• (enlarged) geometries in the Piedmont of North Carolina, but indicates the earlier study over extimated
the adjustments. The modified set of urban relationships (in feet and mil) is
• Abkf = 45.57 AH, 0.64
• Qbkf = 169.55 A, 0"0
W0.29
bkf = 21.53 Aw
•
• Dbkf = 2.11 A,r 035
•
• The stream drainage areas pertaining to this project are shown in Table 3. Both the rural and urban
estimates for Abkf, Qbkf+ Wbkf+ and Dbkf generated from the above equations are listed in this table. It should
be noted that a preponderance of the data used to generate the urban curves was obtained from urban
• streams in Mecklenburg County. The values for bankfull discharges under rural and urban conditions are
dramatically different, begging an implied history of instability as the creeks transition from rural to urban
conditions within their watersheds. The ratios of urban (using the Mecklenburg Co. data, Forsythe et al.,
• 2004) to rural values for discharge and bankfull area, respectively, range from 2 to 3.2 and 2.4 to 3.0 for
the watersheds listed in Table 3. The differences in channel dimensions that are required to carry the
increased stormflow resulting from urbanization of the watershed create challenges in restoration efforts.
• Stability under current conditions and stability under future conditions potentially dictate different
• channel pattern and dimensional attributes. Measures are adopted in the restoration design to limit
instability as the watershed undergoes future development.
5.2.3 Manning's Equation based Estimation of Bankfull Discharge
The observations of bankfull indicators within the three reaches of the restoration site have been
e annotated on the plots of the survey cross sections shown in Figures 10 and 12. The estimated cross-
sectional areas, wetted perimeters, and channel slope, combined with estimated Manning's roughness
coefficients, provide input parameters for discharge calculation at each cross section using the Manning's
S equation. The input parameters and calculated results are presented in Table 4. The estimate of
• Manning's roughness coefficient is subjective and brings some ambiguity into these calculations.
• A roughness coefficient value of .026 is adopted for the tributaries based on the depth of bankfull flow
with respect to diameter of channel bed materials, the stable bed framework, and bed material sizes
following concepts summarized in Arcement and Schneider, 1984. This base value is then modified for
e other resistance factors such as sinuosity, bank vegetation, and obstructions. To reflect reasonable
variation of these parameters within the studied stream reaches, two values of roughness coefficient (.03
and .04) were used to calculate a range of discharge values. The resulting range of discharges for each
• stream is shown in Table 4 wherein values determined using the urban and rural regime relationships are
also shown for comparison. Estimated flows for the Caldwell Station Creek reach upstream SR 21 are
114 cfs (n=.04) or 152 cfs (n=.03), and are higher than estimates generated from the rural regime curves,
• but still lower than that for the urban watersheds of similar drainage area. Flows for Tributaries #1 and #2
n
L
10
Caldwell Station Creek July 2005
• 60% Restoration Plan
•

0 were calculated using Manning's equation and are significantly lower than the rural regime estimates.
This is most likely due to the fact that these streams are E (low gradient-floodplain) reaches that have
• been altered, both by human agrarian practices, as well as more recently by beaver activity. E class
channels, however, can have stable morphologic attributes with bankfull return intervals much shorter
than other stream classes due to the abrupt decay of bed shear stresses at or above the bankfull stage.
• Providing the restoration designs keep bankfull stage at the level of the adjacent flood plain or floodplain
• bench (in the case of the restoration design for UT#2) higher frequencies of bankfull events should not, in
and of itself, lead to instability in the channel.
5.3 Plant Communities
The restoration site has been largely under agricultural land use since the turn of the century. However,
as the historical aerial photographs illustrate, the distribution of open fields has shifted from time to time
. within the floodplain and adjacent hillslope areas, and since the 1980s has shifted to scrub/shrub, pine and
a variety of immature tree species. A detailed map that breaks down the riparian areas within the
restoration tract into ten vegetation communities is shown in Figure 14 and in Appendix A, Figure Al.
• These are briefly described below, and are illustrated by photos located in Appendix A. Figure Al also
illustrates the locations and direction in which the photos were taken.
S Area 1 is Mixed Hardwoods Upland with an average diameter breast height (dbh) of
10". The canopy contains Sweetgum (Liquidambar styraciflua) to 14" dbh, Green ash
(Fraxinus pennsylvanica) to 14" dbh, American elm (Ubnus americana) to 18" dbh,
Persimmon (Diospyros virginiana) to 12" dbh, Red maple (Ater rubrum) to 18" dbh,
• Sycamore (Platanus occidentalis) to 14" dbh, White oak (Quercus albs) to 14" dbh,
Southern red oak (Q. falcata) to 30" dbh, Swamp red oak (Q. shumardii) to 40" dbh,
and Hackberry (Celtis laevigata) to 12" dbh. The subcanopy and shrub layers are
. poorly developed, but do contain Cane (Anmdinaria gigantea) and Autumn Olive
(Elaeagnus untbellata). The largest trees are situated in the western corner of this area.
See Figure A2.
• Area 2 is Pine and Mixed Hardwoods Upland with an average dbh of 8". The
canopy is dominated by Loblolly pine (Pines taeda) to 12" dbh, with Sweet gum to 8"
dbli, Sycamore to 10" dbh, and Red maple to 10" dbh. The subcanopy contains Red
cedar (Juniperus virginiana) to 8" dbh, Tag alder (Abuts serrulata) and Pawpaw
(Asimina triloba). The shrub layer is open and contains Cane and Autumn Olive.
Vines are Catbrier (Smilax spp.). See Figure A3.
Area 3 is mixed Bottomland Hardwoods with Pine Floodplain and has an average
dbh of 8". The canopy is fairly open and contains Sweet gum to 16" dbh, Yellow
poplar (Liriodendron tulipifera) to 10" dbh, Black walnut (Juglands nigra) to 10" dbh,
• Wild cherry (Primus serotina) to 8" dbh, and Loblolly pine to 16" dbh. The
• subcanopy contains Red cedar. The shrub layer is open to dense with Privet (Ligustnan
sinense), Cane, and Tag alder. See Figure A4.
• Area 4 is a relatively young Loblolly Pine Planting Floodplain with an average dbh
of 6". The stand is Loblolly pine to 8" with a subcanopy of young hardwoods. See
e Figure A5.
Area 5 is a relatively young, even aged, mixed Bottomland Hardwoods Floodplain
with potential wetland inclusions, with an average dbh of 6". The canopy is
dominated by Sweet gum to 14" dbh, and Yellow poplar to 10" dbh, with Sycamore to
• 11
Caldwell Station Crcck July 2005
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•

8" dbh, Willow oak (Q. phellos) to 6" dbh, Red maple to 12" dbh, American elm to 8"
dbh, and Black willow (Salix nigra) to 12" dbh. A few Loblolly pines to 12" dbh are
scattered within the canopy. The subcanopy and shrub layers are absent. Standing
water and a de-watering ditch are also in this area. See Figure A6.
Area 6 in an old Former Beaver pond with potential wetland inclusions, which was
• drained a year or more ago. It is dominated by grasses and sedges with a fringe of
small caliper trees and shrubs around the perimeter. These are dominated by Black
willow with Silky dogwood (Comes araonuan), Arrow wood (Viburnum dentatunl),
• Tag alder, Red maple, Green ash, and Elderberry (Santbucus canadensis). See Figure
A7.
• Area 7 is Mixed Bottomland Hardwoods Floodplain with wetlands, with an average
• dbh of 8". It is dominated by Red maple to 10" dbh, with Black willow and Green ash
also present in the canopy. The shrub layer consists of Tag alder, Arrow wood and
Silky dogwood. See Figure A8.
Area 8 is Mixed Bottomland Hardwoods Floodplain with potential wetland
inclusions, a swale-like area below the Beaver dam. It is comprised of even aged small
caliper trees with an average dbh of 4". The canopy contains Black willow to 1011,
• Green ash to 4" dbh, Red maple to 3" dbh, Sycamore to 4" dbh, and a few scattered
Loblolly pines to 10" dbh. The shrub layer contains Tag alder and Button bush
(Cephalanthus occidentalis). See Figure A9.
Area 9 is Mixed Bottomland Hardwoods Floodplain, has a fairly open canopy
dominated by Green ash with an average dbh of 8". The canopy contains Green ash to
• 8" dbh, Sycamore to 12" dbh, Red maple to 24" dbh, and Yellow poplar to 10" dbh.
• The subcanopy consists of Red maple to 8" dbli. The shrub layer contains Black berry
(Rubes spp.), Cane and Arrow wood. See Figure A10.
Area 10 is Mixed Bottomland Hardwoods Floodplain with potential wetland
inclusions, similar to Area 8. It is comprised of even aged small caliper trees with an
average dbh of 4". The canopy contains Black willow to 6", Green ash to 4" dbh, Red
maple to 3" dbh, and Sycamore to 4" dbh. The shrub layer contains Tag alder and
Silky dogwood. See Figure Al 1.
The sewer line that parallels Caldwell Station Creek is overgrown with small caliper
trees, Black berry, and Japanese honeysuckle (Lonicera japonica).
The power line right-of-way is overgrown with a number of small caliper weedy
• species such as Sweet gum and Black locust (Robinia pseudo-acacia).
The undisturbed creek bank is lined with trees that range in size from small shrubs to
30" dbh, with an average dbh of 12 to 14".
5.4 Aquatic Habitat
• Within the three individual stream reaches at the restoration site, riffle and pool habitats are very poor.
• This is due to a combination of factors, the most significant being the lack of appropriate pattern (e.g.,
sinuosity of the channels). The channel beds are dominated by sand and finer materials with no
indications of bedrock. Current beaver activity was observed in these streams, and represents an
• Caldticll Station Crcck
• 60`io Restoration Plan
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12
July 2005
unpredictable factor influencing aquatic habitat. Beaver dams located just downstream of the SR 21
culvert and upstream of the I-77 culvert have created large sections of upstream pooling water. An older,
now breached, beaver dam was developed on Tributary #1, approximately 800 feet upstream from the
confluence with Caldwell Station Creek sometime after the 1983 aerial photography was taken. This had
allowed substantial upstream channel areas to fill in with sediment. The aggradational areas above the
old beaver dam are now mapped as wetlands. Given both, the historical and current indications of beaver
activity, it is reasonable to expect this activity to continue, regardless of the restoration. Surveys of the
existing creek profiles have been made to define existing grade and bed conditions. The longitudinal
profiles of the streams are shown in Figure 11. The locations of debris- and riprap-controlled abrupt
drops in grade are shown on these profiles. The drops in grade form the only riffle areas in the stream,
and from this data a riffle-to-pool ratio of .05 to .2 was found among the three reaches with riffle spaces
ranging from 52 to 185 feet. This indicates very poor conditions in comparison to the reference reach
(see Table 5) but is typical of channelized and dredged steams that are situated in aggradational floodplain
settings. Since the stream was channelized, it is difficult to obtain a true or accurate Rosgen
Classification. The closest approximation that can be derived yields a stream classification of C2 with
virtually no sinuosity.
5.5 Protected Species
A review of the North Carolina Natural Heritage Program database (October 2003) of rare species and
unique habitats for the Cornelius and Lake Norman South USGS quads shows no element occurrence
records for protected species within one mile (1.6 km) of the Project Area. In addition, field
investigations of the terrestrial and aquatic habitats on-site yielded no indication of protected species
listed for the two quads. The table below indicates the listed species, communities and habitats for the
project location.
Scientific Name Common Name State
Status Federal
Status Quad
Status
Condylura cristata Star-nosed mole SC - Historic
Etheostonia collis Carolina darter SC FSC Current
Villosa vau haniana Carolina creekshell E FSC Current
Aster s;eor ianus Georgia aster T C Historic
Helianthus schiveinitzii Schweinitz's sunflower E E Current
Loots helleri Carolina birdfoot trefoil SR-T FSC Current
Thenno psis niollis Appalachian olden banner SR-P - Historic
Gly teniys nuddenber ii Bo turtle T T(S/A) Potential
Cy )rinella zanenia Santee chub SR - Obscure
Sil hium er ollatinn Northern cu plant SR-P - Current
Basic Mesic Forest - - Current
Basic Oak - Hickory Forest - - Current
Wading Bird Rookery - - Current
SC = Special Concern, SR = Significantly Rare, C = Candidate, FSC = Federal Species of Concern,
T = Threatened, E = Endangered
5.6 Stream Geometry
The pattern, dimensions, and profile characteristics of three jurisdictional perennial stream reaches on the
tracts available for restoration above SR 21 were surveyed and the survey results are shown in Figures 10,
11, 12, and 13. The morphologic parameters of three streams are listed in Tables 5a and 5b.
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0
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•
0
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1!
•
•
•
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Pattern
All three reaches lie in bottomland settings within floodplain deposits (i.e., Monacan Series soils).
Within the restoration parcels there are approximately 2,100 linear feet of Caldwell Station Creek
(from the culvert up to the eastern boundary of the property). There are approximately 1,600
linear feet along Tributary #1 between the confluence with Caldwell Station Creek and the
northern property boundary, and approximately 500 linear feet along Tributary #2. The lengths
that were surveyed to verify the map pattern of these reaches are depicted on Figure 13, and were
2,100 feet for Caldwell Station Creek, 1,500 feet for Tributary #1, and 460 feet for Tributary #2.
Caldwell Station Creek, with the exception of one bend located approximately 900 feet upstream
from the SR 21 culvert, is a straight channel that had been realigned to the southern perimeter of
the floodplain prior to the earliest available aerial photography in 1938. The one bend makes the
stream length slightly longer than the valley length, yielding a sinuosity of 1.14. Tributary #1 has
a sinuosity of 1.1, again resulting largely from the artificial diversion of the tributary along the
embankment of SR 21 to join Caldwell Station Creek upstream of the SR 21 culvert. The 1983
aerial photography shows bare dirt dredge spoils lining both banks and indicates that the channel
was recently dredged. Like Caldwell Station Creek, it was straightened along the perimeter of the
floodplain prior to the 1938 aerial photography. Tributary #2 has a sinuosity of I.I. This
tributary has not been clearly identified in the historic aerial photographs, but is believed to be
straightened, given its morphologic attributes.
Dimensions
Cross sections were surveyed for all three tributaries to determine the existing cross section areas
for flow and to provide information to estimate existing bankfull parameters and bankfull
discharges using the Manning's Equation (discussed in Section 5.2.3). The cross sections are
shown in Figures 10 and 12, along with summaries of the dimensional parameters of bankfull
width, cross section area, mean and maximum bankfull depth, and the width/depth (W/D) ratios.
In all cases, the flood prone stage (2 x the maximum bankfull depth) was well above the existing
elevation of the floodplain, such that entrenchment ratios, while in all cases greater than 5, could
not be determined from the cross section information. The estimates of bankfull stage were
determined by bank erosional features developed in the upper bank profiles, but were found to be
inconsistent from one cross section to the next. This could be due to channel obstructions, or
other factors, that have locally influenced bank erosion or channel hydrology. The average
bankfull cross-sectional area for Caldwell Station Creek is 29.9 square feet, is slightly higher than
predicted from the rural Piedmont regime equations. Also, the area is only 50 percent of the area
seen in the reference reach (discussed further), and only 40 percent of the area predicted using the
urban regime curves. The changes seen from one cross section to the next along this reach,
despite its straight alignment, argue that reach is out-of-regime, with some segments undergoing
bank failure, bed aggradation, and commensurate increases in W/D ratios (cross sections #4 and
#6). Other cross sections remained largely unchanged (cross sections #1, #2, #3, and #5). Two
cross sections surveyed for Tributary #1 (cross sections #7 and #8), presented in Figure 12, show
dramatically different cross-sectional areas, and both are smaller than required bankfull-event
area of rural Piedmont streams with similar watershed size. The dimensions here have been
impacted by at least two periods of channelization and dredging, as well as the aforementioned
beaver activity. One cross section was surveyed for Tributary #2 (cross section #9). This cross
section shows bankfull values similar in proportion to the rural curves as Caldwell Station Creek,
with values slightly higher than those for rural conditions, but less than half that seen for urban
settings.
Caltlµell Station Crcck
609o Restoration Plan
14
July 2005

0
Longitudinal Profile
Longitudinal profiles were surveyed along all three reaches and are shown in Figure 11. In each
profile the riffle areas are broken out so that a riffle/pool ratio, average riffle spacing, and grades
can be accurately determined for each bed zone. All three reaches are characterized by short or
abrupt changes in grade, and in almost all cases these were produced by debris blocking the low
flow channel bottom. Despite the floodplain setting, the grades in Caldwell Station Creek
upstream of SR 21 culvert and Tributary #1 are almost twice the grades seen in the reference
reach (discussed below) or in the Caldwell Station reach below the SR 21 culvert. The average
water surface slope for Tributary #1 is artificially too steep due to the channel diversion that was
made when SR 21 was constructed. The profile shows an abrupt steepening of the grade as the
channel enters the diversion zone along the base of the road embankment. The grade for
Caldwell Station Creek is steeper than expected due to the low sinuosity of the creek. Tributary
#2 has the steepest grade of the three streams (.012), and is likely also impacted by
channelization. Tributary #2 is a lower order stream than the other two, and thus a slightly higher
grade would be expected.
5.7 Stream Substrate
The channel beds of all three reaches were surveyed for riffle and pool areas, as well as bedrock. The
riffle areas exist due to either riprap infill (laid in Caldwell Station Creek upper sewer line crossing near
the SR 21 culvert) or woody debris deposition. No bedrock has been encountered in any of the surveyed
reaches. All reaches are characterized by sandy material with very limited zones of fine gravel and
pebbles. Samples of bed materials for grain size analysis were collected from typical lateral and medial
bars within the channelized reach of Caldwell Station Creek above SR21. The results are shown in Figure
20a, and indicate a low range in grain sizes with a mean of .08 mm (coarse sand).
5.8 Constraints
5.8.1 Utilities
The stream restoration design has several sources of constraints that are outside the realm of fluvial
morphology and hydrology. First, two existing wastewater mains run in parallel direction with Caldwell
Station Creek and Tributary #1 and are in close proximity. The mains cross these streams in several
places in the project area. Second, the high probability of increase in impervious area due to watershed
build-out, leading to increased peak flow runoff rates, is a real concern.
5.8.2 FEMA Issues
The preliminary engineering report prepared for Mecklenburg County by Watershed Concepts in 2003
(see Appendix C) indicates that under current conditions the SR 21 culvert does not pass the 100-year
flood, and will result in overtopping SR 21. No structures in this part of the watershed lie within the
100-year floodplain.
The FEMA Flood Insurance Rate Map (FIRM) panel number 0046 for Mecklenburg County and
incorporated areas, which includes the project area, was updated in February 2004. Since the majority of
the project area lies within the FEMA detailed study limits, the proposed wetland and stream restoration
project will be located inside the Caldwell Station Creek floodway boundary. Therefore, due to possible
changes in 100-year WSE, the hydraulic analysis of this development is required.
15
Caldwell Station Crcck July 2005
60% Restoration Plan
s
M
a
•
The available HEC-RAS model (Model) of this FEMA study shows four model cross sections upstream
of SR 21 culvert and their WSE during the 100-year storm event. The terrain changes resulting from the
project will need to be reflected in the Model and a "No-Impact" on the 100-year WSE must be
documented and certified.
The modeling process requires the following steps:
• Development of the correction to the existing model by updating the existing FEMA Model with
recent surveyed terrain topographic data.
• Adding more modeling cross sections in the area of proposed changes into the corrected existing
model - creating an effective existing model.
• Implementing the proposed changes into the cross sections - creating an effective proposed
model.
• Comparing the effective existing and effective proposed model for any changes.
5.8.3 Protected Species and Cultural Recourses
Protected species and cultural resources will not be impacted by the proposed restoration plan and
therefore they do not present any design constraints.
6.0 STREAM AND WETLAND RESTORATION PLAN
6.1 Wetlands Restoration Plan
There are four general approaches to wetland restoration: creation, restoration, enhancement, and
protection. The bottomland settings of the restoration tracts are natural environments for bottomland
hardwood wetlands.
Of the 21 acres of available land in the restoration parcels, there are approximately 7.3 acres of wetlands
that are likely to meet jurisdictional wetland criteria based on existing hydrology, plant communities, and
soils (see Figure A12 in Appendix A). These existing areas are considered threatened due to precarious
hydrologic conditions and are likely candidates for enhancement and preservation. There are 1.2 acres of
transitional wetlands, wherein one can find mixed wetland and non-wetland plant and soil conditions.
The upper 12 inches of soil in the transitional zone are currently saturated, but this may not persist
significantly into the growing season. The area of mixed conditions would likely be available for either
restoration or enhancement, depending on verification of the current jurisdictional status. Lastly, there
are approximately 2.5 to 3 acres of riparian bottomlands, where wetlands may be restorable if stream
restoration can be performed in a manner that enhances wetland hydrology. The three classes of potential
wetland restoration are shown on Figure 15, and conceptual design plans for all three classes of
restoration are discussed below.
6.2 Enhancement and Preservation Zone
Water level recorders have been installed to monitor soil hydrology in the upper 18 inches over the next
few months. Soils in this zone are largely Monacan Series floodplain silts and sands with an upper hydric
soil horizon. Hydric conditions are not as uniform as wetland hydrology and vegetation would indicate,
and believed to be due to the unstable, aggradational nature of the floodplain. Newly laid floodplain
deposits are oxidized sediments derived from upland soils, and will only become reduced as organic
matter accumulates and decays over time within a seasonally saturated soil environment. Thus, in some
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Caldwell Station Creek July 2005
60% Restoration Plan
zones, such as the old beaver pond area, some borings have yielded hydric soils, while others show upper
oxidized layers overlying reduced organic-rich horizons.
In order to enhance the existing wetlands area, the following four strategies are proposed. First, existing
overland drainage shall be intercepted upslope of wetland areas and redirected into wetland areas by
appropriate grading without the use of hard structures. Second, existing drainage ditches within the
bottomlands (old field drainage ditches) should be blocked and existing wetland areas strategically
bermed along downslope fringes to restrict overland outflow. Third, to the feasible extent, stream
restoration will be performed in a manner that allows seasonal/spring overflow of the storms approaching
the bankfull discharge recurrence. The implied shorter bankfull recurrence interval is justified for E class
Rosgen channels. Finally, planting will occur to enhance wetland ecology that will increase organic soil
contents; a necessary precursor to hydric soil development.
6.3 Enhancement/Restoration Zone
The 1 to 2 acres of land with some indications of wetland conditions are to be enhanced or restored to
M bottomland wetlands by the same mix of strategies described in Section 6.2. In this area, where existing
• vegetation is not of significant value, an additional strategy will initiate a more aggressive program of
regrading within the floodplain to promote wetland hydrology. The existing topography is currently
being mapped at the 6-inch contour level to facilitate detail planning for restoration in this zone. Once the
mapping is completed, the data can be combined with the vegetation data to determine which soil areas
could be regraded to promote wetland hydrology and hydric soil development. Depending on the soil
characteristics, some soil amendments may also be exploited. Otherwise, the same strategies as described
• in Section 6.2 for the area enhancement and preservation shall be used.
6.4 Restoration/Creation Zone
e
• There are an additional 3 acres of land distributed along the central corridor and southern fringe of the
property that represent opportunities for additional wetland restoration. There are basically three
environments, which could be transformed into bottomland hardwood wetlands. Two of these
environments constitute restoration and one creation.
0 The first restoration area lies along the southern edge of the enhancement/restoration zone, and represents
the potential expansion of this wetland area if the strategies used to enhance the transitional wetland areas
are successful. The expanded areas abut the proposed realigned and restored Caldwell Station Creek,
which would have a margin of elevated relief to retain overbank flow within the floodplain fringe in the
periods following overbank flow storm events. Surface drainage would be terminated from all wetland
areas, such that interflow or groundwater flow would be the only output, other than evapotranspiration.
Where feasible, low permeability soils will be used for surface regrading in wetland areas, as the
maintenance of perched water table conditions will be essential to meet hydrologic wetland criteria in
proximity to the restored Tributary #1 or Caldwell Station Creek.
The second restoration wetland area is located along the southernmost edge of the property, where it may
be feasible to restore hillslope wetlands when the existing Caldwell Station Creek is moved over to the
central corridor of the restoration tract. The proposed new alignment for Tributary #2 will use the old
Caldwell Station Creek alignment, but will have a higher elevation through the zone with E-class channel
dimensions that promote seasonal overbank flows and increase the local water table in this zone. As the
zone lies along the north facing toe of the hillslope, low solar radiation and enhanced seasonal overbank
flows have a reasonable chance of creating the hillslope wetlands in this area.
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Caldwell Station Creek July 2005
60% Restoration Plan
The one area of wetland creation lies in a proposed linear hollow that would be left along the abandoned
channel alignment of Caldwell Station Creek. The natural reference model for wetlands of this nature is
an abandoned "ox-bow." As meander bends grow and eventually cut off on E-type channels in floodplain
settings, they fill and eventually create bottomland hardwood wetlands. The bottom of the abandoned
channel will lie near, or above, the regional water table. In the case of the proposed abandoned alignment
for Caldwell Station Creek, it should be possible to infill and broaden the old channel bottom to create a
broader hollow of bottomland hardwood wetlands. A detailed grading plan for this area will be created
after the detailed topographic maps of the site are available.
6.5 Stream Restoration Plans
All three perennial stream channels on the property were previously modified and have altered pattern,
dimensions, and profile characteristics. In order to develop an appropriate design framework for these
• channels, it was essential to find and document a stable, natural, E-type Rosgen channel for a watershed
of similar size, land use, physiographic, and geologic setting. Over 20 potential reference reaches located
nearby were investigated over the course of two months, and finally a stable E-reach was found located
north of the project site in the Mooresville, NC, area along the lower portions of West Fork Reeds Creek.
• The documentation of the reference reach is enclosed in Appendix D, and the reference reach
morphologic parameters are summarized in Tables 5a and 5b along with the parameters for existing
S conditions of the degraded reaches. The reference reach data is directly applicable to design parameters
• for Caldwell Station Creek and Tributary #1 under current watershed land use conditions. Additional
reference reach data collected from smaller tributaries in the Charlotte area are shown in Table 5b for the
restoration design for Tributary #2. The reference reach information in conjunction with NC Piedmont
• regime data and site constraints are all used in combination to formulate the best possible design
constraints to achieve habitat, water quality, and channel stability goals. As such, the restoration
parameters listed in Tables 5a and 5b represent a balanced consideration of all governing factors.
The preliminary restoration design established new alignments for 1,861 linear feet of Caldwell Station
Creek, 160 linear feet of Tributary #1, and 1,539 linear feet of Tributary #2 (Figure 15).. Approximately
420 additional linear feet of Tributary #2 is proposed for enhancement (Figure 15a). This brings the
potential total stream restoration and enhancement to 3,980 linear feet. All three of the reaches proposed
for restoration involve adding new significant elements to the pattern, dimension, and profile. The
proposed alignments shown in Figure 15 have been selected to be appropriate to current land use and
hydrologic attributes, as well as to protect and enhance riparian wetlands. Meander belt widths, radii of
curvature, and sinuosities are all based on consideration of reference reach conditions as well as site-
specific constraints.
The stream restoration plan is shown in more detail in Figures 15b and 15c. Figure 15b shows the
proposed new alignments overlain on the more detailed topography of the site that was collected in order
to formulate the hydrologic improvements for wetland habitat. The plan shows how the new alignments
in combination with strategically placed bank and floodplain low head (< 1 ft) levees and small berms
will augment both the frequency of flooding and duration of saturation with the various components of
the wetland areas. Bank side levees mimic those found in natural E-type channels of the North Carolina
Piedmont, and are thus consistent with a design-to-nature approach. A number of smaller old drainage
gullies will be blocked.
Figure 15c shows the locations of the instream bank stability and habitat features. The design uses bio-
engineering approach that integrates habitat and stability measures on a feature-by-feature basis. The
• instream structures are discussed further in the next section. The riffle zones shown in the inflection areas
of the stream are diagrammatic in their length on this plan. The average riffle length and spacing are
• shown in Tables 5a and 5b.
•
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Caldwell Station Creek July 2005
• 6017a Restoration Plan
The restoration of dimensional attributes for the restoration reaches is illustrated in Figures 16a and 16b.
Figure 16a shows cross sections from which one can determine the inter-relationship of the channel
restoration measures to the surrounding floodplain. Figure 16b illustrates the consistency of the proposed
restoration channel dimensions to the specific design dimensional parameters of Tables 5a and 5b. The
detail cross sections located at Figure 16b also illustrate the designed stabilization measures and the
proposed vegetated zones. The planting design detail is presented in the Section 6.7.
The restoration longitudinal profiles for UT#2 and Caldwell Station Creek are shown in Figure 17. The
length of the riffle zones, their spacing, and riffle/pool ratios are based on the reference reach conditions.
Riffle and pool slopes have been adjusted to match overall E-type channel valley slope constraints. The
• slope of the riffle zones has been checked for continuity with transportable dominant (D50) grain sizes,
and therefore, over time with bankfull events, should not aggrade under nominal environmental
conditions. The emplacement of meander bends within the restored reaches will result in the excavation
• of 4- to 18-inch pools along the reaches within each pool area. These pools are not shown on Figure 17 as
they will naturally develop hydraulically in a short period (generally 1 to 3 years) after the restoration is
completed. The armoring of the inflection zone riffle areas with rounded natural river cobble with a D84
sized for immobility will promote and enhance long term riffle habitat. Thus the restoration will produce
a dramatic improvement in aquatic habitat in the reach with both the restored pool and riffle areas. Over
90 percent of the existing stream channels consist of sand runs with very low habitat.
6.6 Stability and Sediment Transport Analysis
There are four approaches to the analysis of stability for this restoration project. First is the reference
• reach foundation for the design's pattern, dimension, and profile. This paradigm assumes that nature finds
a stable design for any given watershed setting, provided there is sufficient time for adaptation and
evolution. This design model assumes that nature will find comparable fluvial morphologies for
• comparable sets of watershed characteristics (topography, climate, soils, bedrock, land use, etc.). Thus,
one check on the stability of a design is that it has similar characteristics to those observed in the selected
reference reach areas.
A corollary to this reference reach model is the regime approach. The regime approach states that at a
. regional level, there are some central tendencies in streams of similar morphologic class (e.g. Rosgen
E- or C-type streams) to have comparable morphologic parameters for similar drainage areas. The regime
approach has the benefit of averaging out a lot of "noise" that occurs in individual watersheds, such as
• disruption of normal tendency by odd events or features (e.g. hurricane, downed tree, small pond, etc.).
• Neither the reference reach nor the regime approach is necessarily sufficient to achieve a stable design.
Both sets of data are susceptible to yielding guidelines that may be erroneous for a given circumstance.
Thus, independent of the reference reach or regime data, a separate effort must be made to check or verify
the stability of the restoration design.
The second and third methods used here for stability analysis are the determinations of transport
• thresholds for bank and in-stream materials. These checks on transport, or erosion potential, for bed and
• bank materials are either a minimum velocity analysis or critical traction force analysis. There are two
approaches for checking velocity thresholds for the design at Caldwell Station and two approaches for the
critical traction force analysis.
Finally, stability can be examined from a structural viewpoint. Structures can be emplaced or found (e.g.
the stream can be located over or within bedrock) to provide added stability. These structural approaches
• are usually folded into a given project as a design unfolds and areas of greater risk, or opportunity, are
• discovered.
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Caldwell Station Creek July 2005
. 60`70 Restoration Plan
6.6.1 Reference Reach and Regime Analysis
Tables 5a and 5b show reference reach information gathered from various sources. None of the reference
reaches are sufficiently comparable in stream or watershed attributes to use a direct design template and
assurance for stability. The restoration morphologic parameters need to reflect the anticipated future
changes in the contributing catchment, as well as the wetland restoration goals within the adjacent
floodplain. Increasing overbank flooding to improve wetland hydrology means increasing the frequency
of the bankfull event. This is accomplished in two different approaches for UT#2 and Caldwell Station.
UT#2, which is fed by in part by large commercial parcels with requirements for storm water BMP's,
needed to have slight dimensional adjustments in the restoration plan, as there is less expectations for
increased storm flow with mitigating BMP's in place. For the larger Caldwell Station Creek, however,
the build out landuse will be primarily residential with no anticipated requirements for storm water
BMP's. For this restoration, dimensions slightly over the rural dimensions, but significantly under the
dimensions for urban conditions have been selected to meet project goals.
The regime equations developed for the rural and urban Piedmont were shown in section 5.2.2. The
e regime values for the restoration reaches are shown in Table 3. As previously discussed, the reference
reach data are reasonably consistent with the regime curves, and therefore, provide a reasonable basis for
the extrapolation and selection of restoration parameters.
The restoration design attached in planform, section, and longitudinal views of Figures 15, 15a, 15b, 16a,
16b, and 17 can be characterized by the morphologic parameters indicated in Tables 5a and 5b. Meander
bend radii of curvature, wavelength, meander belt width, riffle/pool ratios, sinuosity, bankfull widths,
depths and cross section areas have all been selected to be consistent with the range of conditions seen in
the reference reach data, and the North Carolina regime data. While the primary concern is the impact of
future urbanization on the restoration morphology, this concern is largely mitigated by the construction of
E channels with aggressive grade control. All morphologic elements have been selected to be
hydraulically in equilibrium with a morphologically-defined bankfull flow event. As E channels have
abrupt attenuations of bed traction forces and mean velocities with flood stages over tile bankfull
elevation, the frequency of bankfull events cannot be considered a determinant morphologic attribute of
the reach. For these reasons, a fixed bankfull discharge design approach is not required to assure stability.
6.6.2 USDA and USACE Velocity Analysis
The USACE (1994) published a graph of allowable velocity-depth data for granular materials ranging in
size from 0.1 to 500 millimeters (mm). The range of expected bankfull mean velocities is listed in Tables
5a and 5c, and extends from approximately 2.5 to 4.5 feet per second (fps). The expected range in
velocities are plotted in Figure 19 on a stability chart from the USACE (1994) that can be used determine
the range of sizes of granular materials that would be unstable as exposed incoliesive materials along the
channel. This is the shaded area shown in the figure. From this analysis, it is clear those materials with
D50,S less than 1 centimeter (cm) will be unstable with Caldwell Station Creek, and .1 cm for UT#2. For
these reasons all banks areas with fine soils will need to be matted to protect banks until vegetation is
established with good root density and depth.
6.6.3 Newbury and Gabory's (1993) Traction Force Criteria and Shield Curve Analysis
For streams with non-cohesive bed materials greater than 1 cm in diameter (fine gravel), a general rule of
thumb for stability may be approximated as:
Tractive Force (Tau; kg/m^2) = incipient diameter (cm)
20
Caldwell Station Creek July 2005
60?7o Restoration flan
This is an empirical relationship arising from a compilation of in transport streambed materials and
tractive force observations for a wide range of channels worldwide. The Newbury and Gaboury criteria
are derived from compilations presented by Lane (1955) and Magalhaes and Chau, (1983). These critical
traction force versus grain size analyses and curves are sometimes referred to as Shield Curves. Tables 5a
and 5b include calculations of the bed traction force derived using the following equation:
• Tau (kg/m^2) = 1,000 x (depth (m)) x (slope (ft/ft))
This relationship is roughly equivalent to the Tau = RS formulation used by Rosgen (1994) but can yield
more accurate estimations of the maximum traction forces needed for stability analysis, as a maximum
• depth can be used in lieu of the hydraulic radius. For a successful restoration, one is more concerned with
the maximum conditions that may exceed thresholds and trigger failure in the channel system. Thus, the
DS rather than RS method is used here to calculate critical traction forces. The values in the tables are
• estimated for the floodprone stage. The corresponding threshold diameters for particle stability (using the
first equation) are then multiplied by a 1.5 safety factor, and used to determine the D84 for the inflection
zone grade control cobble and cross vane material.
• Figure 18 shows a variation of a "Shield Curve" with data from Leopold (1964). On this figure the
expected conditions for events with floodprone stages (2 x maximum Bankfull depth) are plotted to show
the corresponding stable threshold particle sizes for both Caldwell Station Creek and Uf#2. These values
• are lower than the design diameters for riffle armor and cross vanes and thus indicate the design should be
adequate to stabilize the bed.
• 6.6.4 Bed and Bank Stability Structures
The attached plans, cross-sections, and longitudinal profiles show the location of structures present in the
design to assist in the stabilization of the restored channel.
First, with respect to bed or grade stability, at the upper and lower tie-in points on affected reaches cross
vanes will be installed with rock sized for immobility. Second, cross vanes are to be installed
• approximately every 4`t' inflection zone in conjunction with the cobble material to augment riffle habitat.
• Again cross vane and riffle materials are sized to promote long term bed stability. The estimates for D50
and D8; for riffle armor are noted in Tables 5a and 5b.
• Where the proposed new channels leave the old alignments, channel plugs will be installed up to the
surrounding floodplain elevation for a minimum distance of 20 feet.
Inner meander bends are graded to a lower slope (z4:1; run/rise) to allow attenuation of flood velocities at
or near the bankfull stage. The outer banks of meanders are treated either with a series of 2 to 3 rock
vanes or with the layered footer - coir fiber lop, - brush mattress - soil lift system shown in Figure 16b.
Tile footers buried below the low flow water line with allow meander pool development without bank toe
failure and coir fiber roll subsidence. The brush mattress will leaf out and provide pool shade, bank
resistance to sloughing and rotational failure, and displace the thalweg high velocity line away from the
bank, lowering bank shear stresses. The overlying soil-lift will distribute bank load over the brush
mattress and prevent soil loss and bank sloughing.
Typical installation schematics will be included in the final construction documents for all features.
21
Caldwcll Station Creck July 2005
607o Restoration Plan

6.7 Planting Plan
The vegetation installed as part of the Caldwell Station stream restoration project is an integral
• component that provides stability, habitat enhancement and long-term project viability. As such, the
HDR/HARP team has provided a master list of commercially available species that can be used for the
planting of the proposed wetland restoration and enhancement zones and the new stream corridors.
Initially the Caldwell Station Creek site was segregated into ten zones of vegetation communities, based
on the existing plants, topography, and hydrology. However these 10 components can be grouped into
three existing and one potential zone, for enhancement. Figure 21 shows the regrouping of the ten zones
in four zones, A, B, C and D. The planting plan is therefore based on the four zone arrangement.
A Master List for shrubs and trees (Table 6a) and Zone specific planting lists (Table 6b) have been
• developed as the basis of the plan. Since quantities and types of commercially available material changes
due to environmental conditions, nursery availability and active project requirements, not all of the
species listed will be used in the final planting effort. However, the list is broad enough such that ample
• species and quantities should be available at the time of planting.
6.7.1 Legend for the Proposed Planting Zones
The enclosed planting lists for the proposed planting plan have been developed primarily for enhancement
of the existing flora. As such, the species recommended for the A, B, and C Planting Zones are those
selected from the Master Lists of Trees and Shrubs that do not occur (or are not abundant) on this site.
• Selecting these species provides for a greater diversity in the final product. It is assumed that the existing
flora will provide the propagules for volunteer fill-in of the site.
No attempt has been made to recreate a "typical" natural N.C. Plant Community, as described by Schafale
and Weakley, but rather an enhancement of a diverse habitat in the Piedmont, using species native to this
physiographic province.
• 6.7.2 Zone Descriptions
Zone A - This zone is a relatively dry bottomland hardwood forest. There may be seasonal flooding, but
standing water is not a long-term condition.
Zone B - This zone is a wet bottomland hardwood forest. Seasonal flooding occurs with extended
periods of standing water. Jurisdictional wetlands are a component of this zone.
Zone C - This is the vegetation of the restored streambank. The shrub species selected are those that will
provide maximum bank stability and potential shade for the aquatic habitat.
Zone D - This zone includes easements and potentially disturbed areas that require planting following
construction. Areas in this zone have not been determined as yet. They may fall into Zones A-C, or as a
result of construction, could constitute a new zone.
7.0 STREAM AND WETLAND PERFORMANCE CRITERIA AND MONITORING PLAN
Restoration of Caldwell Station Creek and Tributaries #1 and #2 will be deemed a success after the
monitoring period is complete. The stream channel should maintain its dimension, pattern, and profile
over time. Additionally, instream structures should remain secure and stable during the monitoring
22
Caldwell Station Creek July 2005
60% Restoration Plan
period. The wetlands should maintain a steady vegetative growth of diverse, non-invasive and native
plant species. The plant species should appear healthy. Organic matter is expected to accumulate.
It is also expected that there will be some minimal changes in the cross-sections, profile, and/or substrate
composition. Changes that may occur during the monitoring period will be evaluated to determine if they
represent a movement toward a more unstable condition (e.g., down cutting, deposition, and/or erosion)
or if they are minor changes that represent an increase in stability (e.g., settling, changes in vegetation,
and/or decrease in width-to-depth ratio). Unstable conditions that require remediation will indicate failure
of restoration activities.
7.1 Substrate Monitoring
A Modified Wolman Pebble Count (Rosgen, 1996) provides a quantitative characterization of streambed
• material. This composition information is used as an indicator of changes in stream character, channel
form, hydraulics, erosion rates, and sediment supply. Pebble count data can be used to interpret the
movement of materials in the stream channels. Established D50 and D84 sizes should increase in
• coarseness in riffles and increase in fineness in pools. Data collected over the monitoring period should
be plotted over that of the previous year(s) for comparison. Over time, established D50 and D84 should
be compared.
7.2 Vegetation
Native vegetation, as determined by reference reach vegetation inventories, will be planted. Survival of
vegetation within the riparian buffer will be evaluated using survival plots. Survival of live stakes will be
evaluated along the restoration site. Vegetation survival of target dominant species will be confirmed.
Woody vegetation will be monitored for five years, or for two bankfull events. Plants should be replaced
per the contract documents. Permanent sampling quadrats will be established at random locations within
the restoration site. Expected desired species will be monitored and records of sampling locations will be
maintained. Non-native, exotic, and undesirable species will be noted during the sample collection.
7.3 Monitoring Schedule
Annual monitoring is required for a minimum five-year period beginning in 2006, until success criteria
are met. Reports will be submitted annually to the USACE and the NCDWQ Ecosystem Enhancement
Program.
7.4 Monitoring Methods
Monitoring at established locations will ensure consistency and allow comparison of data over time.
Permanent cross-sections will be established in Caldwell Station Creek and Tributaries #1 and #2. Cross-
section changes can indicate changes in the width-to-depth ratio of the stream. Bank slopes and the flood
plain bench should remain stable. Comparison of longitudinal profiles during the monitoring period will
indicate excessive changes over time. Monitoring at these locations, as well as established vegetation
plots and pebble count locations, will ensure consistency and allow comparison of data over time.
Wetlands will be monitored at sufficient number of established quadrats. The records of a specie density,
growth of cross-sectional area, height, and coverage will be maintained and compared to reference
community. The shifts in the plant community detected from year to year provide a basis for
management decisions. Wetland hydrology will be monitored to demonstrate improvements in the
number of days of saturated soil conditions in the upper 12 inches during the March 15`h to November 15"i
growing season and/or the frequency of overbank flooding. In addition anaerobic wetland soil conditions
23
Caldwell Station Crcck July 2005
60% Restoration Plan
shall be demonstrated by monitoring soil redux values within the wetand restoration areas. These shall be
determined using standard field techniques for saturated soils (i.e. using calibrated platinum-tipped and
reference-bridge soil Eh probes).
8.0 STREAM AND WETLAND RESTORATION BENEFITS
The primary goal of stream restoration is to promote long-term channel stability. Channel stability
implies sediment transport continuity, aquatic habitat stability, and improvement of water quality, for all
of the reasons described in Section 2.0. Most elements affecting channel flow regime can also influence
channel stability. Thus, all aspects of the proposed work must be evaluated using a number of analytical;
means (mostly by comparison to known stable reference streams or published hydraulic relationships).
The secondary goal of stream restoration is to enhance and stabilize aquatic habitat within the low flow
channel. Currently, the channel has a scarcity of both pools and riffles.
The primary goals of wetland restoration are to improve the overall water quality and provide for water
storage, flood conveyance, aquatic habitat, enhanced stability, and aesthetic improvement to the
watershed.
24
Caldwell Station Creek July 2005
G0?7o Restoration Plan
9.0 REFERENCES
Arcement, G.J., Jr., and V.R. Schneider, 1984, Guide for Selecting Manning's Roughness Coefficients for
Natural Channels and Floodplains, FHWA-TS-204 or USGS Water Supply Paper 2339.
Chow, V.T., 1964, Handbook of Applied Hydrology, McGraw-Hill, New York, NY.
Dalrymple, T., 1960. Flood-Frequency Analysis. Manual of Hydrology, 3. Flood-Flow Techniques,
Water Supply Paper 1543-A, USGS, Washington, DC.
Doll, Barbara, D.E. Wise-Frederick, C.M. Buckner, S.D. Wilkerson, W.A. Harmon, R.E. Smith, R.E.
2000. Hydraulic Geometry Relationships for Urban Streams throughout the Piedmont of North
Carolina, in NCSU Course Notes: N.C. Stream Restoration Institute, River Course, Raleigh, NC.
Forsythe, R., et al. Regime and Design Issues for Urban Piedmont Streams, 2004 Stream Restoration
Conference, June 22-23, 2004, Winston-Salem, NC. (http://www.bae.ncsu.edu/programs/extensionlwgg/sri/).
Goldsmith, R., Milton, D. J., and Horton, J. W., Jr., Geologic Map of the Charlotte 1° x 2° Quadrangle,
North Carolina and South Carolina, Misc. Inv. Series, Map I-1251-E, USGS, Washington, DC.
Harmon, et. al., 1999. Bankfull Hydraulic Geometry Relationships for North Carolina Streams. In:
AWRA Wildland Hydrology Proceedings. D.S. Olsen and J. P. Potyondy eds., AWRA Summer
Symposium, Bozeman, Mt, pp. 401408.
NCDENR/DWQ, 2003. North Carolina Water Quality Assessment and Impaired Waters List (2002
Integrated 305(b) and 303(d) Report).
Rosgen, D.L., 1997. A Geomorphological Approach to Restoration of Incised Rivers, Proceedings of the
Conference on Management of Landscapes Disturbed by Channel Incision.
Rosgen, D.L., 1996. Applied River Morphology. Wildland Hydrology Books, Pagosa Springs, CO.
Rosgen, D.L., 1994. A Classification of Natural Rivers, Catena 22 (1994): 169-199.
United States Department of Agriculture, 1980. Soil Survey of Mecklenburg County, North Carolina.
Natural Resource Conservation Service.
USACOE, 2002. Regulatory Guidance Letter, No. 02-2. Guidance on Compensatory Mitigation Projects
for Aquatic Resource Impacts Under the Corps Regulatory Program Pursuit to Section 404 of the
Clean Water Act and Section 10 of the Rivers and Harbors Act of 1899.
r.
• 25
• Caldwell Station Creek July 2005
607o Restoration Plan
•
TABLES
•..........•r••••••••••••••••••••s•••••s•s••
Table 1. Landcover Analysis - Caldwell Station Creek, Unnamed Tributaries #1 and #2, and Little Hope Creek
UT #2 to Caldwell Station
Creek UT #1 to Caldwell Station
Creek Caldwell Station
Creek
West Fork Reeds Creek Little Hope
Creek
Class Samples Percent Samples I Percent Samples Percent Samples Percent Samples Percent
decid_trees 14629 42.2 29914 35.1 30615 34.5 935817 21.5
conif_trees 1820 5.2 4354 5.1 7030 7.9 0 0.0
Subtotal trees 16449 47.4 34268 40.2 37645 42.4 935817 21.5
grassl 1405 4.0 10441 12.2 10517 11.9 343842 7.9
rass2 5219 15.0 15331 18.0 11159 12.6 594072 13.7
Subtotal grass 6624, 19.1 25772, 30.2 21676, 24.4 937914, 21.6
scrub-shrub 1526 4.4 2696 3.2 2912 3.3 0 0.0
Total Pervious 24599 70.9 62736 73.5 62233 70.1 1873731 43.1
Com/ind-bld 1301 3.7 4470 5.2 2854 3.2 328196 7.5
asphalt 2301 6.6 5688 6. 5120 5.8 485470 11.2
as halt2 3310 9.5 6523 7.6 11911 13.4 277678 6.4
shingled_bldg 946 2. 3399 4.0 4788 5.4 470646 10.8
shin led_bld 2 217 0.6 446 0.5 190 0.2 697324 16.0
shin led bld 3 2031 5.9 2076 2.4 1629 1.8 214335 4.9
Total Impervious 10106 29.1 22602 26.5 26492 29.9 2473649 56.9
Total 34705 100.01 1 85338 100.01 1 88725 100.01 1 4347380 100.0
Table 2. Annual Peak Flows (Little Hope Creek)
(USGS Gane St. 021464701
Year Date Stage
(ft) Discharge
(cfs)
1967 8/22/1963 8.12 1110
1968 6/8/1964 7.91 1020
1969 7/23/1965 6.39 487
1971 5/12/1967 7.32 788
1972 7/25/1968 8.39 1240
1983 12/5/1979 7.02 1170
1985 6/6/1981 8.47 1680
1988 8/27/1984 6.36 684
1989 5/8/1985 7.09 988
1990 5/26/1986 6.49 736
1995 8/26/1991 7.77 1280
1996 8/10/1992 6.64 766
1997 7/22/1993 8.50 1700
1998 4/8/1994 7.91 1350
1999 1/22/1995 6.70 791
2000 7/11/1996 5.81 454
2001 6/27/19971 1 5.68 412
2002 5/29/19981 1 6.60 749
BEST FIT discharge (cfs) = 539.15 + 1067.8 x log (Return Interval (year))
Return Interv aI
(year) Discharge
(cfs)
0.5 218
0.75 406
1 539
1.25 643
1.5 727
2 861

Table 3. North Carolina Rural and Urban Piedmont Regime Calculations
Urban (Doll et al., 2000) Rural (Harmon et al., 1999)
Site Drainage
Area k Drainage
Area Aw X-Section
Area Abkf Flow
Qbkf X-Section
Area Abkf Flow
Qbkf Bankfull Width
Wbkf Bankfull Depth
Dbkf Flow
Qbkf X-Section
Area Abk1 Flow
Qbki X-Section
Area Abkf Bankfull Width
Wbkf Depth Dbk1
(sq.miles) (sq.km) (sq--) (cros) (sq.ft.) (cfs) (m) (ft) (m) (ft) (cfs) (sq.tL) (cros) (sq.m.) 00 00
Caldwell St. Creek 1.36 3.52 6.96 11.15 74.94 393.73 8.66 28.42 0.81 2.65 87.52 23.06 2.48 2.14 13.57 1.66
Caldwell St. Creek Trib.1 1.02 2.64 5.79 9.46 62.34 334.19 7.90 25.92 0.74 2.42 67.75 18.58 1.92 1.73 11.99 1.51
UT#2 To Caldwell St. Ck. 0.40 1.04 3.18 5.55 34.24 196.00 5.86 19.21 0.55 1.79 29.45 9.21 0.83 0.86 8.02 1.12
Caldwell St. Creek -below
confluence with Trib.#1 2.39 6.19 9.99 15.38 107.51 542.97 10.38 34.04 0.97 3.17 144.56 35.20 4.09 3.27 17.29 1.98
West Fork Reeds Creek 1.49 3.86 11.75 79.45 414.76 8.92 29.26 0.83 2.73 94.93 24.69 2.69 2.29 14.11 1.70
Little Hope Creek, Seneca
Place 2.49 6.45 H1 15.74 110.36 555.80 10.51 34.49 0.98 3.22 149.93 36.29 4.25 3.37 17.60 2.01
Urban (Mecklenburg County; Forsythe et al., 2004)
Site Drainage
Area k Drainage
Area A„, Flow
Qbkf X-Section
Area Abkf Flow
Qbkf X-Section
Area kkf Bankfull Width
Wbkf Depth Dbkf
(sq.miles) (sq.km) (cfs) (sq.ft.) (cros) (sq.m.) 00 00
Caldwell St. Creek 1.36 3.52 206.43 55.48 5.85 5.15 23.54 2.35
Caldwell St. Creek Trib.1 1.02 2.64 171.71 46.15 4.86 4.29 21.65 2.12
UT#2 To Caldwell St. Ck. 0.40 1.04 94.32 25.35 2.67 2.36 16.51 1.53
Caldwell St. Creek -below 2.39
confluence with Trib.#1 6.19 296.12 79.59 8.39 7.39 27.72 2.86
West Fork Reeds Creek 1.49 3.86 218.85 58.82 6.20 5.46 24.17 2.43
Little Hope Creek, Seneca 2.49
Place 6.45 303.99 81.70 8.61 7.59 28.05 2.90

Table 4. Manning's Equation Based Discharge Calculations at the Morphologic Bankfull Channel Dimensions
Bankfull Dischar e
X-section Mean W/D Hydraulic Wetted Manning's Mannin 's Equation Re ime E nation
Stream Area
s ft Width
ft Depth
ft Ratio
ft/ft Radius
ft Perimeter
ft Coefficient
n1 n2 Slope
ft/ft
A0i (cfs) AAG,
(cfs)
10, (cfs)I
Q, cfs)
Caldwell Station Creek 29.9 13.0 2.3 5.9 1.699 17.6 0.04 0.03 0.0052 114.0 152.1 87.5 206.4
Caldwell Station Creek Restored 52.0 20.0 3.8 5.3 1.884 27.6 0.04 0.03 0.004 186.4 248.5 87.5 206.4
Unnamed Tributary #1 10.4 9.0 1.2 8.1 0.912 11.4 0.04 0.03 0.0058 27.7 36.9 67.8 171.7
Unnamed Tributary #2 13.2 7.3 1.8 4.0 1.211 10.9 0.04 0.03 0.0012 19.3 25.7 29.5 94.3
Unnamed Tributary #2 Restored 9.0 9.0 1.0 9.0 0.818 11.0 0.04 0.03 0.004 18.5 24.7 29.5 94.3
West Fork Reeds Creek 61.9 20.3 3.1 6.7 2.336 26.5 0.04 0.03 0.0017 166.9 222.6 94.9 218.8
A Discharge based on a Manning roughness of .04
AA Discharge based on a Manning roughness of .03
Q, Rural regime discharge estimate
Q„ Urban regime discharge estimate
Table 5a. Estimates of Fluvial Morphologic Parameters - Caldwell Station Creek

Parameters Caldwell Station
Existing Conditions Reeds Creek West Fork
Reference Reach Caldwell Station
Restoration Parameters
Watershed Area (sq. miles) 1.36 1.49 1.36
Bankfull Width (ft) 13 20.3 20
Bankfull Area (sq. feet) 29.9 61.9 50
Ave. Bankfull Depth (feet) 2.3 3.1 3 to 3.8
Max. Depth (feet) 3.2 4.9 4 to 5
Flood Prone Width (feet) >100 >100 >100
Entrenchment Ratio >7.6 >5.1 >5
W idth/Depth Ratio 5.9 6.7 5 - 6.5
Valley Slope (feet/feet) 0.0046 0.0020 0.0052
Average Water Slope (feet/feet) 0.0046 0.0017 0.004
Sinuosity 1 1.2 1.2
Riffle/Pool Ratio 0.077 0.51 0.5
Riffle Slope 0.08 0.0028 0.01
Pool Slope 0.0018 0.0013 0.0012
Ave. Riffle Spacing (feet) 185.4 28.1 63
Riffle Substrate D50 (mm) NA 3.2 3.2
Riffle Substrate D84 (high) (mm) NA 6.8 6.8
Riffle Armour D50 (mm) NA 17.0 200.0
Riffle Armour D84 (high) (mm) NA 28.0 400.0
Bulk Stream Bed D50 (mm) 0.8 4.5 0.8 to 3.2
Bulk Stream Bed D84 (high) (mm) 1.5 7.3 1.5 to 7
Meander Radius of Curvature (ft) 29.6 41.2 41.2
Meander Wave Length (ft) N/A 111.2 111.2
Meander Belt Width (ft) N/A 76.2 76.2
Bankfuli Discharge (cfs) ' 114 to 152, avg.: 133 167 to 223, avg.: 195 186 to 249, avg.: 217
Bankfull Est. Mean Velocity (ft/sec) 4.5 3.15 4.34
Fioodprone (2x Bankfull stage) Bed
Shear Stress (Newtons/sq m) 1541.41 82.61 270.95
Maximum Diameter for Bankfull
Sediment Movement (cm) 157.29 8.43 27.65
Floodprone (2x Bankfull stage) Bed
Tractive Force (lb/sq ft) 33.55 1.80 5.90
Rosgen Class " Channelized Ditch E3 E3
' Estimated using Manning Eq. Assuming Manning Coef..03 min, .04 max, .035 avg.
" Rosgen & Silvey, 1998

Table 5b. Estimates of Fluvial Morphologic Parameters - UT#2
Parameter UT to Mill Ck. Lewisville,
NC, Forsyth Co. UT to Yadkin River
Yadkin Co. Flat Branch, Six Mile Ck.
Mecklenburg Co. UT#2 to Caldwell Station Ck.
Existing Conditions UT#2 o Caldwell Station Ck.
Restored Conditions
Watershed Area (sq. miles) 0.29 0.38 0.30 0.4 0.4
Bankfull Width (ft) 6.7 7.5 10.0 7.3 9
Bankfull Area (sq. feet) 6.6 9.8 9.1 13.2 9
Ave. Bankfull Depth (feet) 1.0 1.3 0.9 1.8 1
Max. Depth (feet) 1.4 1.5 1.8 2.5 1.8
Flood Prone Width (feet) 25.0 9.8 24.5 NA 45
Entrenchment Ratio 3.73 1.31 2.45 NA 5
Width/Depth Ratio 6.7 5.8 11.0 4 9
Valley Slope (feet/feet) 0.012 0.016 0.010 0.013 0.005
Average Water Slope (feet/feet) 0.009 0.014 0.009 0.012 0.004
Sinuosity 1.30 1.11 1.10 1.11 1.27
Riffle/Pool Ratio 0.62 0.65 2.29 0.11 0.6
Riffle Slope 0.018 0.030 0.021 0.17 0.008
Pool Slope 0.003 0.003 0.003 0 0.003
Ave. Riffle Spacing (feet) 15.38 41.00 39.00 52.8 31
Riffle Substrate D50 (mm) NA 1.00 8.50 <1.00 8 to 20
Riffle Armour D50 (mm) NA NA NA NA 66.3
Riffle Armour D84 (mm) NA NA NA NA 132.7
Bulk Stream Bed D50 (mm) NA 0.58 2.80 <1.00 <1.00
Meander Radius of Curvature (ft) 15.2 19.0 25.0 22.4 24
Meander Wave Length (ft) 56 93 44 128.3 90 - 100
Meander Belt Width (ft) 33 50 35 WA 35
Bankfull Discharge (cfs) ' 22.21 47.97 30.18 69.94 21.20
Bankfull Est. Mean Velocity (ft/sec) 3.38 4.92 3.32 5.30 2.36
Bankfull Bed Shear Stress (Newtons/sq m) 155.45 270.95 231.39 2558.98 86.70
Maximum Diameter for Bankfull Sediment
Movement (cm) 15.86 27.65 23.61 261.12 8.85
Bankfull Bed Tractive Force (lb/sq ft) 3.38 5.90 5.04 55.69 1.89
Rosgen Class " E E/C C Eroding C Channel/ May have been
channelized in the past E
Estimated using Manning Eq. Assuming Manning Coef..035
" Rosgen & Silvey, 1993
Table 6a. Master Planting List
Shrubs
Common Name Scientific Name Size Structure Position Exposure Indicator Zone Province
1 Red buckeye Aescu/us Pavia B'-12' Mid Shade -FAC A-D C
2 Piedmont bucked Aescu/us sylvatica 3'10' Toe-Mid Shade _ FAC A-D P
3 Ta alder Alnus serru/ata 16 r Shade/Sun FACW B-C-D M-P-C
4 Devils walkin stick Aralia s inosa 10'-20' Mid Shade FAC A-D M-P-C
5 Chokecher Aronia arbutifolia 8'-10' Toe FACW B-C-D M-P-C
6 Beautyberry Callicarpa americana 6' Toe_ FACU- A-B-C-D P-C_
7 Sweet shrub Cal canthus flondus 81-10' colonial/fibrous Mid Shade FACU+ A-D M-P
8 New Jersey tea Ceanothusamericanus 3' fibrous To UPL M-P-C
9 Button bush Ce ha/anthus occidentalis 6'-10 fibrous Toe OBL B-C-D M-P-C
10 Sweet pepper bush Clethra alnilolia 31-10' coloniaVfibrous _Mid-Top FACW _B-C-D LP-C
-
11 Silk dogwood Cornus amomum 10' coloniallfibrous Toe-Mid FACW+ B-C-D Mm-
P
12 American hazelnut Co /us americanus fibrous FACU A-D M-P
13 Strawberry bush Euon mus americanus 3'-6' fibrous To Shade FAC- B-C-D M-P-C
14
15 Dwarf fothergilla
Smooth hydrangea Fothergilla gardend
Hydrangea arborescens 3'-5'
3'-5 fibrous
fibrous -Top
Top_ Partial shade
Shade _FACW
_FACU B-C-D
A-D C
M-P
16 Carolina holly flex ambi ua var. montana fibrous Mid-To UPL M-P-C
17 1nkber holly flex labia 3'-6' fibrous To FACW B-C-D C
18 Winterberry holly Ilex verticillata 31-10' fibrous Toe-Mid FACW B-C-D M-P-C
19 Virginia willow ltea virginica 3'-5' fibrous All Partial shade FACW+ B-C-D M-P-C
20 Do hobble Leucothoe axillans var. editorum 3'-5 colonialifibrous Toe-Mid Shade FACW B-C-D C
21 Spice bush Lindera benzoin 3'-10' fibrous To Shade FACW A-D M-P-C
22 Male-berry Lyonia ligustrina 10' fibrous _FACW_ B-C-D _M-P-C
23
24 Ninebark
Rhododendron Physocarpus opubfolius
Rhododendrons . 5'-10'
4'-12' fibrous
fibrous Toe-Mid
Toe-Mid
Shade FAC-
FAC A-D-
A-D M-P _
M-P-C
25 Winged sumac Rhus co ailina 5'-12' taproot Mid UPL M-P-C
26 Elderberry Sambucus canadensis 10' colonial/fibrous Toe FACW- A-B-C-D M-P-C
27 Bladdernut Staphy/ea trifolia 10' coloniaVfibrous Toe-Mid_ -Shade _FAC A-D P
28 Coralber S m horica s orbiculatus 2'-4 colonial/fibrous Top Shade FAC- A-C-D M-P
29 Blueberries Vacccinium slop. 3'-10' coloniallfibrous Mid-Top Partial shade FACU A-D M-P-C
30 Arrowood Viburnum dentatum var. lucidum 6'-12' colonial/fibrous Toe-Mid FACW B-C-D P-C
31 Possum haw Viburnumnudum fibrous FACW+ _B-D _LM-P-C
32 Dusty Zenobia Zenobia putveru/enta 3'-5' colonial/fibrous _
Top OBL B-D C
Trees
Common Name Scientific Name Size Indicator Zone
1 Red maple Acerrubrum Canopy FAG A-B-D
2 Serviceber Amelanchierarborea Sub-canopy FACU A-D
3 Pawpaw Asimina triloba Sub-canopy FAC A-D
4 River birch Betu/a nigra Canopy FACW_ A-B-D
_
5 Ironwood Ca inus carohniana Sub-canopy FAC A-D
6 Bitternut hickory Carya cordiformis Canopy FAC A-D
7 Hackber Celtic laevi ata Canopy FACW A-B-D
8 Redbud Cercis canadensis Sub-canopy FACU A-D
9 Fringe tree Chionanthus viiginicus Sub-canopy FACU A-D
10 __
Flowering dogwood Cornus Ilorida _
-
Sub-canopy _
_
FACU A-D
11 Persimmon Dios ros vii iniana Sub-canopy FAC A-B-D
12 Green ash Fraxinus pennsylvanica Canopy FACW A-B-D
13 Silverbell Halesia carohna Sub-canopy_ _FAC- A-D
-
-
14 Witch hazel Hamamelsvir iniana Sub-canopy FACU A-D
15 Deciduous holly flex decidua Sub-canopy FACW A-B-D
16 American holly flex o aca Sub-canopy FAC- A-D
17 Black walnut _ Jug/a- nigra _Canopj _FACU_ A-D
18 Yellow poplar Liriodendron tuli ifera Canopy FACU A-B-D
19 Black um N ssa s Ivatica Canopy FAC A-B-D
20 Sycamore Platanus occidentalis Canopy FACW A-B-D
21 Cottonwood Populus deltoides Canopy __FAC+ A-B-D
22 White oak Ouercus alba Canopy FACU A-D
23 Overcup oak Ouercus l rata Canopy OBL B-D
24 Swam chestnut oak Ouercus michauxii Canopy FACW A-D
25 Water oak Ouercus nigra Canopy _ FAC A-D
26 Cherrybark oak Ouercus pagoda -Canopy _FAC+ A-D
27 Pin oak Ouercus alustris Canopy FACW A-B-D
28 Willow oak Ouercus hellos Canopy FACW- A-B-D
29 Red oak Ouercus rubra -Canopy _FACU_ A-D
30 Shumard oak Ouercusshumardii Canopy FACW A-B-D
31 Black willow Sa6x ni ra -
Canopy OBL B-D
32 Silk willow Salix sencea Sub-canopy OBL B-D
33 American elm Ulmus americana Canopy FACW A-B-D
Table 6b. Proposed Planting List
Zone A
Trees
Common name Scientific name Stratum Indicator Zone Province
River birch Betula ni ra Canopy FACW A-B-D
Bitternut hickory Ca rya cordiformis Canopy FAC A-D
Black um N ssa s /vatica Canopy FAC A-B-D
Cher bark oak Quercus pagoda Canopy FAC+ A-D
Swam chestnut oak Quercus michauxii Canopy FACW A-D
Deciduous holly flex decidua Sub-canopy FACW A-B-D
Ironwood Carpinus caroliniana Sub-canopy FAC A-D
Shrubs

Piedmont buckeye Aesculus s (vatica 3'-10' FAC A-D P
American hazelnut Co lus americanus 3'-10' FACU A-D M-P
Smooth hydrangea Hydrangea arborescens T-5' FACU A-D M-P
Spice bush Lindera benzoin 3'-10' FACW A-D M-P-C
Bladdernut Staphylea trifolia 10' FAC A-D P
Zone B
Trees
Common name Scientific name Stratum Indicator Zone Province
Overcu oak Quercus l rata Canopy OBL B-D
Pin oak Quercus alustris Canopy FACW A-B-D
River birch Betula ni ra Canopy FACW A-B-D
Cottonwood Po ulus deltoides Canopy FAC+ A-B-D
Silky willow Salix sericea Sub-canopy OBL B-D
Shrubs
Chokecherry Aronia arbutifolia 8'-10' FACW B-C-D M-P-C
Beautyberry Callicar a amencana 6' FACU- A-B-C-D P-C
Strawberry bush Euon mus americanus T-6' FAC- B-C-D M-P-C
Winterber holly flex verticillata T-10' FACW B-C-D M-P-C
Virginia willow Itea virginica 3'-5' FACW+ B-C-D M-P-C
Zone C
Shrubs
Common name Scientific name Stratum Indicator Zone Province
Tag alder Alnus serrulata 16' FACW B-C-D M-P-C
Dog hobble Leucothoe axillaris var. editorum 3'-5' FACW B-C-D M-P
Virginia willow Itea vir inica 3'-5' FACW+ B-C-D M-P-C
Sweet pepper bush Clethra alnifolia T-10' FACW B-C-D LP-C
Silky dogwood Cornus amomum 10' FACW+ B-C-D M-P
Elderberry Sambucus canadensis 10' FACW- A-B-C-D M-P-C
Coralber S m horicar os orbiculatus 2'-4' FAC- A-C-D M-P
Male-berry Lyonia ligustrina 10' FACW B-C-D M-P-C
M-Mountians Province
P-Piednont Province
C-Coastal Plain Province
FIGURES

and NCEEP Caldwell St. Creek Figure 1. Watershed Topography
4
, Restoration Site and USGS Hydrology (1:24,000) 1/29/0
'R'M'v All I
`?M`N' Mecklenburg Co., NO
0 .5 1 mile
•••.....•.••••••••••••••••••••••••••••••••••
ty4 s7 F ?d_ i x

M1 t ? Y.r S. ?. •?
X tip; .
4
\ ._

?i
0 .5 1 mile
NCEEP Caldwell St. Creek Figure 2. 2002 Color
and Restoration Site Orthophoto 1/29/04
A=s: A -
Mecklenburg Co., NO Mosaic of Watershed
Landcover Groups
¦ Trees
¦ Grasses
0 Scrub - Shrub
Pavement
Buildings
Caldwell Station
Watershed
NCEEP Caldwell Station Creek Site Figure 3. Landcover in the Caldwell Station
Watersheds - "Supervised" Spectral 4/04
Mecklenburg County, NC
_7 Maximum Likelihood Classification Algorithm
Un-named
Tributary # 2 Watershed
? vets[ -? _L 1
3 v V
Q02
O -
/ e82
HeB
j /
O VaB CeD2
U
v E_np HeB He13 f /..
COB?
r 4i ? yep?.
EnB
q) `
-z' I ?r 9? J Ur
G rP.
? HeB V,i
h y_)
VaB CeB7 ' CeB2 r CeB2
cP?? Mo Qb m Crp2
C
_ eD HeF3 W
CeD2 e
71 17&
CeD2, rc, 0?ll % .
?k6
17/// ;e62 V °ieB
r? -
VaEs
6 CeB2 o PaE '
Ht E3 Ce82
1 cP o t? wke ?`'•? • ?• ??
J rieB Ce172
L CeD2 / MQO PaE Wkf3
Q Val O
WkB COB? ?.
P? CeDz
?O. UH2 CeB2
HeB f
v CeB2 ? -
v •
_ wkU _ _ II _2
EnD CeD2 HeB
ra '` N
n _ r ,n } /`aN k Mp
p .5 1 mile
NCEEP Caldwell St. Creek Figure 4. Soil Types
a? Restoration Site 1 /29/04
H.„ ,.
of the Watershed
Rs,<.•.? ` its Mecidenburg Co., NO
.?....
-- - ?-
t
P
I "\\\
L ?1
• ? r ti.
a 73

?f.
Cor6
•.•
L IL S7 I
?C?1•tt?
J L7 LL- L L t-

? i
n 70
......... -
A
1
L

70
35 --

jr
n te
1
-i" Brad Ctoj,
from Goldsmith, Milton, & Horton, 1988
0 .5 1 mile
NCEEP Caldwell St. Creek Figure 5. Geologic Map
.... Restoration Site 1/29/04
RRic o- . ,, Mecidenburg Co., NC of the Watershed Area
.. I[
1W6
1956
1968
1980

1 Qf:? 1
1966
1975
1983
NCEEP Caldwell St. Creek Restoration Site Figure 6. Historical Conditions
Mecklenburg Co., NC 1938 - 1983 Aerial Photography Jan. 2004
•
• Channelized and displaced to floodplaln edges
i

• / /
/ S1eNei
Site Area
/ /
• / V a / / /
• f Inbrbranch Ch.nnel

• _ SAM FURR ROAD
1938

i•

•
•
•
I•
•

•

•
'•
• 1956
•
• -
•
i /
t • /
• I /

• I /
Site Area
I
•
/
y
•
r
• 1
1 /
,•
•

?• 1975
a"d NCEEP Caldwell St. Creek Restoration Site
Mecklenburg Co., NC
0
1951
Pre-Statesville Road
Pre-Interstate 77

Rodredgad Channal.

I /
1 / Sae Area
v
? /
I
7 I
K
/
I
i
1983
Figure 7. Historical Conditions Jan. 2004
1938 - 1983 Aerial Photography
Little Hope Creek, at Seneca Place
USGS STATION 2146470 1967 - 2002
1800
Discharge(cfs
1600
218
406
539
643
727
860
1400
1200
v
d
L
1000
V
0
800
600
400
0
Y = MO + M1 *log(X)
MO 539.15
M1 1067.8
R 0.96665
5 10 15
Return Interval (years)
20
NCEEP Caldwell Station Creek Site Figure 8. Estimate of Discharge and
Return Interval USGS Gaged Stream of 4/04
?r Mecklenburg County, NC Similar Drainage Area
USG;
Figure y. Lanacover in the uttie Hope L.K.
NCEEP Caldwell Station Creek Site Watershed - "Supervised" Spectral 4/04
: „°` ?t Mecklenburg County, NC Maximum Likelihood Classification Algorithm

720 S Caldwell Station X-Section #1 N
718
716
.
714
712
710
ti
.----..:
708
n 0
50 1W 150
Bankfull Width = 12.7 ft Bankfull Max Depth = 4.5 ft
200 250
Floodprone Width > 260 ft
3W
Bankfull Area = 43.8 sq. ft Bankfull Avg. Depth = 3.4 ft Entrenchment Ratio > 20.4
W/D = 3.7
722 S Caldwell Station X-Section #2 N
720
718
716
714
712
710
o
ft
So 'W 15°

Bankfull Width = 11.2 ft Bankfull Max Depth = 2.7 ft
zoo 250

Floodprone Width > 270 ft

300
Bankfull Area = 22.7 sq. ft Bankfull Avg. Depth = 2.0 ft Entrenchment Ratio > 24.1
W/D = 5.5

S
722
Caldwell Station X-Section #3
N
720
718
716
714
712
710

'
H 0
l 150
50 IW
Bankfull Width = 11.6 ft Bankfull Max Depth = 2.9 ft 2W 2
Floodprone Width > 242 ft 50
Bankfull Area = 23.9 sq. ft Bankfull Avg. Depth = 2.1 ft Entrenchment Ratio > 20.7
W/D = 5.6

S
722
Caldwell Station X-Section #4
N
720
71a
71s
714
712
7 1 0
---••-''?
ft o so ,W ,so
Bankfull Width = 18.1 ft Bankfull Max Depth = 3.4 ft 200 2
Floodprone Width > 250 ft so
Bankfull Area = 40.6 sq. ft Bankfull Avg. Depth = 2.2 ft Entrenchment Ratio > 13.8
W/D = 8.1
722 S Caldwell Station X-Section #5 N
720
718
716
714
712
710
e
So , W , ?
200 250
n Bankfull Width = 9.6 ft Bankfull Max Depth = 2.6 ft Floodprone Width > 230 ft
Bankfull Area = 20.1 sq. ft Bankfull Avg. Depth = 2.1 ft Entrenchment Ratio > 24.0
W/D = 4.6

S Caldwell Station X-Section #6
722
720
7te
N
716 1-
714
712
710
n o so ,W
Bankfull Width = 14.9 ft Bankfull Max Depth = 3.3 ft ,?
Floodprone Width > 130 ft
Bankfull Area = 28.5 sq. ft Bankfull Avg. Depth = 1.9 ft Entrenchment Ratio > 8.7
W/D = 7.8

NCEEP Caldwell St. Creek Figure 10. Cross Sections

2004
J
an
Restoration Site - Mecklenburg Co., NC Existing Conditions Caldwell Station Ck. .
Caldwell Station Creek Above 21 Longitudinal
716
714
712
p 710
Cz
O
W
708
706
704

<«;? v
e' r
4 wm? see
4. I Po<.17c?iw
F-I
III q I' ? bhis D.iin
I3 j
i ?
! P
Iql '
i
I'
p
716 F
714
712
c
O
c- 710
4
W
708
706
704
1500
Caldwell Station Tributary #2 Longitudinal
717
710
715
c
O
.= 714
O 713
W
712
711
710
500 400 300 200 100 0
Distance (ft)
Overall Grade = 0.012

-d
.--w,.....'? NCEEP Caldwell St. Creek
Restoration Site - Mecklenburg Co., NC Figure 11. Longitudinal Profiles,
Caldwell Station Ck. and Assoc. Tributaries Jan. 2004
2000 1500 Distance (ft) 1000 500 v
Overall Grade CS = 0.0040 Overall Grade CS Above 21 = 0.0046 Overall Grade CS Below 21 = 0.0026
Caldwell Station Tributary #1 Longitudinal
INC Distance (ft) 500 0
Overall Grade = 0.0058

720
718
716
714
712
710
708
ft
Caldwell Station X-Section #9 (Tributary #1)
Caldwell Station X-Section #8 (Tributary #1
SJ 1 W 150 2W 2s
Bankfull Width = 8.9 ft Bankfull Max Depth = 2.3 ft Floodprone Width > 230 ft
Bankfull Area = 12.7 sq. ft Bankfull Avg. Depth = 1.4 ft Entrenchment Ratio > 25.8
W/D = 6.2
720 r
719 jl`rLF
716
71
71 2
2
710
ft
50 100 150 200 250
Bankfull Width = 9.0 ft Bankfull Max Depth = 2.3 ft Floodprone Width > 220 ft
Bankfull Area = 8.1 sq. ft Bankfull Avg. Depth = 0.9 ft Entrenchment Ratio > 24.4
W/D=10
Caldwell Station X-Section #7 (Tibutary #2)
722
720
718
716
714
712
710
ft0
714
712
710
708
706
704
702
ft0
50 1 w ?., .....
Bankfull Width = 15.3 ft Bankfull Max Depth = 3.4 ft Floodprone Width > 260 ft
Bankfull Area = 39.4 sq. ft Bankfull Avg. Depth = 2.6 ft Entrenchment Ratio > 17.0
W/D = 5.9

?d
HI. ?. ?? NCEEP Caldwell St. Creek
Restoration Site - Mecklenburg Co., NC Figure 12. Cross Sections, Existing Conditions
Caldwell Station Ck. and Assoc. Tributaries
Jan. 2004
50 100 150 zoo
Bankfull Width = 7.3 ft Bankfull Max Depth = 2.5 ft Floodprone Width > 170 ft
Bankfull Area = 13.2 sq. ft Bankfull Avg. Depth = 1.8 ft Entrenchment Ratio > 23.8
W/D = 4
Caldwell Station X-Section #10 (between SR21 & 177)
0*0009000*00000.0000000000000000000.00000000
gN , _ z =
r
r .
"? r •??]/ -Sec #3 X-Sep 44
X-Sec #2-,
Kle
y
X- ec #9 X-Sec #1
e `w
Tributary ift
-X-Sec 467.:ft'
WOO f..
tishi
Omi
'S vim ' m_s? ? Y' k lL . _.
0
;
v f
0-w ? •f-
i ??? _ r??
V
?? ? ? ? ?? ?"" ? ,?+j ' ^ fir` .:-• - ;.; y? - . ?? • A "` ' `?
' 81
01
%
"Or
01
Legend
Existing Channels = Sewer Line
Debris Blockage 10 ft Contours
Existing Wetlands* 2 ft Contours 0 50 100 200 400 ft
Parcel Boundaries
Existing Transitional Wetlands
X-Section *Jurisdictional wetland criteria subject to verification
AHI A! and NCEEP Caldwell Station Creek Figure 13. Planform View of Existing Mar.
: Restoration Site, Mecklenburg Co., NC Stream Channels and Wetlands* Pea.:aa.. - -
x A
W I
Legend of Vegetation Cover
1 Mixed Hardwoods Uplands
2 Pine & Mixed Hardwoods Upland
3 Bottomland Hardwoods & Pine Floodplain
4 Loblolly Pine Planting Floodplain
5 Bottornland Hardwood Floodplain & Potential Wetland Inclusions
6 Former Beaver Pond & Potential Wetland Inclusions
-� 7 Mixed Bottomland Hardwoods Floodplain & Wetlands
8 Mixed Bottomland Hardwoods Floodplain & Potential Wetland Inclusions
050 100 200 400 ft 9 Mixed Bottomland Hardwoods Floodplain
10 Sewer right-of-way
,a, NCEEP Caldwell Station Creek
" Restoration Site, Mecklenburg Co., NC Figure 14. Planview of Plant Communities Mar. 2004
mnErvr nw�� i

Ili • • • • • • • • • • • • • • . • • • • • • • • • • • • • • • • • . • ? ? • • • • . • . •

r
st -
'rs
IF>--j l
Legend
Restored Streams .-- Sewer Line
Enhanced & Protected Wetlands - 10 ft Contours
2 ft Contours
Restored Transitional Wetlands Parcel Boundaries 0 50 100 200 400 ft
Restored New Wetlands - X-Section
and NCEEP Caldwell Station Creek Figure 15. Proposed Stream & Wetland
Restoration Site, Mecklenburg Co., NC Enhancement & Restoration: March 2005
IFNANC
fi Planform View
3aC. /
r,- ?.

0+00 G?eey--
A .
Spa ?v?e?? a+53
;
GO "e\\
;
T2-1
•
•
•
•
•
•
•
•
1
Photo T2-3
1
f'
i
et Noe
Qo?i
i
i'
0 50 100 ft
approx. scale
0
•
0 and
O HAF-A1
• ASSFSSWENT a F_
RFTORATEOh
• _JL
0
1•
i
1000
0+81
1+51
2+63
Reach
Photo T2-5
_ 3+62
/
//
/
/
/
/ 1
4+49 .?
Photo T2-6 , ,r7
2+96 4+32/ / 4+67
/'
/
\?rN.,
?0 /
/
Photos are found at end of Appendix B
Areas of dimensional restoration,
riffle enhancement, grade stabilization
Areas of bank stabilization & meander
ftw# habitat improvement (e.g. root wads)
,0' 420' Enhancement
Or"
' 3+32
-
' 2+35 2=80
e-,,-
Wft
Photo T2-4
C EEP Caldwell Station Creek
Restoration Site, Mecklenburg Co., NC
Figure 15a. Proposed stream enhance-
ment along 420' reach of UT to Caldwell March 2005
Station Creek (Trib.#2)
I•
•
•
•
•
•
?Ifp\•? ,90 / 1
\ 1850 1950
1
0
20
?
0
0
TOD 1750 1800
1650
I
1600
' ?50 151
0
l

/
-?5?00 Tie-In, Sfa. 2179.20'
Tie-In', Sta. 1645.88

SS Sta. 114.4 ftripn
f 1 1 50 4700
OUT 705.03 stream lenr= 81 ?200
14
1
1 i

9
50
/
750 18100 j8 p 1900
v 1500
29DO 2050
1 TO
C04 13??
8.58
C. k v-
0 liv, 300

12
6/ ?150
i

"
50 ta. 0+00
LEGEND
ie-in'Trib. #1
LOW BANK, OVERFLOW AREA
00
851
BERM
750
joo -700

FILL CHANNEL, CREATE SLOUGH
CREEK CL STATIONING 0000
10 ca Y SANITARY SEWER

Cs 60 ADJACENT PROPERTY LINE
-9+0&0 -?-'50 a RADIUS OF CURVATURE cn G
%50 14 50

00
50 25- cs
EXISTING STREAM EDGE
00 .00
50
100 Confluence Tn'b. #2, Sta. 0+00

20 240 160 80 0 160 320
Scale in feet
FIGURE 15b.
SEEK RESTORATION SITE
COUNTY, NC CHANNEL RESTORATION PLANFORM MAP JUNE 2005
OVERVIEW

Al'
Trib.#1
50
on
?
Stream ?ngt608.83
1150
I 100
u50
J00 051
950 gSS
0 I
9R *a
- 71,
-Boo
750
00
150 M
*W
K
50'55Q
a0
` ao0
400
5
" 94
d
Caldwell Station, S 00 1900 ZOO 17
- Confluence Trib. #2, Sta. 0+00
Invert'IN'
Elevation
705.58

950 2050 Y1 • _.21S,;
1650
15001 Tie In, 1.2179.20'
.450
1350 1,10 Tie In', Sta. 1645.86
N+*
14,
w ?.
13W' 1
ate w.' 1300
120t??50
C :: ? --- Z *?--
.4700 yp
1750 1800 1450 1900 19
7
/ 2ppp
Z,z
LEGEND
BRUSHMAT
RIFFLE
CROSSVANE
VANE
CREEK CL STATIONING 2000
SANITARY SEWER
ADJACENT PROPERTY LINE
EXISTING STREAM EDGE
320 240 160 80 0 160 320
Scale in feet
HFa?,T NCEEP CALDWELL STATION CREEK RESTORATION SITE Figure 15c.
CHANNEL RESTORATION PLANFORM MAP JUNE 2005
As'CS'WENTAVD MECKLENBURG COUNTY, NC
PEt °:_ I NSTREAM STRUCTURES
•
•
•
•
•
•
•
•
•
•
•
•
•
II•
•
•
•
• 1
•
•
•
•
• C1
• 725
• 720
• 715
• 710
• 705
700
Al UT.#2
1710.5' Q St.a1257)
725
720
715
710
705
100
Cross Section A
A2 A3 Caldwell St. Ck. A4
(709.4' @ St.#1329')
I I I 3-s sg n l
11 sqft BSqft 21 sgft Bank Levee 55sgft
IIIIIIIIIIIIIIIIIIIIIIIIII .. - I ?,.:rm „?."., r'r ? ` -'---
?I'h9?G1?/9999? _ _ :. :.,?. Ilnllllnlllllll
1' depth
Bankfull Bench V -
A
0 50 100 150 200 250
61 UT12 62 Caldwell St. Ck.
(711 4 G^- St.41471, (710 4 ' (P St ?U00'i
725
720
715
710
705
700
Cross Section B
B3
I
11 sgft 8sgf1
Wetland Berm 70 sq h
IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIII III IIIIIIIIIIIIIIIIIIIIII III 30 sq lpti _. _. _. tlNHl? i..l t.'.;..? 111111111111111111111111111111111111111111
1' depth ?? "?EeJeA/ i
Bankfull Bench ?-
1 ?
A
0 50 100 150 200 250
Cross Section C
'E UT #2 1 Caldwell St. Ck. C2 UT.#1 C3 C4
(709 4 @ St.u614') (707.2' ® St #614') (708 0' @ St.w69 )
I I I 1 1
50 sq fl 13 sq ft 3-4 sq h 10 sq h
7sgf1
ypuullllluulllllllllll _ luu1u1111uuuullllnlllll111111nun11 70 sq@
? f?x? ... _ .. _?.\_ IIIIIIIIIIIIIIIIIIIIIIIII IIII IIIIIIII IIIIIIIIIIIIIIII IIIIIIIIIIIIII II IIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIII IIII II II IIIIIIIIIIIIII III111111
-IF
2sgn
IIIIIIII III IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII111IIIIIIIIIIIIIIIIIIIIIII IfI 7p
I
• 0
•
•
•
•
•
•
•
•
•
•
•
HABITAT and
• ASSESSMENT AND RFSroaarlon
• Pr:oc?An, ,
50 100
Existing Topography (Sanborn 2004)
Channel,Levee & Wetland Berm Fill Areas
New Bankfull Channel Cut Areas
New Floodplain Bench Cut Areas
NCEEP Caldwell Station Creek
Restoration Site,
Mecklenburg County, NC
150
A
200
Piedmont Hillslope Wetland Habitat
IIIIIIIIIIIII Bottomland Floodplain Hardwood
Wetland Habitat
Bottomland Floodplain Levee Wetland
Habitat
250 300
Transitional Bottomland Slew to Floodplain
Hardwood Wetland Habitat
Riparian Bank ShrublTree Habitat
Figure 16a. Design Cross Sections (see Fig. 15 for the locations)
Wetland and Riparian Habitat Zones
Cut and Fill Areas Superimposed on 2004 Topography
350

May 2005
_J
CALDWELL STATION CK.
Constructed 9' high bank levees INFLECTION ZONE SECTION
20.0'
55-60 ft2
1 3.8' 1
1.5
CALDWELL STATION CK.
MEANDER BEND SECTION
27.0'
65-70 ft2
4
UT#2 TO CALDWELL STATION CK.
INFLECTION ZONE SECTION
11 ft2 9 ft2
11.0'
9.0'
i
2.0' ,
1.5
I
Planting Zones for Bottomland Planting Zone for Planting Zones for Bottomland
Hardwoods & Wetlands Riparian Banks Hardwoods & Wetlands
12" soil lift wrapped in coconut-
Stapled matting (e.g. SC150) _- -? straw matting (e.g. SC150)
12" Coir fiber logs, staked into Brush mattress laid 3'
cohesive channel substrate into bank, see planting table for
species
Riffle zones augmented with Footer stones to be used under
river cobble (D84; sized for immobility)
coir fiber logs along outer meanders
NCEEP Caldwell Station Creek
H^^T and Restoration Site, Figure 1 6b. Channel Cross Sections May
M ^ Detailed Schematic 2005
R,.,?.°' eK Mecklenburg County, NC
Pvcx? --

715
J
713
0
a
m
c 711
0
CO
0
W 709
Caldwell Station Creek Longitudinal Profile
RT2 R20 R19 R18 R17 R16 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 RT1
O
cz
L
7
U7
707
f6
3
705
2250 2000 1750 1500 1250 1000 750
Stream Thalweg Distance above Hwy 21 Culvert (ft)
Unnamed Tributary to Caldwell Station Creek (UT#2) Longitudinal Profile
715
OW LJV
H11 R31 R30 R29 FY[B K21 HCti R[O ITL4 Ff[:1 Y{[[ FI[1 M[U M1N M1C Hl/ Mlp nib niw nib ni[ j j j no j nu j j j i •••
J
U)
m 713
0
c 711
O
_O
W
m 709
O
CU
'C
7
O 707
c0

705 L-
1750
1500 1250 1VUU /JU DW cw v
Thalweg Distance above Hwy 21 Culvert (ft)
v

A
5-? ° tt
Pnnr..w... .. -ZA NCEEP Caldwell Station Creek
Restoration Site, Mecklenburg County, NC Figure 17. Restored Longitudinal Profiles,

Caldwell Station Ck. and UT#2 May 2005
.01 .I 1 10 loo
1000
;Zzi
sze13cm
100
O O O
O O
O O O
E
'° _ go
O
F O
000
Oq00?0 ,
'c - O 0
1
z O O
O
N
0
0 0
OCOD
1 O 0 (K) (data of Leopold et al., 1964)
.001 .01 .1 1
TC = CRITICAL SHEAR STRESS (tbs./sq. ft.)
O
O
O
O
O
O
Q)
4j
N
N
U
10

100
NCEEP Caldwell Station Creek Figure 18. Shield Curve with Range
" Restoration Site, of Conditions for Caldwell Station May
2005
R-1 ..Tllm Mecklenburg County, NC Ck. and UT#2 Restoration Reaches . I. 1A PRAM ,.. --
EM 1110-2-1418
31 Oct 94
70
50
40
30 DEPTH
OF FLOW
20 roe
? ?0 A
} sn
O 10 _
J
7
5
a
3
2
1
0.1 0.2 0.3 05 1 2 3 5 10 20 30 50 100 200 300 500 mm
i- f`- 1
0.01 0.02 000 0.10 0.20 0 50 2 1:
BED MATERIAL (;RAIN SIZE. D50
Example of allowable velocity-depth data for granular materials.
From USACOE 1994 Appendix A and B.
Range of estimated velocities for Caldwell Station and UT#2 bankfull storm plotted on the Mean Velocity
vs Bed Material Size (D 50) chart from the USACOE 1994 guide to stream stabilization.
NCEEP Caldwell Station Creek Figure 19. Sediment Stability Curve May
Restoration Site, (USACOE 1994) shown with estimated
n u,.sM 4?, yFF 2005
R'-""N^""" 1f T. Mecklenburg County, NC mean velocities for restoration reaches
PNOGN/M ir<
............................................
100
90
C: 80
M
4--r 70
L
60
50
M
:3 40
E
U 30
o
OR
20
10
0
LOCALITY Caldwell Station Reach - Typical Bar Grain Size Sample
SITE Sample CS-BA
S A N D C 0 B B L E BOULDER
SILT v, fine fine medium coarse v. coarse
? ? ? ? ? I fr

1.5

A

.01 . 1 Particle Size (mm) 1 1 0 10 0 1000
6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10
Particle Size (phi)
D84(min) 0.4 mm
D50 0.8 mm
D84(max) 1.5 mm
NCEEP Caldwell Station Creek Figure 20a. Grain size curve for Typical

R- -
Restoration Site, Mecklenburg County, NC
Bar (Existing Conditions) Caldwell St. Ck. May 2005
Pv _,

100
90
80
ca
4-J 70
L
60
N
! 50
M
:3 40
E
U 30
01
0
20
10
0
LOCALITY Caldwell Station Reference Reach - Bar Grain Size Samples
SITE Samples CSR-BA, CSR-BB, & CSR-BC
S A N D C O B B L E BOULDER
SILT v. fine fine medium coarse v. coarse
- H I ? 1 e- BA
_ -BC
8.0

4.2

1 1 2

L- I.-J- 1
.01 . 1 Particle Size (mm) 1 1 0 10 0 1000
6 5 4 3 2 1 0 -1 -2 3 -4 -5 -6 -7 -8 -9 -10
Particle Size (phi)
D84(min) 1.26 mm
D50 4.5 mm
D84(max)
7.3 mm
and NCEEP Caldwell St. Creek Figure 29b. Grain size curves for Typical May 2005
R#1r
:
T Restoration Site, Mecklenburg County, NC Bars - Reference Reach (W. Fork Reeds Ck.)
M ..
PFx

100
90
80
Ca
a-J 70
i
N
60
N
! 50
M
E 40
V 30
0
"
20
10
0
LOCALITY Caldwell Station Reference Reach - Riffle Substrate Grain Size Samples
SITE Samples CSR-RA, CSR-RB, & CSR-RC
S A N D C O B B L E BOULDER
SILT v. fine fine medium coarse v. coarse

I I
7.5

Q 2.51

/
1.1 \
v
i
_
I
_

?
--
-

.01 . 1 Particle Si ze (mm) 1 10 10 0 1000
6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10
Particle Size (phi)
D84(min)
1.0 mm
D50
3.17 mm
D84(max)
6.8 mm
Riffle Armor
D50: 17 mm
D84(max): 28 mm
and NCEEP Caldwell Station Creek Figure 20c. Grain size curves for Typical
H.e...-

R.,..:?.
Restoration Site, Mecklenburg County, NC
Riffles Reference Reach (W. Fork Reeds Ck.) May 2005

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APPENDIX A
Appendix A
Vegetative Cover and Approximate Wetland Limits
List of Figures
Page
Figure A 1 Map of Vegetative Cover and Photo Stations ..................... 4
Figure A2 Area 1, Photo # 12, Mixed Hardwoods Upland .................... 5
Figure A3 Area 2, Photo # 11, Pine and Mixed Hardwoods Upland ............. 5
Figure A4 Area 3, Photo # 8, Bottomland Hardwoods with Pine Flood Plain ..... 6
Figure A5 Area 4, Photo # 7, Loblolly Pine Planting Flood Plain .............. 6
Figure A6 Area 5, Photo # 5, Mixed Bottomland Hardwoods Flood Plain........ 7
Figure A7 Area 6, Photo # 2, Former Beaver Pond .......................... 7
Figure A8 Area 7, Photo # 16, Mixed Bottomland Hardwoods Flood Plain....... 8
Figure A9 Area 8, Photo # 15, Mixed Bottomland Hardwoods Flood Plain....... 8
Figure A10 Area 9, Photo # 14, Mixed Bottomland Hardwoods Flood Plain....... 9
Figure A11 Area 10, Photo # 18, Mixed Bottomland Hardwoods Flood Plain ..... 9
Figure A 12 Map of Approximate Jurisdictional Wetland Areas ................. 10
•
•
•
•
• CALDWELL STATION CREEK
•
• Vegetative Cover
•
Area 1 is illixe(I I lardwoo(Is Upland with an average diameter breast height (dbh) of 10". The
canopy contains Sweetgum (Liquidambar styraciilua) to 14"dbh, Green ash (Fravinus
• pemmsylvanica) to 14" dbh, American elm (Uhns americmma) to 18" dbh, Persimmon (Diospyros
vigmniana) to 12" dbh, Red maple (Ater rubrunm) to 18" dbh, Sycamore (Platanus occidentalis)
to 14" dbh, White oak (Querctts alba) to 14" dbh, Southern red oak (Q. falcata) to 30" dbh,
• Swamp red oak (Q. shunmardii) to 40" dbh, and Hackberry (Celtis laevigata) to 12" dbh. The
• subcanopy and shrub layers are poorly developed, but do contain Cane (Arundinaria gigantea)
and Autumn Olive (Elaeagnts umbellata). The largest trees are situated in the western corner of
this area. See Figure A2.
•
Area 2 is Pine and Mixed Hardwoods Upland with an average dbh of 8". The canopy is
• dominated by Loblolly pine (Pints taeda) to 12" dbh, with Sweet gum to 8" dbh, Sycamore to
10" dbh, and Red maple to 10" dbh. The subcanopy contains Red cedar (Juniperus vimginiana)
• to 8" dbh, Tag alder (Alnus serrulata) and Pawpaw (Asintina triloba). The shrub layer is open
• and contains Cane and Autumn Olive. Vines are Catbrier (Smilax spp.). See Figure A3.
• Area 3 is mixed Bottomland Hardwoods with Pine Flood Plain and has an average dbh of 8".
• The canopy is fairly open and contains Sweet gum to 16" dbh, Yellow poplar (Liriodendron
tulipifera) to 10" dbh, Black walnut (Juglands nigra) to 10" dbh, Wild cherry (Primus serotina)
• to 8" dbh, and Loblolly pine to 16" dbh. The subcanopy contains Red cedar. The shrub layer is
• open to dense with Privet (Ligustrum sinense), Cane, and Tag alder. See Figure A4.
Area 4 is a relatively young Loblolly Pine Planting; Flood Plain with an average dbh of 6".
• The stand is Loblolly pine to 8" with a subcanopy of young hardwoods. See Figure A5.
Area 5 is a relatively young, even aged, mixed
• , with an average dbh of 6". The canopy is dominated by Sweet
. gum to 14" dbh, and Yellow poplar to 10" dbh, with Sycamore to 8" dbh, Willow oak (Q.
phellos) to 6" dbh, Red maple to 12" dbh, American elm to 8" dbh, and Black willow (Salix
nigra) to 12" dbh. A few Loblolly pines to 12" dbh are scattered within the canopy. The
subcanopy and shrub layers are absent. Standing water and a de-watering ditch are also in this
• area. See Figure A6.
•
•
•
•
•
•
•
•
•
•
0
Area 6 in an old
which was drained a
year or more ago. It is dominated by grasses and sedges with a fringe of small caliper trees and
shrubs around the perimeter. These are dominated by Black willow with Silky dogwood
(Cornus anmonnun), Arrow wood (Viburnum dentatum), Tag alder, Red maple, Green ash, and
Elderberry (Sanmbucus canademsis). See Figure AT
Area 7 is , with an average dbh of
8". It is dominated by Red maple to 10" dbh, with Black willow and Green ash also present in
-2-
the canopy. The shrub layer consists of Tag alder, Arrow wood and Silky dogwood. See Figure
A8.
Area 8 is , a
swale-like area below the Beaver dam. It is comprised of even aged small caliper trees with an
average dbh of 4". The canopy contains Black willow to 10", Green ash to 4" dbh, Red maple to
3" dbh, Sycamore to 4" dbh, and a few scattered Loblolly pines to 10" dbli. The shrub layer
contains Tag alder and Button bush (Cephalanthus occidentalis). See Figure A9.
Area 9 is Mixed Bottoniland Hardwoods Flood Plain, has a fairly open canopy dominated by
Green ash with an average dbh of 8". The canopy contains Green ash to 8" dbh, Sycamore to
12" dbh, Red maple to 24" dbh and Yellow poplar to 10" dbh. The subcanopy consists of Red
maple to 8" dbh. The shrub layer contains Black berry (Rubes spp.), Cane and Arrow wood.
See Figure A10
Area 10 is ,
similar to area 8. It is comprised of even aged small caliper trees with an average dbh of 4". The
canopy contains Black willow to 6", Green ash to 4" dbh, Red maple to 3" dbh, and Sycamore to
4" dbh. The shrub layer contains Tag alder and Silky dogwood. See Figure A11.
The sewer line that parallels Caldwell Station Creek is overgrown with small caliper trees, Black
berry and Japanese honeysuckle (Lonicera japonica).
The power line right-of-way is overgrown with a number of small caliper weedy species such as
Sweet gum and Black locust (Robinia pseudo-acacia).
The undisturbed creek bank is lined with trees that range is size from small shrubs to 30" dbh,
with an average dbh of 12" to 14".
-3-

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00
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3
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??,v.?3"? d0 _ . F ??? s ??,..77 8. JO . M$
u
r
X50', .r 'III c1 +
ter` ?.? .? ?'- .? •.?:'? .:+?;- ? ? „i? ?y?, rt ^w•
,• ^..r . "7 x -?,?i,,•? "ice
ell
! 6.07`"?-T?S? w4"?! , rsa. a 'T c r? IO
A
.
_ B ss *fee
? • ? .7.c ?' ?! f -yam ,t ?••• { ?... w 7.? ^ T O
t r?" r ?s 1ID ??? "' R
" CALDWELL STATION CREEK
Vegetative Cover
and
i , Phot o St at ions
11 Vegetation Areas e? 25 Photo Direction and Number
K,lE vl ENE:URi3 ='JNTr X31
-5-
Figure A2 Area 1, Photo #12, Mixed Hardwoods Upland
Figure A3 Area 2, Photo #11, Pine and Mixed Hardwoods Upland
-6-
Figure A4 Area 3, Photo #8, Bottomland Hardwoods with Pine Floodplain
Figure A5 Area 4, Photo #7, Loblolly Pine Planting Flood Plain
-7-
Figure A6 Area 5, Photo #5, Bottomland Hardwood Flood Plain
Figure A7 Area 6, Photo #2, Former Beaver Pond

.A A

Figure A9 Area 8, Photo #15, Mixed Bottomland Hardwoods Flood Plain
w
?r
-8-
Figure A8 Area 7, Photo #16, Mixed Bottomland Hardwoods Flood Plain
Figure All
f f ?

V
vYj ?F4 ?'?j}? ? ???
.r ?1 5J ?, ?- 1 1 E
-9-
4
A 11 ..
t4i

Figure A10 Area 9, Photo #14, Mixed Bottomland Hardwoods Flood Plain
Area 10, Photo #18, Mixed Bottomland Hardwoods Flood Plain

oil
aro
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POW
R
CALDWELL STATION CREEK
?'`°a Approximate Wetland Limits
NOTE: This map is for discussion and survey purposes only, and
is subject to US Army Corps of Engineers verification.
pit, Mixed is a complex mosaic of wetland and non-wetland, with hydric soils
'I„ found just below 12 inches in the non-wetland areas.
APPENDIX B

r ? 'e
1 ?. ear. ? Z _?.
j
Caldwell Station Main Reach between I-77 and Interstate 21 looking upstream
t NS . ?
(• ?, ?-f
it 4 '?"AE .%1 ?- ?? r.
y

',fir ? ?. ••v ? -.? r
Caldwell Station Main Reach -- 550 ft upstream of Interstate 21 culvert
t{/ 'k --
t
,: `-.-'l
upstream

-2-
Caldwell Station Main Reach -1000 ft uNream of Intestate 21 culvert looking upstream
Caldwell Station Main Reach -1700 ft upstrearn of Intestate 21 culvert looking upstream

%
t i? _ R f" s
y T
Pft
.a -
Caldwell Station TiibuLuy # I - 1200 tt upsUea -n of cmtluence with Gildwell Station looking upstuuun
-3-
Caldwell Station Tributary #1- 375 ft upstream of confluence with Caldwell Station looking downstre n

[ J 4-'s
F
41

Y
' r
?• r .. ?•
•Y. - y ? ei./.l
-4-
i
rA

Caldwell Station Tributary #2 - 200 ft upstream of confluence with Caldwell Station looking up5uam
1AY?? ? C 1 ? .'fIa
7 F '! 77,x'1 !?'. y y? i. ? •, S "L'1rt' ? l
`r+h yr'r #i{i?.'n.tt r V frti
?t r-.. Ir ...rj 1•^ t Yom.., 'r? A f?? y w
• ??' v. i,rv SA 4i its
4N,
Cakk cll Station •I Y1hL1tary #I 1ZcIIc. I)clvrccll 1 77 and Interstate 21 looking upstream
-5-
Caldwell Station Tributary #1 Relic, between I-77 and Interstate 21 looking downstream
r
?i-
.w

Photo T2--1, South UT to Caldwell Station Crk. Looking downstream to confluence

-- -- ,,
r. - ;,
?i
r
WM-
Photo T2-2, South UT to Caldwell Station Crk. Looking upstream.
-6-

3
r`
r?
1yr T
.?, = £y
I RAW
?a. r k ? ?Y k '-?'•'. 7?
41
Photo 1'2-3, South UT to Caldwell Station Crk. Looking upstream.

T? ha
LR ? _ ?' ?, ' k ` ? f day
7k?? fir ?-
au,
.;
004

Photo T2-4, South UT to Caldwell Station Crk. Looking upstream at debris jam.
-7-
'VIM,

'J
. r .

Photo T2-5, South UT to Caldwell Station Crk. Looking downstream at debris jam.
f°

S" ar f ' ? l
a
INI
? t
ski"• ?t
c ?i A-mi"
1
Photo T2-6, South U'l to Caldwcll Station 0-k. Looking upstream to property line.
zp?,*
F
yy S .\
-8-
APPENDIX C
•
•
•
•
•

Watershed Study No. 6
McDowell Creek Watershed
Preliminary Engineering Report
MCSWS Project No. 28001
January 2002
Prepared For:
•
• C'ar'ora•hte:tter??,ro
STOR01
_
-a- WATER
a Services v
McDowell Creek Watershed Preliminary Engineering Report
Prepared By:
Watershed Concepts
A Total Water Resource
6201 Fairview Rd., Suite 400
Charlotte, NC 28210
MECKLENBURG COUNTY
STORM WATER SERVICES
PRELIMINARY ENGINEERING REPORT
FOR
MECKLENBURG COUNTY MITIGATION PLANS
MCDOWELL CREEK WATERSHED
ACKNOWLEDGEMENT
The project staff of Watershed Concepts, a Division of HSMM, Inc., would like to give thanks to
Mecklenburg County Storm Water Services (MCSWS) for its assistance and support during this
project.
DISCLAIMER
This watershed-wide study is for planning purposes only. These study results and
recommendations are preliminary and should not be used for construction without additional
detailed engineering design analysis.
CERTIFICATION
I hereby certify that this Preliminary Engineering Report for Mecklenburg County Mitigation
Plans was prepared by me or under my direct supervision.
Signed, sealed, and dated this 1 l th day of January 2002.
By:
Joseph B. Chapman, P.E.
Senior Vice President
SEAL
20500
B. CNPr`•
McDo" ell Creek Watershed Preliminary Engineering Report 11
•
MECKLENBURG COUNTY
STORM WATER SERVICES
PRELIMINARY ENGINEERING REPORT
FOR
MECKLENBURG COUNTY MITIGATION PLANS
MCDOWELL CREEK WATERSHED
TABLE OF CONTENTS
Executive Summary .......................................................................................................................1
1. General Watershed Conditions ...........................................................................................7
1.1 Watershed Characteristics .........................................................................................7
1.2 Development in the Watershed ...............................................................................10
1.3 Aquatic Habitat and Environmental Monitoring .....................................................15
1.4 Rosgen Applied River Morphology Assessment ....................................................17
1.5 Bank Stability Problem Identification. ....................................................................18
2. Benefit:Cost Economic Analysis ......................................................................................19
2.1 Riverine Flood Model Overview ............................................................................. 19
2.2 Economic Data ........................................................................................................ 19
2.3 Hydraulic Data ........................................................................................................ 20
2.4 Modeling Process .................................................................................................... 20
2.5 Economic Analysis .................................................................................................. 20
2.6 Improvements .......................................................................................................... 21
3. Flood Hazard Mitigation ...................................................................................................22
3.1 FEMA Regulated Stream Service Requests ............................................................22
3.2 Repetitive Loss Structures .......................................................................................22
3.3 Permanent Storm Water Easements ........................................................................22
3.4 Roadway Overtopping Problem Locations .............................................................22
3.5 Flood Mitigation Improvement Analysis ................................................................24
4. References ...........................................................................................................................31
McDowell Creek Watershed Preliminary Engineering Report 111
0
LIST OF TABLES
Table E1 Structures with ECF Flooding Potential in McDowell Creek Watershed ..................2
Table 1 Development in the McDowell Creek Watershed ....................................................11
Table 2 MCDEP Water Quality Monitoring Summary .........................................................16
Table 3 Rosgen Level 1 Classification Parameters - McDowell Creek ................................17
Table 4 Service Requests in McDowell Creek Watershed ....................................................22
Table 5 Roadway Overtopping Problem Locations ..............................................................23
Table 6 Summary of the Benefit:Cost Analysis for the Four Mitigation Project Areas .......25
Table 7 Structures Within Existing 100 Year Floodplain .....................................................25
Table 8 Mitigation Measures for Henderson Park/Leisure/Lullwater Neighborhood ........... 27
Table 9 Mitigation Measures for Gilead Neighborhood .......................................................28
Table 10 Mitigation Measures for Cumbira/Stonegreen Neighborhood .................................29
Table 11 Mitigation Measures for Delancey Neighborhood ...................................................30
McDo"eII Creek Watershed Preliminary Engineering Report iv
LIST OF FIGURES
Figure E1 McDowell Creek Watershed ...................................................................3
Figure E2 Overall Project Areas - Map 1 ................................................................................. ..5
Figure E3 Overall Project Areas - Map 2 ................................................................................. ..6
Figure 1 At Statesville Road ................................................................................................... ..7
Figure 2 Near Beatties Ford Road .......................................................................................... ..7
Figure 3 McDowell Creek Near McDowell Trib 1 ................................................................ ..8
Figure 4 Torrence Creek Trib 2 near McDowell Creek ......................................................... ..8
Figure 5 Caldwell Station Creek at Statesville Road .............................................................. ..8
Figure 6 Torrence Creek Trib 1 at Bradford Hill Lane .......................................................... ..9
Figure 7 Near Westmoreland Road ........................................................................................ ..9
Figure 8 At Glenwyck Lane ................................................................................................... ..9
Figure 9 At Stawell Drive ....................................................................................................... 10
Figure 10 At Bradford Hill Lane .............................................................................................. 10
Figure 11 Gilead Road Crossing ............................................................................................... 10
Figure 12 At Leisure Lane ........................................................................................................ 11
Figure 13 Example of Proposed Greenway Trail ..................................................................... 12
Figure 14 Greenway Trails and their Relationships to Potential Flood Areas ......................... 13
Figure 15 Summary of the Cit}-County Capital Improvement Projects .................................. 14
Figure 16 Road Overtopping Location Map ............................................................................. 24
Figure 17 Houses with Flooding Potential in Henderson Park/Leisure/Lullwater
Neighborhood .......................................................................................................... 27
Figure 18 Houses with Flooding Potential in Gilead Neighborhood ....................................... 28
Figure 19 Houses with Flooding Potential in Cumbria/Stonegreen Neighborhood ................. 29
Figure 20 House with Flooding Potential in Delancey Neighborhood ..................................... 30
McDoeell Creek Watershed Preliminary Engineering Report v
GLOSSARY
Term used in this report Definition
100-year Flood The flood that has a 1% probability of being equaled or
exceeded in any given year.
Base Flood Elevation (BFE) Water surface elevation for the 1% probability flood (100-
year flood).
Existing Conditions The land use condition of the watershed based on the state
of development as of the date of this study.
Existing Condition Floodplain (ECF) The floodplain delineated for the I% probability flood
(100-year flood) using the current land use conditions in
the watershed (existing conditions).
Flood Fringe Areas A buffer area bounded by thc- ECF (elevation of the BFE)
and a point where the land elevation if 2 ft above the BFE.
Future Conditions The land use condition of the watershed based on the
projected ultimate buildout in the watershed.
Future 100-year Flood The flood that has a 1% probability of being equaled or
exceeded in any given year under the fixture conditions of
land use
Future Condition Floodplain (FCF) The floodplain delineated for the 1% probability flood
(future 100-year flood).
MCSWS Mecklenburg County Storm Water Services
MCDEP Mecklenburg County Department of Environmental
Protection
NALGEP National Association of Local Government Environmental
Professionals
CMUD Charlotte-Mecklenburg Utilities District
McDowell Creek Watershed Preliminary Engineering Report vi
EXECUTIVE SUMMARY
MCDOWELL CREEK WATERSHED
This Preliminary Engineering Report briefly describes a study of McDowell Creek morphology,
bank stability problems, flood hazard areas, and potential mitigation measures. Public records
from the Mecklenburg County website, aerial photographs, interviews with public officials, and
specific references listed at the end of this report have been consulted in preparation of this
report. The gathering of information has been supplemented by several field visits, surveys, and
photography of the areas under study.
Currently, the McDowell Creek watershed, shown in Figure E1, is not as highly developed as
some of the other sections of Mecklenburg County. However, rapid development is visible
virtually everywhere in the watershed, and conditions in this drainage basin will soon resemble
those in other highly developed sections of the County. This watershed includes the tributaries
of Caldwell Station Creek, Torrence Creek, Torrence Creek Tribs 1 and 2, and McDowell Creek
Tribs 1 and 2.
McDowell Creek and its tributaries are in reasonably stable condition due to four main factors:
1. Stream banks stabilized by riprap or other means to safeguard a sewer main line that extends
along the creek
2. Heavily vegetated banks and floodplains
3. Numerous road crossings and other man-made structures which form grade controls that limit
stream scour and head-cutting
4. Past stabilization efforts along McDowell Creek and its tributaries
Flooding potential within the existing 100-year floodplain (ECF) can be identified in four
general neighborhoods along McDowell Creek. A total of 15 residential structures are affected,
none of which experience inundation because the finished floor elevations are above the BFE.
All structures are located in the flood fringe areas (within 2 ft of BFE) as shown in Table E1. All
structures are post-FIRM (built after 1981) and are shown in Figures E2 and E3. Three
mitigation measures were considered for the four neighborhoods shown in Table E I and Figures
E2-E3: elevating the structures two feet above the BFE, berm construction, and acquisition.
McDowell Creek is approximately 9.2 miles long with an additional 10.3 miles of tributaries
flowing into the creek. The watershed extends in a general northeast to southwest direction
within the boundaries of the City of Huntersville, which is north of the City of Charlotte.
McDowell Creek discharges into the Catawba River in the west side of Mecklenburg County,
upstream of Mountain Island Lake, which is the primary source of Charlotte's drinking water
supply. The banks and floodplains of McDowell Creek and its tributaries are densely vegetated
and in some parts heavily wooded, creating a stable stream. The flow is mostly shallow and
tranquil in a well-defined channel with relatively steep banks. Compared to other creeks,
McDowell is less urbanized, although the rapid pace of development is evident along the stream
%IcDouell Creek Watershed Preliminary Engineering Report
and its tributaries. Frequent occurrence of point bars is indicative of increased sediment
transport due to heavy development activity.
Table E1. Structures with ECF Flooding Potential in McDowell Creek Watershed
No. of
Structures Project Neighborhood/Area No.
Flooded No. within
2ft of BFE Avg. Fld.
Depth* Median
Depth* Highest
Depth* Lowest
Depth*

9 Henderson Park Rd/Leisure Ln/Lullwater Cv 0 9 -0.87 -1.30 -0.11 -1.63

2 Gilead Road 0 2 -1.39 -1.39 -0.86 -1.91

3 Cumbria Ct/Stoneereen Ln 0 3 -0.43 -0.63 -0.08 -0.78

1 Delancey Ln 0 1 -0.01 -0.01 -0.01 -0.01

. Negative numbers maicate tnat the rinisnea boor elevation is above the iuu-yr tlooa elevation; aeptns are in teet.
The Rosgen stream classification system was utilized to provide an initial assessment of the
morphology of McDowell Creek. The majority of McDowell Creek is classified as a type G
channel with some reaches possibly being classified as type F. Generally, the channel displays a
low width/depth ratio, low sinuosity and relatively low channel slope. Indicators of a new
bankful flow line were observed below the historic top-of-bank, which inply that the channel
has incised within the historic floodplain. This has most likely resulted from a combination of
urbanization of the watershed and manual re-grading of the channel. The historic floodplain,
which was formed as an alluvial plain bounded by gentle slopes of upland soils, currently forms
a terrace that confines the channel.
McDowell Creek discharges into the Catawba River between the Cowins Ford Dam and
Mountain Island Lake, the primary source of Charlotte's drinking water supply. This location
on the Catawba River is also vital for the cities of Gastonia and Mount Holly, which have water
supply intakes near the mouth of McDowell Creek. This watershed is actively being studied by
various groups, including MCSWS (this study), Local Watershed Management Plan (NC
Wetlands Restoration Program and CH2M-Hill), Water Quality Computer Model Simulation
(MCDEP and TetraTech), and McDowell Creek Watershed Smart Growth for Clean Water
Partnership (NALGEP, Charlotte, Mecklenburg County, Cornelius, Huntersville, Trust for Public
Lands). It is important to note that these initiatives have different objectives, and as each
initiative progresses, the participants are sharing information, communicating, and coordinating
their efforts.
Primary pollutants from land development activities along McDowell Creek and its tributaries
include nutrients, fecal coliform, and sediment. The Mountain Island Lake Marine Commission
has already noted the introduction of Hydrilla (Hydrilla L.C. Rich). A Hydrilla-eating carp has
been introduced to combat the problem. However, the direct cause of the problem stems from
the abundant source of nutrients that fertilize this plant, flowing downstream through the
McDowell Creek watershed. There are various land acquisition programs underway to protect
and buffer the watershed from non-point source pollutants and development, including the Trust
for Public Lands and the Mecklenburg County Park and Recreation Department. Together,
through the Mountain Island Lake Initiative, each is purchasing large tracts of land to be
preserved as open space.
McDoweII Creek Watershed Preliminary Engineering Report 2
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IVcDowcll Creek Watershed Preliminary Engineering Report 3
MCDEP maintains several monitoring stations along McDowell Creek and its tributaries. While
the Macroinvertebrate Taxa Richness sampling and the Fish Bioassesment sampling has
produced Poor and Fair ratings since 1994, the overall Water Quality Index has consistently
ranked as Average, Good and Good-Excellent. The overall water quality has remained generally
consistent in the watershed since 1996. One flow monitoring station, USGS Gage 0214266000,
located at McDowell Creek and Beatties Ford Road crossing, has been in operation since
November 1996.
Presently, there are no major capital improvement projects in the watershed that may affect its
hydrology. There are plans for the construction of approximately 8.7 miles of greenway trail
along McDowell Creek and its tributaries, of which currently approximately 0.7 mile has been
completed. The analyses and mitigation alternatives considered in this report will not be affected
by the planned capital improvement projects of the County.
Flooding hazards for the structures lining the banks of the creek may be identified in four general
neighborhoods affecting a total of 15 structures. All of the structures have finished floor
elevations in the flood fringe areas (within 2 ft of BFE). Inundation damages in the case of a
100-year flood are nonexistent. Three flood mitigation alternatives and a no-action
alternative were considered for the affected structures in the McDowell Creek watershed.
None of the mitigation measures resulted in a benefit:cost ratio greater than 1.0, therefore
no flood mitigation measures are recommended for this watershed.
There are several road crossings that are subject to overtopping in case of a 100-year flood
Flood depths over the roadway may be as high as 6.3 ft in one case for the future 100-year flood
(FCF). Two smaller crossings on non-public roads would also be flooded severely. Several
mitigation measures should be considered for the road crossings of this watershed, which include
warning signs for the approaching motorists, tall guardrails or indicators to guide the vehicles
away from the edge of the road in case of a flash flood, raising the elevation of road at the stream
crossing, and emergency response team notification. Regular maintenance at man-made
structures such as road crossings and storm water outfalls will be necessary to maintain the
stream capacity and stability.
McDowell Creek Watershed Preliminary Engineering Report 4

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McDowell Creek Watershed Preliminary Engineering Report
6
1. GENERAL WATERSHED CONDITIONS
1.1 Watershed Characteristics
The McDowell Creek basin includes a watershed of about 26.3 mi` in the northwestern part of
Mecklenburg County. This basin includes the main stem of McDowell Creek as well as the
adjoining streams of Caldwell Station Creek, Torrence Creek, Torrence Creek Tribs 1 and 2, and
McDowell Creek Tribs 1 and 2.
JlcDoivell Creek
McDowell Creek's main stem is approximately 9.2 miles long. The system flows in a general
northeast to southwest direction north of the City of Charlotte. McDowell Creek discharges into
the Catawba River on the west side of
Mecklenburg County. Due to its distance from
the center of town, existing development along
the river is not as dense as that experienced in
the other watersheds within the city. However,
extensive residential and commercial
development is occurring at the present time.
Under the existing 100-year flood conditions
(ECF), adjacent property suffers from a
flooding potential in a number of residential
sites.
Rosgen classification of McDowell Creek is
presented in Section 1.4 of this report.
Qualitative descriptions of the creek and its
tributaries are given in the following
paragraphs. Similar to the other creeks in the
City of Charlotte, there is a sewer trunk line
along McDowell Creek and its tributaries.
Installation of these trunk lines has resulted in
stabilized banks and trained stream alignment
throughout the length of the McDowell Creek
system. The banks and floodplains are densely
vegetated and in some parts heavily wooded,
creating a stable stream. Figure 1 shows the
stream at its upstream end at Statesville Road
crossing. The flow is shallow and tranquil in a
well-defined floodway with relatively steep
banks. Figure 2 shows the creek downstream,
past the confluence with McDowell Trib 1 at
Beatties Ford Road. The flow in this area is
shallow and tranquil with stabilized banks and
a relatively straight main channel alignment.
The sewer trunk line is on the right bank of the
McDowell Creek Watershed Preliminary Engineering Rcpon 7
Fig.l At Statesville Road
Fig. 2 Near Beatties Ford Road
?,r !.'7

NlcDotieII Creek Watershed Preliminary Engineering Report 8
creek. Vegetation is taking over the riprap and
is dense along the more gently sloped banks in
this section. Compared to other creeks,
McDowell is in a less urbanized setting,
although the rapid pace of development is
evident along the stream and its tributaries.
Frequent occurrence of point bars is indicative
of increased sediment transport due to heavy
development activity.
The McDowell Creek system was observed
under base flow conditions when the photos of
this report were taken. Under the observed
conditions, the flow is mostly tranquil and
shallow. The floodway is lined with heavy
brush and tree growth making access to the
stream difficult in most places, although the
banks must have been disturbed and cleared at
one time for the installation of the sewer main
line. By visual observation, the manholes of
the sewer line seem to be below the 100-year
flood level in many places visited. There is a
greenway along the creek near the intersection
of Bradford Hill Lane and Gilead Road,
further stabilizing the banks and floodplain in
that region of the creek.
The most significant tributary of McDowell
Creek is Torrence Creek. The nature of the
banks, the vegetation, flow conditions, and
floodplain of the two streams are very similar.
Figure 3 shows McDowell Creek further
upstream from where Figure 2 was taken.
Figure 4 shows Torrence Creek Trib 2 near
Gilead Road Crossing. The tranquil nature of
the creek with an occasional point or middle
bar and heavily vegetated banks are similar
conditions in both cases.
Although MCSWS regularly maintains areas
of known flooding problems, the tendency of
vegetation to establish over depositions in the
streambed can affect the hydraulic capacity of
the stream. Figure 5 shows Caldwell Station
Creek at Statesville Road crossing. Deposition
has occurred immediately in front of one of the
two box culverts. Vegetation has taken root
Fig. 3 McDowell Creek near McDowell Trib 1
Fig. 4 Torrence Creek Trib 2 near McDowell Creek
Fig. 5' Caldwell Station Creek at Statesville Road
and now sizable trees and brush line the
deposits. Flood flows may not be able to
uproot the trees and the capacity of the culvert
may be compromised. Figure 6 shows
Torrence Creek at Bradford Hill Lane crossing.
The flow of the entire creek is occurring in the
right barrel of the triple circular culvert. Signs
of vegetation taking root on the deposited
sediments are visible. If floods of sufficient
magnitude that flush the sediments downstream
of the culvert do not occur, more vegetation
may stabilize the deposits and eventually
compromise the capacity of the culvert. In
order to maintain full capacity for the stream
and ensure the safe passage of a flash flood, it
may be necessary for the County to undertake a
stream maintenance program or install
hydraulic structures for sediment exclusion
from the structures at road crossings. The
maintenance program would include keeping
the road crossing free of unwanted vegetation,
other obstructions, and sediment deposits, and
assuring that bridges and culverts will operate
at or near their design capacity during a flood.
Further discussion of a creek maintenance
program will be preserted later in this report.
As mentioned before, the banks and floodplain
of this stream are very well vegetated and
stable. This is clear throughout the figures
shown above, and the remainder of this report.
The typical cross section of the floodway in the
upstream reaches of the creek has vertical walls
and a flat bed (a Usection), about 8-10 feet
wide and about 8-10 feet deep (Figs. 1 and 4).
At its downstream reaches, the floodway
becomes wider and the banks are less vertical,
acquiring side slopes of 1'/z:1 or so (Figs. 2 and
3). The floodplain along most of this stream is
fairly wide and very gently sloping, and
generally heavily vegetated or wooded. The
minimum vegetative cover is thick tall grass.
Occasionally, there are signs of human activity
on the floodplain such as earth moving and
construction. However, unless very current
activity has occurred, vegetation seems to be
able to take hold, and erosion of the banks or
Fig. 7 Near Westmoreland Road
Fig. 8 At Glcnwyck Lane
%IcDowell Creek Watershed Preliminary Engineering Report 9
Fig. 6 Torrence Creek Trib 1 at Bradford Hill Lane
floodplain does not seem to be a serious
problem. The floodplains in two sections of the
creek are shown in Figure 7 (near
Westmoreland Road) and Figure 8 (at
Glenwyck Lane, off Bud Henderson Road).
illcDorvell Creek Tributaries
The tributaries of McDowell Creek, with a
combined total of 10.3 miles, constitute longer
total stream mileage than McDowell Creek's
main stem. The main tributaries are Caldwell
Station Creek, Torrence Creek, Torrence Creek
Tribs 1 and 2, and McDowell Creek Tribs 1
and 2. The general geologic, hydrologic,
climatologic and botanical conditions of these
tributaries are similar to those of McDowell
Creek. As a result, the morphological
characteristics of these streams are also similar.
At a field visit on May 2, 2001 the morphologic
similarity of McDowell Creek and its
tributaries was studied and documented. In
addition to similar morphology between the
main stem and the tributaries, the general
pattern of development along the streams is
also similar. Because of this similarity in
behavior of the entire system, McDowell Creek
and its tributaries are treated as a single unit.
1.2 Development in the Watershed
Development along McDowell Creek and its
tributaries is less interne than other basins of
the City of Charlotte at present. However,
heavy commercial and residential development
activity is underway. Visual judgment based
on the site visit of May 2, 2001 suggested that a
number of residential and commercial buildings
are near or within the floodplain. Four cases of
such structures in the flood fringe areas are
presented in the next four figures, although
sites with flooding potential are not limited to
those shown in these figures. Figure 9 shows
houses on Stawell Drive. These are three of 7
houses whose footprints plot within the ECF.
Figure 10 shows houses on the intersection of
McDowell Creek Watershed Preliminary Engineering Report 10
Fig. 10 At Bradford Hill Lane
Torrence Crossing Drive and Bradford Hill
Lane. Several houses in this neighborhood are
in the flood fringe areas. Figure 11 shows an
older house on Gilead Road. The elevation
certificate for this house places the finished
floor elevation above the BFE. However, the
lower level garage could be flooded. There are
other older houses in the same neighborhood
with footprints in the ECF or the FCF. Figure
12 shows houses on Leisure Lane, off Bud
Henderson Road. In plan view, the entire row
of houses on the creek side of this street is
located within the ECF. There was extensive
development activity with earth moving at the
time of the site visit in this neighborhood.
General statistics of development in the McDowell Creek watershed are summarized in Table 1.
The table includes temporal distribution of development in the watershed as well as the
development type according to the information available as of the year 2000. Table 1 indicates
that about 80% of the parcels in the basin are in single-family or other residential categories and
about 14% of the parcels are still undeveloped (as of the year 2000). The table also indicates the
accelerating pace of development in the watershed since about one third of the parcels were
developed in the 1990's.
Table 1. Development in the McDowell Creek Watershed*
Year Developed

Before 1970
1970-1979
1980-1989
1990-
2000
Not
Specified Total
Parcels 4,938 390 1,323 4,908 3,880 152439
Percentage 32.0% 2.5% 8.6% 31.8% 25.1% 100%
Land Use as of 2000
Single
Familv Other
Residential Non-Residential Vacant/
Unclassified
Total
Parcels 11,179 1,082 983 2,195 15,439
Percents e 72.4% 7.0% 6.4% 14.2% 100%
* Entire watershed, including all tributaries
Existing sanitary sewer trunk lines, completed in the mid 1980's, are installed along the entire
length of FEMA-regulated portions of McDowell Creek and its tributaries. Currently, no
additional capital sewer improvements are planned along the creek based on the Charlotte-
Mecklenburg Utility Department 2002 Capital Improvement Plan (CIP). A greenway trail is
planned along the creek, which will be explained in more detail later. Development of such trails
is announced for public information similar to the example shown in Figure 13.
UcDoaell Creek Watershed Preliminary Engineering Report I I
Fig. 12 At Leisure Lane
A review of the capital improvement plans (CIP) was completed for various City and County
agencies including the following:
?? City and County Storm Water Services
?? Neighborhood Development
?? Charlotte Department of Transportation
?? Mecklenburg County Park and Recreation
?? Charlotte-Mecklenburg Planning Commission
Currently, the only planned CIP in the McDowell Creek basin includes the creation of three
greenway trails (See Fig. 13) consisting of:
1. Approximately 2.4 miles along Torrence Creek from Bradford Hill Lane towards
upstream
2. Approximately 2.7 miles along Torrence Creek Trib 1, from its confluence with Torrence
Creek towards upstream
3. Approximately 3.6 miles along McDowell Creek from Bradford Hill Lane towards
downstream.
McDoHell Creek Watershed Preliminary Engineering Report 12
Fig. 13 Example of Proposed Greenway Trail
The general locations of these trails and their proximity to the potentially flooded structures
within the basin are shown in Figure 14. The full length of some of the proposed greenway trails
extend beyond the limits of Figure 14, and have been eliminated so that the potentially flooded
areas can be shown in as much detail as possible.
Of the above list, approximately 0.7 mile of item 1, from Bradford Hill Lane to McCoy Road has
been completed, and another 0.6 mile from Bradford Hill Lane to the confluence with McDowell
Creek is under construction. The remaining trails have been proposed for future construction.
The construction of these greenway trails is not expected to alter the drainage and flooding
patterns in the watershed and the flood mitigation analyses of this report will be valid unless
other major alterations are planned for the watershed due to newly planned CIP's.
A condensed view and lists of the capital improvement projects for Mecklenburg County are
shown in Figure 15.

Fig. 14 Greenway Trails and their Relationships to Potential Flood Areas
%IcDo"eII Creek Watershed Preliminary Engineering Repon 13
INTER-AGENCY COORDINATION -cltycountyNanning CommissWn
MAP OF CAPITAL PROJECTS
MECKLENBURG COUNTY = = _
tEGEND
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Catawba River
h.gamrnood w,rlapn,..t --
Basin
Coto*ba
wxrEH
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Fig. 15 Summary of City-County Capital Improvement Projects, 1999
McDowell Creek Watershed Preliminary Engineering Report 14
1.3 Aquatic Habitat and Environmental Monitoring
The McDowell Creek watershed drains in a westerly direction into the Catawba River between
the Cowins Ford Dam that forms Lake Norman (Charlotte drinking water supply) and the upper
reaches of Mountain Island Lake (Charlotte's primary drinking water supply). This location on
the Catawba River is also vital for Charlotte's neighbors to the west, as the cities of Gastonia and
Mount Holly also have water supply intakes near the mouth of the McDowell Creek. This
watershed is actively being studied by various groups. Active studies at this time include:
?? Mecklenburg County Storm Water Services (MCSWS) and Watershed Concepts (this
report)
?? Local Watershed Management Plan (NC Wetlands Restoration Program and CH2M-Hill)
?? Water Quality Computer Model Simulation (MCDEP and TetraTech)
?? McDowell Creek Watershed Smart Growth for Clean Water Partnership (NALGEP,
Charlotte, Mecklenburg County, Cornelius, Huntersville, Trust for Public Lands)
It is important to note that while various initiatives are underway, each has a different objective.
Yet as each initiative progresses, the participants are communicating and coordinating their
efforts and sharing information. Parallel with these studies, CMUD is performing wastewater
master planning for the watershed to make sure that the availability of sewer capacity does not
impact future watershed growth. As of the date of this report, none of these initiatives has final
reports to supplement the information presented.
There are various land acquisition programs underway to protect and buffer the watershed from
non-point source pollutants and development, including the Trust for Public Lands and the
Mecklenburg County Park and Recreation Department. Together, through the Mountain Island
Lake Initiative, each is purchasing large tracts of land to be preserved as open space.
Primary pollutants from land development activities include nutrients (phosphorus and nitrogen
from fertilizers), fecal coliform (animal waste and sanitary sewer overflows) and sediment (bank
erosion and construction activities). The Mountain Island Lake Marine Commission has already
noted the introduction of Hydrilla (Hydrilla L.C. Rich), an extremely aggressive, invasive
aquatic plant that chokes the oxygen from a «ater body and directly impacts water quality. A
Hydrilla-eating carp has been introduced to combat the problem. However, the direct cause of
the problem stems from the abundance of nutrients that fertilize this plant, flowing downstream
through the McDowell Creek watershed.
During the site visit to McDowell Creek in May 2001, fish of 45 inches long and frogs of
various sizes were observed in a few sites. In addition, other signs of riparian wildlife were
present along the stream. These included the teeth marks of beavers, footprints of small hoofed
animals, and mammalian droppings. These observations point to the existence of a number of
animals along the creek. The list would include varieties of reptiles, rodents, small mammals,
birds, insects and other species that thrive in this environment. The dense vegetative growth
along the creek was found to be heavily infested with ticks, suggesting that there is sufficient
warm-blooded animal life for the survival and proliferation of the ticks.
McDoweII Creek Watershed Preliminary Engineering Report 15
Mecklenburg County Department of Environmental Protection (MCDEP) maintains several
monitoring stations along McDowell Creek and its tributaries. A summary of the collected water
quality data is shown in Table 2. While the Macroinvertebrate Taxa Richness sampling and the
Fish Bioassesment sampling do include Poor and Fair ratings since 1994, the overall Water
Quality Index has consistently ranked as Average, Good and Good-Excellent. The overall water
quality has generally remained consistent in the watershed since 1996. One flow monitoring
station, USGS Gage 0214266000, has been in operation since November 1996 at the MC3 site,
located at McDowell Creek and Beatties Ford Road crossing.
Table 2. MCDEP. Water Quality Monitoring Summary
NC Piedmont
Macroinvertebrate Taxa Jul-94 Sep-97 Jun-98 May-99 Jul-00
Richness

Site
Location
SEPT n?
at
SEPT
at
in
SEPT
SEPT n?
at
i
SEPT nn
R
inng R
ng
i Rating R
t
ng Rating
MC4 McDowell Cr @ 14 Good/Fair 8 Fair 5 Poor 8 Fair 7 Fair
Beatties Ford Rd
MC2A McDowell Cr @ 5 Poor 8 Fair
Sam Furr Rd
MC2A1 McDowell Cr @ 8 Fair 6 Poor 6 Poor 7 Fair 6 Fair
Gilead Rd
MOE Torrence Cr @
Bradford Hill Rd 12 Fair 12 Fair 7 Fair 10 Fair 7 Fair
Fish Bioassessment May-96
Site Location NCIB I WQ Rating
MC4 McDowell Cr (a, Beatties Ford Rd 42 Fair
MC4A McDowell Cr (a, Neck Rd 46 Fair/Good
MC2A McDowell Cr @ Sam Fun Rd 46 Fair/Good
MC2A1 McDowell Cr , Gilead Rd 46 Fair/Good
MOE Torrence Cr (a, Bradford Hill Rd 46 Fair/Good
Water Quality Index May-96 May-97 M ay-98 Jun-99 May-00

Site
Location
WQI
R
nl
WQI
R
Q
l
WQI
2 t
Q
l
WQ1 WQI
g
at ati
ng 1
i
ng Rating
n
MC4 McDowell Cr @ 71 Good 73 Good 70 Good 74 Good 76 Good
Baetties Ford Rd /Exc.
MC4A McDowell Cr @ 62 Average 66 Good 69 Average 70 Good 77 Good
Neck Rd /Exc.
MC2A1 McDowell Cr @ 72 Good 77 Good/Exc. 75 Good/Exc 80 Excellent - -
Gilead Rd .
MOE Torrence Cr @ 73 Good 79 Good/Exc. 71 Good 71 Good 71 Good
Bradford Hill Ln
McDowell Creek Watershed Preliminary Engineering Report 16
1.4 Rosgen Applied River Morpho logy Assessment
The Rosgen stream classification system was utilized to provide an initial assessment of the
morphology of McDowell Creek. The Rosgen system uses field measurements of stream
features to describe a stream by morphologic type. An array of stream types is presented under
the system that is delineated by slope, channel materials, width/depth ratio, sinuosity and
entrenchment ratio. For the assessment of McDowell Creek, the stream type is described at the
geomorphic characterization level (Level I) of the hierarchical system of classification. At this
level of inventory, the channel pattern, shape and slope are described (Rosgen, 1996).
Information utilized as a part of this classification included field observations, aerial
photography, USGS quadrangle maps, and other digital topographic information for
investigation of the channel pattern and valley form.
The data for Rosgen classification of McDowell Creek is summarized in Table 3. The low
sinuosity of the channel is primarily due to the installation of the sewage main line and straight
alignment of the stream in many reaches. Generally, the channel displays a low width/depth
ratio, low sinuosity and relatively low channel slope. However, after careful examination of the
tendencies within the creek, the majority of McDowell Creek was classified as a type G channel
with some reaches possibly being classified as type F. Indicators of a new bankful flow line
were observed below the historic top-of-bank, which imply that the channel has incised within
the historic floodplain. This has most likely resulted from a combination of urbanization of the
watershed and manual re-grading of the channel. The historic floodplain, which was formed as
an alluvial plain bounded by gentle slopes of upland soils, currently forms a terrace that confines
the channel.
Table 3. Rosgen Level I
Classification Parameters
McDowell Creek
Channel Length 48,714 ft
Downstream Invert 641.49 ft
Upstream Invert 724.18 fl
Channel Slope 0.17%
Valley Length 48,405 ft
Sinuosity 1.01
Average Bankful Depth 5 ft
The channel bank slopes are relatively steep
with the slopes ranging from 1:1 to vertical.
Despite these steep slopes, the banks appear to
be fairly stable. The cohesive bank material and
dense riparian vegetation act to stabilize the
banks and resist erosive forces. In some
locations, riprap has been placed along the toe of
the banks to provide additional stability. Along
reaches where riprap is not present and the bank
material is less cohesive, channel widening
processes are evident. This channel widening is
resulting in an evolutionary transition to a type F channel. There are occasional reaches where
the channel has developed sufficient belt width to begin to form a meandering pattern with stable
point bars as shown in Figures 4 and 5.
The channel profile appears to be relatively stable and not subject to excessive degradation or
aggradation. There is evidence, however, of a significant sediment load that is being transported
by the stream. Depositional features such as mid-channel bars, side bars and embryonic point
bars are evident along many reaches of the stream. It is likely that the primary source of this
depositional material is from construction activities within the watershed and that this material is
being transported though the stream system without significant aggradation of the channel bed.
McDoweIICreek Watershed PreIiminaryEngineeringReport 17
1.5 Bank Stability Problem Identification
As described before, the stream and its tributaries have a wide densely vegetated floodplain. The
floodplain and the channel itself are stabilized against severe floods and serious erosion. The
main floodway channel and the adjoining floodplain seem to be in a stable state.
Moderate to low deposition of sediments was observed in a field visit to McDowell Creek on
May 2, 2001. The flat creek slopes do not provide sufficient grade for the flow to carry large
suspended or bed sediment loads. Occasionally, there would be point or middle bars on the
stream as shown in Figures 3 and 4. This is an indication of good vegetative cover along the
stream, relatively stable channel, and low erosion of the banks. In general, bank instability does
not seem to be a major problem along McDowell Creek.
McDowell Creek Watershed Preliminary Engineering Report 18
2. BENEFIT:COST ECONOMIC ANALYSIS
2.1 Riverine Flood Model Overview
FEMA's Riverine Flood Model (Version 1. 11, February 1996) was utilized to perform flood
damage and benefit:cost analysis. This model is based on Quattro-Pro spreadsheet and its results
are consistent with Mecklenburg County's previous analyses that used the same program. In this
model, built-in probability based damages are calculated for a structure given the finished floor
elevation of that structure. The model calculates benefits (damages avoided by undertaking a
certain mitigation measure) vs. the estimated cost of that particular mitigation measure.
There are no structures in the McDowell Creek watershed with finished floor elevations
below the BFE. Structures analyzed for potential flood damage are limited to those with
finished floor elevations in the flood fringe areas. The benefit:cost model estimates damages on
the basis of the 10-, 50-, 100- and 500-year floods and hence calculates damages for structures
with finished floor elevations above the current BFE. The flood elevation were determined
using the US Army Corps of Engineers model HEC-RAS (Version 2.2, March 1999). The future
100-year flood elevations were based on the County's projected land use estimates for the year
2020.
The benefit:cost model utilizes two levels of data input; a level 1 with minimal data requirements
(using default values) and a level 2, with detailed data regarding a structure type, use,
replacement value, contents value, and relocation costs. For the purposes of this study, level 2
analysis was adopted for two reasons: 1) this level of analysis produces more realistic damage
estimate information, and 2) the analyses are consistent with the County's previous benefit:cost
analyses. The program uses the input flood elevations and flows to determine a probabilistic
estimate of the damages to the structure based on the finished floor elevation of the structure.
The probabilistic tables are built into the program and are not altered by the user.
2.2 Economic Data
To perform the level 2 benefit:cost analysis, the model utilizes several attributes and values for
each structure. This type of information was gathered for each affected structure from the GIS
data at the Mecklenburg County website. Information provided to the model included:
Building T}pe: Structures are categorized as single story without basement, two-story with
basement, etc. The structure type is used by the model for selecting the
specific built-in lookup table for flood depth vs. damage as percent of the
structure value.
Building Value: The building values as given in the Mecklenburg County GIS website were
multiplied by 1.25 to reflect the building values in 2001 dollars. These values
were used as the replacement values for the affected structures.
Content Value: The content value of each structure was assumed to be 25% of the current
(2001) replacement value of the structure. This assumption is consistent with
previous benefit:cost analyses of Mecklenburg County.
%1cDoHell Creek Watershed Preliminary Engineering Report 19
Floor Elevation: For each affected structure, the elevation of the lowest finished floor was
provided to the model. The model uses this parameter as the zero damage
elevation for the structure. The finished floor elevation data were obtained
from the Mecklenburg County GIS data and elevation certificate files,
supplemented by surveys performed by ESP Associates Surveyors.
Relocation Cost: A constant relocation cost per household was used as the basis for economic
analysis. This relocation cost was determined by Mecklenburg County and had
been used in previous bewfit:cost analyses.
The present value of all benefit and cost figures were calculated using a 7.0% discount rate, a 30-
year project life for the elevate and levee mitigation option, and a 100-year project life for the
acquisition option. These assumptions are consistent with the specifications of the Riverine
Flood Model (1996, p. 6-15).
2.3 Hydraulic Data
In order to determine the level of flooding at each structure, the model requires flow and
elevation data to be entered for 10-, 50-, 100-, and 500-year floods. This information already
existed for McDowell Creek from HEC-RAS modeling of the creek performed earlier by
Watershed Concepts. However, HEC-RAS output files list elevations at specific cross sections
along the stream. Therefore, water surface elevations were extrapolated for each individual
structure. To perform this task, a line was manually drawn from each structure to the creek
centerline. The Watershed Concepts WISE program was then utilized to perform the
extrapolation and output of elevations for the different frequency floods for each individual
structure. The flows and their corresponding water surface elevations are the required data for
the model to determine flood damages to each structure.
2.4 Modeling Process
The benefit:cost model includes a series of default depth-damage curves based on nationwide
flood loss information. Specific depth-damage curves for Mecklenburg County were developed
and used for this analysis utilizing flood loss data from the storm event of July 1997. Damages
to each structure are calculated by the model based on the flood depth above the finished floor
elevation of the structure, and the probability (or frequency) of occurrence of that flood in a
given span of time. Damages are annualized for the benefit:cost analysis.
2.5 Economic Analysis
For any mitigation measure considered, the avoided flooding damage is the benefit derived from
that particular mitigation measure. This benefit, when compared to the cost of undertaking the
mitigation measure, constitutes the basis for the benefit:cost analysis. When the ratio of benefit
to cost is greater than 1.0, the measure is deemed feasible, and when the ratio is smaller than 1.0,
the measure is rejected.
The benefit:cost program has built-in data for the costs of acquisition or elevating the structure
for Mecklenburg County. However, for other mitigation measures, the cost was separately
determined and the benefit:cost ratio calculated. Due to the fact that only a few residential
McDowell Creek Watershed Preliminary Engineering Report 20
structures are affected in the McDowell Creek watershed, the only other mitigation measure
considered was the construction of flood levees, as described in the next section of the report.
As suggested by Mecklenburg County Storm Water Services (MCSWS), it was decided fiat
mitigation measures should not be concentrated on individual buildings. Instead, MCSWS
preferred the concept of "mitigation projects," whereby the mitigation measures were considered
for the improvement of a project area or a neighborhood community. On the basis of this
concept, the mitigation measures have been proposed for project areas (or problem
neighborhoods). Four such project areas are identified for the McDowell Creek watershed as
described in the next section of the report.
2.6 Improvements
There are no severe flooding problems in the McDowell Creek watershed. Only four
neighborhoods were identified with flooding potential, as reported in the next section of this
report. Preliminary analyses indicated that only a few structures are involved in the affected
areas, and the least expensive mitigation measures would be the only feasible ones. Therefore
three basic mitigation measures were considered for this watershed: elevating the structure,
acquisition of the property, or construction of flood levees. None of the three measures
provided a benefit:cost ratio higher than 1.0. Therefore, no action is recommended for this
watershed.
McDo"cII Creek Watershed Preliminary Engineering Report 7 1
3. FLOOD HAZARD MITIGATION
3.1 FEMA Regulated Stream Service Requests
There have been 91 Service Requests filed through the City/County Customer Service system
(336-RAIN) hotline in the McDowell Creek watershed. The majority of the service requests
involve channel bank erosion. For each request a severity category has been specified.
However, except for 3 cases, the exact type of the request has not been identified. Instead, only
the severity of the requested service is recorded in the system database. Table 4 summarizes the
flood related service requests by severity in the McDowell Creek watershed. Only one of the
requests is for property that has been identified in this report as having a flood potential (15130
Stonegreen Ln.). A total of 10 of the complaints are for property located immediately adjacent to
the McDowell Creek floodplain. However, except for 15130 Stonegreen Lane, no structures on
the remaining nine parcels have been identified as being in the flood fringe areas.
Table 4. Service Requests in McDowell Creek Watershed
Severity of Service Requested Frequency No. in Potential Flood Zonez No. in B:C Analysis3
A 4 0 0
B 20 0 0
C 67 1 1
I A to C: Most to least severe; categorized by the Charlotte-Mecklenburg Storm Water Services
2 Lots with structures whose footprints intersected with the flood boundaries
3 Lots with structures that were analyzed for benefit:cost ratio for mitigation measures
3.2 Repetitive Loss Structures
According to information provided by Mecklenburg County Storm Water Services, no reports of
repetitive losses exist within the McDowell Creek watershed.
3.3 Permanent Storm Water Easements
There are no permanent Storm Water Easements in the McDowell Creek watershed that provide
access to the creek or its tributaries.
3.4 Roadway Overtopping Problem Locations
From HEC-RAS modeling results of McDowell Creek watershed, roadway overtopping
locations were investigated based on the existing and future 100-year flood conditions. Table 5
summarizes the roadway overtopping problem locations for the study streams and tributaries.
Locations of the overtopping roads are shown in Figure 16. Several conclusions and
recommendations can be derived from Table 5:
1. Considering the fact that a flow depth of 24 inches (2 ft) can sweep away a moving vehicle,
there will be several problem locations in case of a 100-year flood. The most prominent of
these is McIlwaine Road. The crossing will be in 3.2 and 6.3 ft of water, respectively, for the
existing and future 100-year floods. However, this is due to a backwater effect from
McDow ell Creek Watershed Preliminary Engineering Report 22
McDowell Creek, not a high-velocity floodwater of equivalent depth. Among measures to
mitigate this hazard are warning signs for approaching motorists and consideration for raising
the elevation of the stream crossing as a future CIP for the Huntersville DOT. Other problem
spots for large depths of water are on private crossings, identified as a farm bridge and a foot
bridge, which should be abandoned in case of a flood. All other problem areas listed in Table
5 would require warning signs to alert motorists to avoid the crossing in case of a flood.
2. Flood hazards at road crossings could be minimized by assuring that culverts and bridges
along the entire stream system have the maximum capacity to pass the flood flows. Regular
inspection and maintenance schedules should be established at all stream crossings to assure
that sediment and other debris such as fallen trees or urban trash do not collect at the
upstream face of the culverts and bridges, compromising their flow capacity.
3. Guardrails (or other indicators) should be provided at all problem sites such that drivers could
be guided away from the edge of the road in case of a flood. The protection should be
adequate so that if a vehicle is stranded or swept away, it can be stopped by the guardrail,
preventing the vehicle from entering deeper and fister moving flow regions and allowing for
rescue crews to reach the stranded vehicle.
4. Depth sensors and a relay system could be installed on or near the crossings such that they
would alert emergency response teams to the high water depth and allow them to re-route
traffic or prepare for emergencies at the site.
Table 5. Roadway Overtopping Problem Locations

Stream/Road Crossing
Structure
Type Culvert Size
No. @ Size
(ft) Top of Road
Elevation
(ft NAVD) 100-Yr Flood
Elevation
Existing
(ft NAVD) Flood Depth
Existing
(ft) 100-Yr Floo
Elevation
Future
(ft NAVD) F1ood.Depth
Future
(ft)
McDowell Creek
Sam Furr Road Bridge 701.3 700.5 - 702.3 1.0

Torrence Creek
Farm Bridge Bridge 669.5 673.7 4.2 674.8 5.3

Torr. Cr, Trib 1
Foot Bridge Bridge 669.3 673.2* 3.9 674.1 * 4.8
Gilead Road Culvert 2 8 X7.5 679.5 679.5 - 680.0 0.5
Stumptown Road Culvert 2@6 Cir 705.8 706.5 0.7 707.0 1.2

McDowell Cr Trib 1
Mcllwaine Road Bridge 661.8 665.0** 3.2 668.1 ** 6.3

Caldwell Station
Creek
Statesville Road Culvert 3@8X7 Box 718.7 717.0 - 718.9 0.2

- csacKwaier rrom i orrence t_reeK
** Backwater from McDowell Creek
%IcDoN ell Creek Watershed Preliminary Engineering Report 23
Three flood mitigation measures were recognized as the only viable options for the structures
that are in the flood fringe areas (within two feet of the BFE) in the McDowell Creek watershed.
These measures were acquisition, elevating the finished floor of the structure two feet above the
BFE, or construction of a berm or dike to contain the floodwater. The benefit:cost analysis for
the four project areas, shown in Figures E2 and E3, were performed using the standard methods
described in FEMA's Manual 259, Engineering Principles and Practices for Retrofitting Flood
Prone Residential Buildings (FEMA, January 1995), and the Riverine Flood model (Version
1. 11, February 10, 1996) developed by FEMA. Details of the analysis will be presented later.
The summary of the benefit:cost analysis is shown in Table 6. The benefit and cost values in this
table are the present values of the annual benefits and costs of each mitigation option. The low
benefit:cost ratios of these neighborhoods and structures is indicative of the fact that all of the
structures have finished floor elevations above the BFE. None of the structures would actually
experience inundation in case of a 100-year flood. The small amount of damages calculated by
the benefit:cost program for these structures results from the statistical probability of occurrence
of a 500-year flood.
McDowell Creek Watershed Preliminary Engineering Repon 24

3.5 Flood Mitigation Improvement Analysis

Also included in Table 6 are the highest benefit:cost ratios for individual structures to provide a
means of judging the range of variation. B,-cause only benefit:cost ratios greater than 1.0 were
considered economically feasible, it is clear from these figures that no mitigation measure is
going to be economically justified, either for an entire project area or for individual structures.
Table 6. Summary of the Benefit:Cost Analysis for the Four Mitigation Project Areas
Mitigation Options*
Acquisition Elevation Levee
No. of
Structures Project Neighborhood/Area Benefit Cost B:C Benefit Cost B:C Benefit Cost B:C
9 Henderson Park Rd/Leis ure
Ln/Lullwatcr Cv 54,016 1,597,405 0.03 26,615 407,750 0.07 42,858 265,672 0.2
Highest
individual 7641 Henderson Park 8,450 146,479 0.06 4,349 35,867 0.12 - - -

2 Gilead Rd 3,855 196,051 0.02 2,210 69,460 0.03 3,212 112,001 0.03
Highest
individual 8010 Gilead Rd 2,745 107,056 0,03 1,623 45,410 0.04 -- - -

3 Cumbria Ct/Stonegrccn Ln 24,821 998,853 0.03 17,267 226,768 0.08 21,201 50,507 0.42
Highest
individual 15129 Stonegreen Ln 13,652 347,509 0.04 10,077 82,508 0.12 - - -

1 Delancey Ln 32,310 344,039 0.09 10,526 74,423 0.14 18,816 44,216 0.43
Highest
individual 15701 Delancey Ln 32,310 344,039 0.09 10,526 74,423 0.14 18,816 44,216 0.43

,tienctlts and costs are to dollars
Compared to other basins within Mecklenburg County, the McDowell Creek watershed is in a
younger state of development and does not suffer from severe flooding problems. Based on the
latest County elevation certificate data and survey results, a total of 15 structures would be
within the fringe of the ECF or the FCF. Table 7 shows the flooding statistics for these
structures, all of which are residential and post-FIRM (built after 1981). The flooded homes can
be grouped into four project areas, listed in Table 7. The four groups have been treated
separately in Table 7 and in applying mitigation measures so that individual benefit:cost analyses
could be performed for each project area.
Table 7. Structures Within Existing 100-year Floodplain
No. of
Structures Project Neighborhood/Area No.
Floode No. within
2ft of BITE Avg. Flood
Depth* Median
Depth* Highest
Depth* Lowest
Depth*

9 Henderson Park Rd/Leisure Ln/Lullwater Cv 0 9 -0.87 -1.30 -0.11 -1.63

2 Gilead Road 0 2 -1.39 -1.39 -0.86 -1.91

3 Cumbria Ct/Stoneerecn Ln 0 3 -0.43 -0.63 -0.08 -0.78

1 Delancey Ln 0 1 -0.01 -0.01 -0.01 -0.01

Negative numbers indicate that the finished floor elevation is above the IUU-yr flood elevation; depths are in feet.
McDowell Creek Watershed Preliminary Engineering Report 25
Alternative Evaluation
Within the McDowell Creek watershed there are a total of 15 structures, which are in the flood
fringe areas (within 2 ft of BFE). These structures have been clustered into four project areas as
shown in Table 7. A total of four alternatives were analyzed for these project areas. Additional
alternatives were considered, but ruled out as economically infeasible after preliminary analyses.
Alternative 1- Acquisition
In this alternative, the structure in danger of flooding is purchased and removed. FEMA
regulations specify this alternative to be adopted if the benefit:cost ratio equals or exceeds 1.0.
Calculations for determining the cost of this alternative are programmed into the benefit:cost
program as described in Section 2 of this report. A return rate of 7% and project life of 100
years were used for this alternative. As indicated in Table 7, none of the project areas or
individual structures meets this requirement and hence this alternative is not feasible.
Alternative 2 - Elevation
This alternative involves elevating the potentially flooded structure 2 ft above the BFE. The
costs of elevating structures in Mecklenburg County are programmed in the benefit:cost program
as well. The adoption criteria for this alternative is also a benefit:cost ratio of 1.0 or higher.
Table 7 shows that none of the project areas or individual structures meets the limiting criteria of
this alternative, and hence this alternative is abandoned as well.
Alternative 3 - Flood Barrier
In this alternative, the cost of the construction of an earthen levee as a flood barrier is considered.
The levee is designed with a 3-ft freeboard, i.e., the elevation of the top of the levee is placed at 3
ft above the BFE. By its nature, this alternative is better suited to project areas or a cluster of
structures than for individual units. Calculations for the cost of a levee are carried out outside
the benefit:cost program, and involve estimations of material needed, haul distances, placement,
and equipment mobilization and demobilization. Results of the calculations are summarized in
Table 7 and indicate that this alternative is also too expensive and should be abandoned.
Alternative 4 -No Action
This is the default alternative, when the benefit:cost analysis shows that adopting any of the other
mitigation measures results in more costs than benefits. After elimination of the other
alternatives as described above, this alternative is the only acceptable one for the McDowell
Creek watershed.
Although the No-Action alternative is the only feasible one recommended for McDowell Creek,
results of the benefit:cost analysis for the individual project areas are summarized below.
McDo" ell Creek Watershed Preliminary Engineering Report 26
Henderson Park/Leisure/Lullrvater Neighborhood
The summary of the benefit:cost analysis for the Henderson Park Road, Leisure Lane and
Lullwater Cove neighborhood is shown in Table 8. The general neighborhood is shown in
Figure 17. A total of 9 structures in this neighborhood are in flood fringe areas. The highest
benefit:cost ratio for any of the mitigation measures for the neighborhood is 0.161 for the levee
(flood barrier) alternative, well below the acceptable level of 1.0 for adoption of the mitigation
measure. The highest benefit:cost ratio for an individual structure in this neighborhood is 0.12
for the elevation option for 7641 Henderson Park. The levees in this neighborhood are used for a
cluster of houses, and hence individual costs for this option cannot be used for comparison of
structures.
Table 8. Mitigation Measures for Henderson Park/Leisure/Lullwater Neighborhood
Possible Mitigation Project
Acquisition Elevation Levee
Benefit Cost Ratio Benefit Cost Ratio Benefit Cost Ratio

$54,016 $ 1,597,405 0.034 $ 26,615 $ 407,750 0.065 $ 42,858 $ 265,672 0.161

r : r,
Fig. 17 Houses with Flooding Potential in Henderson Park/Lc isure/Lullwater Neighborhood

McDowell Creek Watershed Preliminary Engineering Report 27
Gilead Neighborhood
The summary of the benefit:cost analysis for the Gilead Road neighborhood is shown in Table 9.
The general neighborhood is shown in Figure 18. Two structures in this neighborhood are in
flood fringe areas. The highest benefit:cost ratio for any of the mitigation measures for the
neighborhood is 0.03, well below the acceptable level of 1.0 for adoption of the mitigation
measure. The low benefit:cost ratio indicates that the finished floor elevations of these houses
are above the BFE, and the small benefit figures result from the low probability of flooding in
case of a 500-year flood. The highest benefit:cost ratio for an individual structure in this
neighborhood is 0.04, still well below the feasible level of 1.0.
Table 9. Mitigation Measures for Gilead Neighborhood
Possible Mitigation Project
Acquisition Elevation Levee
Benefit Cost Ratio Benefit Cost Ratio Benefit Cost Ratio

$ 3,855 $ 196,051 0.020 $ 2,210 $ 69,460 0.032 $ 3,212 $ 112,001 0.029

McDowell Creek Watershed Preliminary Engineering Report 28
Cumbria/Stonegreen Neighborhood
The summary of the benefit:cost analysis for the Cumbria Ct and Stonegreen Ln neighborhood
is shown in Table 10. The general neighborhood is shown in Figure 19. Three structures in this
neighborhood are in flood fringe areas. The highest benefit:cost ratio is 0.42 for the levee
alternative, decidedly below the acceptable level of 1.0 for feasibility of the mitigation measure.
The highest benefit:cost ratio for an individual structure in this neighborhood is 0.12, still well
below the feasible level of 1.0.
Table 10. Mitigation Measures for Cumbria/Stone reen Neighborhood
Possible Mitigation Project
Acquisition Elevation Levee
Benefit Cost Ratio Benefit Cost Ratio Benefit Cost Ratio

S 24,821 S 998,853 0.025 S 17,267 S 226.768 0.076 S 21,201 S 50.507 0.420

L_

Fig. 19 Houses with Flooding Potential in Cumbria/Stonegrcen Neighborhood

AX 11
L ?.
? j
T?i 'T 3
ar r?
,RY y2fri a? ??

McDowell Creek Watershed Preliminary Engineering Report 29
Delancey Neighborhood
The summary of the benefit:cost analysis for the Delancey Lane neighborhood is shown in Table
11. The general neighborhood is shown in Figure 20. A single structure in this neighborhood is
in flood fringe area. The highest benefit:cost ratio of any of the mitigation measures considered
is 0.43 for the levee (flood barrier) alternative, which is below the acceptable level of 1.0 for the
alternative to be economically feasible. This benefit:cost ratio of 0.43 is also the highest
individual value since only one house is affected in this area. The levee option is included in the
analysis for this neighborhood since the levee would be constructed fir the protection of this
structure only, and all the costs can be attributed to this single structure.
Table 11. Mitigation Measures for Delancey Neighborhood
Possible Mitigation Project
Ac uisition Elevation Levee
Benefit Cost Ratio Benefit Cost Ratio Benefit Cost Ratio
$ 32,310 $ 344,039 0.09 $ 10,526 $ 74,423 0.14 $ 18,816 $ 44,216 0.43

1 71
"L L
fl '

I - -l

Fig. 20 House with Flooding Potential in Delancey Neighborhood
McDowell Creek Watershed Preliminary Engineering Report 30
4. CONCLUSIONS AND RECOMMENDATIONS
The McDowell Creek basin constitutes a young but fast developing section of Mecklenburg
County. McDowell Creek and its main tributaries, McDowell Trib.1, Caldwell Station, Torrence
Creek, and Torrence Creek Tribs. 1 and 2 are all in a reasonably stable condition due to four
main factors:
1. Stream banks stabilized by riprap or other means to safeguard a sewer main line that
extends along the creek
2. Heavily vegetated banks and floodplains
3. Numerous road crossings and other man-made structures that form grade controls and
limit bank erosion or stream scour
4. Past stabilization efforts along McDowell Creek and its tributaries
In the event of a 100-year flood, flooding hazard for the structures lining the banks of the creek
may be identified in four general neighborhoods. A total of 15 structures are affected, all of
which are located in the flood fringe areas (within 2 ft of BFE). Flood inundation damages are
nonexistent. Of the three mitigation measures considered for these two neighborhoods, namely
elevating the structures, berm construction, and acquisition, none proved to be economically
justifiable. No flood mitigation measures are recommended for this watershed.
There are several road crossings that are subject to overtopping in case of a 100-year flood.
Flood depths over the roadway may be as high as 6.3 ft in one case for the future 100-year flood
(backwater effect). Two smaller crossings on non-public roads would also be flooded severely.
Several mitigation measures should be considered for the road crossings of this watershed, which
include warning signs for the approaching motorists, tall guardrails or indicators to guide the
vehicles away from the edge of the road in case of a flash flood, raising the elevation of road at
the stream crossing, and emergency response team notification. Regular maintenance at man-
made structures such as road crossings and storm water outfalls will be necessary to maintain the
stream capacity and stability.
McDo%ell Creek Watershed Preliminary Engineering Report 31
5. REFERENCES
The following sources have been consulted in the preparation of this report:
Rosgen, D. 1996. Applied River Morphology, Wildland Hydrology, Pagosa Springs, CO.
Federal Emergency Management Agency 1995. Engineering Principles and Practices for
Retrofitting Flood Prone Residential Buildings, Manual 259, FEMA Mitigation
Directorate, January.
Federal Emergency Management Agency 1996. Benefit-Cost Program, Riverine Flood Module,
Version 1. 11, Revised February 10 (software distributed by FEMA).
R.S. Means 2000. Site Work and Landscape Cost Data, 20`h Annual Edition, Construction
Publishers & Consultants, Kingston, MA 02364-0800
County of Mecklenburg, North Carolina Website, www. co.mecklenburg.nc.us/.
McDowell Creek Watershed Preliminary Engineering Report 32
APPENDIX D

800 52, 000' W 80°51.000' W WGS84
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80052,600, W 80051.000' 1 GS84
MN TN - .? 1 MILE
7Q 1000 FEET 0 504 1000 METERS
Printed from TOPO1 02001 National Geographic Holdings (www.topo.com)
and NCEEP Stream Restoration Project: Figure D1. Reference Reach Sites, Un-named
Tributaries to Reeds Creek Cove, Lake Norman, March 2004
H•k .'. ".".'...
I ?t Caldwell Station Ck., Mecklenburg, CO., NC J
PRS M ?. Iredell Co. N.C.

693.106 ft

R 28.968
Meander Belt Widtn
76.179 ft
Riffle /
Pool 1
R 23.614
z -+_

® R 30.086
R 27.974
?? : ? R 97.981
10 Meander Radius
of Curvature
1% R 27.403 R 36.312
R 43.681
R 76.742
R 54.135 -
Feet
0 25 50 100 200 400
NCEFP Caldwell Statm Creek I Figure D2. West Fork Reeds Creek Reference Reach Planview 109 2V =-"-Ik Restoration Site, Mecklenburg Co., NC

•
•

East Reeds Cove CS Reference Reach X-Section # 1 (Meander) West
103
101
95
93
0
20 4U 60 60 10
Bankfull Width • 21.0 ft Bankfull Max Depth • 5.1 ft Floodprone Width >100 ft 11
0
Bankfull Area • 63.7 sq. R Bankfull Avg. Depth • 3.0 ft Entrenchment Ratio >4.8
W/o • 6.9
Ea st Reeds Cove CS Reference Reach X-Section At 2 (Inflection) We st
103
101
C 99
O
a 97
W
lL 95
93
0
20 40 60 BO 10
0
Bankfull Width • 20.9 ft Bankfull Max Depth • 4.7 ft Floodprone Width >100 ft 11
Bankfull Area • 62.5 sq. ft Bankfull Avg. Depth • 3.0 ft Entrenchment Ratio >4.8
WID • 7.0
Ea st Reeds Cove CS Reference Reach X-Section # 3 (Meander) We st
103
101
C 99
O
M 97
W
W 95
93 p 20 40 60 60 10
Bankfull Width • 27.2 ft aankfull Max Depth . 5.5 ft Floodprone Width>100 ft n 0
Bankfull Area • 71.5 sq. ft Bankfull Avg. Depth • 2.6 R Entrenchment Ratio >3.7
WID • 10.3
E
1 ast Reeds Cove CS Reference Reach X-Section # 4 (Inflection) We st
03
tOt
C 99
a
97
w
W 95
9
3
0 20 40 BO 80 10
Bankfull Width • 21.2 ft Bankfull Max Depth • 4.7 It Floodprone Width >100 ft n
0
Bankfull Area • 69.8 sq. ft Bankfull Avg. Depth • 3.3 ft Entrenchment Ratio >4.7
WID • 6.4
E
3 ast Reeds Cove CS Reference Reach X-Section # 5 (Meander) We st
10
? 101
O 99
j 97
d
W 95
93
0 20 40 BO BO 100
Bankfull Width • 14.6 ft Bankfull Max Depth • 4.3 ft Floodprone Width >100 ft n
Bankfull Area • 43.6 sq. ft Bankfull Avg. Depth • 2.9 fl Entrenchment Ratio >6.8
WID • 5.0
East Reeds Cove CS Reference Reach X-Section # 6 (Inflection) West
?V3
? 101
00 99
a
j 97
N
_
93
0 20 40 60
Bankfull Width • 16.7 ft Bankfull Max Depth • 5.3 ft Floodprone Width >60 ft n
Bankfull Area • 60.1 sq. ft Bankfull Avg. Depth • 3.6 ft Entrenchment Ratio >6.0
WID • 4.6
NCEEP Caldwell St. Creek Figure D3r Cross Sections
Mar. 2004
Restoration Site - Mecklenburg Co., NC West Fork Reeds Creek Reference Reach • Iredell Co., NC
•
•
•
•
•

95
94
0
m
a?
W 93
92
8
Riffle Areas Pool Areas
NCEEP Caldwell Station Creek Figure D4. West Fork Reeds Creek Reference Reach Longitudinal Profile (A/M
aw ?r_:A Restoration Site, Mecklenburg Co., NC
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Reed's Creek West Fork Meander X-Section I (Fore) and Inflection X-Section 2 (Back)
looking upsteam
Reed's Creek West Fork Meander X-Section 3 (Fore) and Inflection X-Section 4 (Back)
looking upsteam
-2-
Reed's Creek West Fork Meander X-Section 5 looking downsteam
Reed's Creek West Fork Inflection X-Section 6 looking upsteam
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Reed's Creek West Fork Riffle Point A at approximately 233 feet on the Longitudinal
Reed's Creek West Fork Riffle Point B at approximately 545 feet on the Longitudinal
-8-
Reed's Creek West Fork Riffle Point C 15 feet beyond the Longitudinal Profile