MITIGATION PLAN FOR ROWELL BRANCH

COMPENSATORY MITIGATION
PLAN FOR THE ROWEL BRANCH TRACT
For Wetland Impacts Associated with
the Proposed Wilmington Bypass
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Prepared for:
ECOBANK
4007 Clarendon Blvd.
New Bern, North Carolina
1555 Howell Branch Road
Winter Park, Florida
and
The North Carolina Department of Transportation
Raleigh, North Carolina
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Prepared by:
Land Management Group, Inc.
Wilmington, North Carolina
July 23, 1999
Job # 01-98-586
TABLE OF CONTENTS
LIST OF FIGURES .................................................... iii
LIST OF TABLES ....................................................iv
INTRODUCTION ..................................................... 5
SITE DESCRIPTION .................................................. 6
PRIOR ANTHROPOGENIC IMPACTS ................................ 6
PRIOR NATURAL IMPACTS ....................................... 7
1 SOILS ........................................................ 7
VEGETATION .................................................. 7
MITIGATION ......................................................... 7
HYDROLOGICAL RESTORATION .................................. 8
VEGETATION RESTORATION ..................................... 8
j MITIGATION RATIOS AND OFFSET AREAS .......................... 8
MONITORING PLAN .................................................. 9
HYDROLOGICAL MONITORING ................................... 9
VEGETATION MONITORING ...................................... 9
FINAL PROPERTY DISPENSATION ..................................... 10
SUMMARY ......................................................... 10
FIGURES AND TABLES ....................:........... 12
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LIST OF FIGURES
Figure 1. Vicinity map of the Rowel Branch Tract . .......................... 13
Figure 2. The Rowel Branch Tract ....................................... 14
Figure 3. 1973 aerial photo of the Rowel Branch Tract . ...................... 15
Figure 4. 1983 aerial photo of the Rowel Branch Tract . ...................... 16
Figure 5. N.R.C.S. soils map . .......................................... 17
Figure 6. Preliminary overview of construction at the Rowel Branch Tract. ....... 18
Figure 7. Partial topo survey of the Rowel Branch Tract . ..................... 19
Figure 8. Well location map . ........................................... 20
Figure 9. Vegetation transect location map . ............................... 21
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LIST OF TABLES
Table 1. Dominant vegetation in (A) forested riverine and (B) freshwater marsh
mitigation areas . ............................................... 22
Table 2. Mitigation description at the Rowel Branch Tract ..................... 23
Table 3. Planting plan for the Rowel Branch Tract ........................... 24
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INTRODUCTION
ECOBANK (applicant) proposes to restore 16.1 acres of forested riverine
wetland at the Rowel Branch Tract in Brunswick County, North Carolina. The tract will
be used as mitigation for unavoidable wetland impacts associated with the construction
of the proposed Wilmington Bypass by the North Carolina Department of
0 Transportation (NCDOT). NCDOT has contracted with ECOBANK to provide the
wetland mitigation for all Wilmington Bypass wetland impacts.
The tract consists of a riverine/marsh ecosystem which was abandoned and
bypassed when an adjacent water diversion canal was constructed in the 1970s. Two
large areas of the property were also filled to facilitate better tract access during
construction of an adjacent railroad yard.
The applicant proposes to restore the impacted ecosystems by re-routing the
flow of Rowel Branch back into the abandoned ecosystem thus restoring the natural
hydrological regime. This will be accomplished by plugging and back filling the existing
diversion canal. The project will not cause any upstream flooding impacts.
0 The tract will be monitored for five years or until deemed successful. Annual
monitoring reports will be provided to both the Army Corps of Engineers (USACE) and
the North Carolina Division of Water Quality (DWQ). When implemented, the project
will offset a total of 16.1 acres of wetland impacts. Implementation of the project will
occur prior to impacts, thus providing up-front mitigation for the Wilmington Bypass
project.

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SITE DESCRIPTION
The tract is located approximately one mile north of Leland, North Carolina, at
the intersection of the Seaboard Coastline Railroad and Mt. Misery Road (SR 1426) in
an area locally known as Eastbrook (Figure 1). This location is approximately 0.4 miles
south of the proposed Wilmington Bypass.
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PRIOR ANTHROPOGENIC IMPACTS
The Rowel Branch ecosystem was altered between 1973 and 1983 when a
diversion canal approximately 20' wide and 3' deep was installed to facilitate upstream
drainage. The canal (Figure 2) begins at Mt. Misery Road (SR 1426) and extends in an
east-west direction for approximately 2,100 linear feet. At that point it turns
approximately 90° south and runs to the southern end of the property which is
approximately 400 feet south of Eastbrook Drive. The east-west portion of the canal
runs south of the original stream for approximately 800 linear feet. The remaining
portion was excavated directly through the original stream bed and floodplain (Figures
1 3 and 4).
Prior to 1983, extensive fill (approximately three acres) was placed across the
entire floodplain in three places (Figure 2). The fill was apparently excavated from the
diversion canal and used to provide intra-tract access. Upstream, Leland Industrial
Park discharges stormwater into Rowel Branch which eventually flows through this
property.

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PRIOR NATURAL IMPACTS
Past activities by beavers have lengthened the hydroperiod of the southern half
of the tract resulting in an emergent freshwater marsh ecosystem.
SOILS
0 The N.R.C.S. mapped the soils as the Foreston soil series (Figure 5). This
classification is probably due largely to the amount of fill and drainage that has
occurred. Muckalee type soils still remain in the previous stream bed and in some
adjacent floodplain areas on either side of this heavily impacted section of Rowel
Branch.
VEGETATION
This once dynamic hardwood bottomland is drying out with species such as
privet, honeysuckle, dog fennel and myrtle becoming dominant understory species.
Remnant black gum, red maple, sweet gum and alder can be found in the overstory
section. Dominant species are listed in Table 1.
MITIGATION
A total of 16.1 acres of riverine forest will be restored through the re-routing of
the existing flow through the previous run of Rowel Branch (Figure 6; Table 2). Existing
fill will be removed. Forested riverine vegetation will be planted in the restored areas.

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HYDROLOGICAL RESTORATION
The existing diversion canal will be filled to divert all flow back through the
restored riverine system. The existing fill will be removed and contoured to natural
grade. The channel in the restored wetland will be restored to the grade of the
previous stream bed. Topographical data (Figure 7) indicate that the floodplain is
0 lower and wider than the existing canal; therefore the restoration will not cause
upstream flooding.
VEGETATION RESTORATION
The floodplain areas restored by the removal of existing fill will be planted with
bare root seedlings at a density of 435 trees per acre. Species and overall planting
plan is shown in Table 3.
MITIGATION RATIOS AND OFFSET AREAS
In contrast to a concurrent mitigation situation in which mitigation is implemented
after a permit application is approved, up front mitigation will be provided for impacts
which are not expected to occur for several years. By the time any impacts have
occurred, NCDOT will have functioning wetlands in place. Since all mitigation at the
Rowel Branch Tract is restoration, the applicant proposes a 1:1 mitigation ratio. The
mitigation ratios are justified by the close proximity of the tract to the proposed
Wilmington Bypass location, the likelihood of success and the fact that up-front
mitigation will be provided. In addition, the restored ecosystem will remove stormwater
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pollutants to a greater degree from Leland Industrial Park and thus improve
downstream water quality.
The offset areas are shown in Table 2. Mitigation implementation will offset a
total of 16.1 acres of forested riverine wetlands.
0 MONITORING PLAN
Mitigation progress will be monitored for five years or until deemed successful.
Annual monitoring reports will be submitted to both the USACE and DWQ no later than
September 30th of each year. Each report will consist of a simple narrative with data
analysis. Emphasis will be placed on both successful and problem areas. Dated
photographs will be included to document inherent conditions at each plot. Water table
graphs will document hydrology.
HYDROLOGICAL MONITORING
Six (6) shallow automated groundwater monitoring wells will be installed as
I shown in Figure 8. The success criterion will be the documentation of a static water
table at or within 12" of the soil surface for 5% of the growing season during normal
precipitation conditions. The growing season will be defined using N.R.C.S.
guidelines.
VEGETATION MONITORING
Two sample transects will be established as shown in Figure 9. The point

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quarter sampling technique will be used to establish vegetation success. The success
criterion in the forested riverine section will be the survival of 320 trees per acre,
including acceptable volunteer species. Liquidambar styraciflua and Pinus taeda will
not be considered acceptable volunteer species.
0 MITIGATION IMPLEMENTATION SCHEDULE
All grading activities including water diversion, fill removal and weir construction
will be completed prior to December 1, 1999. All vegetation planting will be completed
prior to March 1, 2000.
FINAL PROPERTY DISPENSATION
The larger land parcel will continue to be owned by E.G. Dale. ECOBANK has
acquired a conservation easement for the mitigation area and will maintain
responsibility for the mitigation areas through success. After the success criteria are
fulfilled, ECOBANK will continue to manage the mitigation area in perpetuity, or entrust
P the easement to an appropriate public agency or land trust.
SUMMARY
The implementation of this mitigation plan will provide effective up-front
mitigation for forested riverine and freshwater marsh ecosystems. Water will be
redirected through a previously bypassed ecosystem, thereby restoring hydrology.
Existing fill will be removed. The project will be monitored for five years with clearly

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established success goals.
The project will provide successful mitigation for projected unavoidable
Wilmington Bypass wetland impacts. The project is located within the same watershed
as the proposed impacts and within one half mile of the Bypass right of way.
Implementation will require relatively little manipulation; the water will be merely
redirected toward its original flow regime. The restored ecosystem will remove
stormwater pollutants from the Leland Industrial Park to a greater degree, thereby
improving downstream water quality. Additionally, the mitigation will be up-front. By
the time impacts occur, NCDOT will have successful mitigation in place. Thus, the
Rowel Branch mitigation will effectively offset unavoidable wetland impacts associated
with the Wilmington Bypass.
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