01_Clarke Creek_Response to USACE Comments.pdf

kimley-horn.com 200 South Tryon Street, Suite 200, Charlotte, NC 28202 704-333-5131

April 9, 2024

Amber Lipsky
Regulatory Project Manager
U.S. Army Corps of Engineers, Wilmington District
8430 University Executive Park Drive, Suite 615
Charlotte, NC 28262

RE: SAW-2024-00365 - Response to Request for Additional Information
Clarke Creek Greenway Phase A
Cabarrus County, North Carolina

Dear Ms. Lipsky,

On behalf of our client, the City of Concord, Kimley-Horn is submitting the attached additional information
for the above referenced Project per the Request for Additional Information dated March 7, 2024.

Below is an outline of the USACE comments with a brief narrative addressing each item. The USACE
comments with Kimley-Horn response and explanation are as follows:

1. Could you please provide the T&E report that was sent to USFWS?
Please see attached.

2. The Corps believes this project is more appropriate to verify under NWP 42.
a. Can you confirm discharges at this location will comply with part “C. Regional Conditions
Applicable to NWP 42” (i.e. will not result in above-grade fills that will result in an
increased water surface elevation)? If they do, a “no-rise” certification from FEMA should
not be necessary.
The project is funded through the US Department of Transportation's (USDOT) Congestion
Mitigation and Air Quality Improvement Program (CMAQ) and has been designated on NC
Department of Transportation's (NCDOT) State Transportation Improvement Project (STIP) as
NCDOT #BL-0060. Please see the snip below and click the link to review the NCDOT STIP
projects list. The intention of this project is to provide a safe transportation corridor from a densely
developed residential area to local destinations including Cox Mill Elementary School, Cox Mill
High School, and a future park. As part of the CMAQ funding application, Kimley-Horn calculated
an approximate emission reduction that would result from the construction of this project. The
CMAQ award letter from NCDOT is attached for reference.

Based on the project being identified as a linear transportation project by the USDOT as
demonstrated by the CMAQ funding award and NCDOT, it is our understanding that authorization
under NWP 14 would be a more appropriate and applicable permit for this project.

https://connect.ncdot.gov/projects/planning/STIPDocuments1/NCDOT%20Current%20STIP.pdf

3. Please provide revised impact sheets where the area of grading/fill within wetlands is visually
depicted on the plan sheet and profile. Using colors can be helpful for this. There’s a lot of
linework making it difficult to see impacts clearly.
Please see the attached updated site plans.

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4. Per the notation on the Wetland Data Sheets, please include a site map showing the sampling
point locations. Please also include the location of the enclosed photos on the map. We’re
starting to request that a figure like this be included in all JD requests.
Please see the attached figures showing the Photo and Data Form locations.

5. On some sheets, a Temporary Construction Easement (TCE) is within a wetland. Are temporary
impacts anticipated in these areas?
Temporary impacts only occur within the limits of disturbance which are within the TCE. These
areas are highlighted in blue on the attached plan sheets. Following construction, these areas will
be re-seeded with native vegetation and restored to their pre-construction contours.

6. Can you confirm the boardwalks will be elevated at least 3 feet to allow for high flow events?
Confirmed, please see the attached structure details.

7. Can you elaborate on the purpose and need for wetland fill/grading for Wetland Impacts 1, 3 and
4? Why can boardwalks not be used, or the limits of disturbance be shifted slightly, to avoid
impacts to these areas?
a. For example, Wetland Impact 3 shows impacts due to grading. Why does the fill line ‘jut
out’ in these areas causing the impacts? Could you provide an additional plan view sheet
showing the grading details with the existing wetland/grades and subsequent grading
areas clearly depicted?
In response to your comment, the permanent impacts have been reduced by shifting the
alignment away from the wetland to the greatest extent possible. However, there are still impacts
that cannot be avoided. The minimum cross-section for this two-way facility is 10’ wide, with 2’
grass shoulders, and 3:1 side-slope grading. Kimley-Horn has studied various ways to eliminate
the grading that extends to the wetland area, such as retaining walls or boardwalk structures;
however, since the trail is within a sewer easement, structures cannot be installed in this area.
Kimley-Horn has determined that minimal grading is the least impact solution possible in this
portion of the project corridor.

8. Regarding Wetland Impacts 5 and 6- Mechanized clearing, including the stumping of trees to
facilitate the noted topsoil removal, is considered a permanent conversion impact.
i. Why is the clearing area so extensive for Wetland Impact 5?
The size of the clearing area is necessary for the implementation of a
hydraulically equivalent compensatory storage area that results in no increase in
the 100-year base flood elevation. Please see the attached No-Rise Certification
application.

ii. Please note since this would be considered a permanent impact, you would
exceed the mitigation threshold for this project and the Corps will require
evidence of mitigation credit availability for this project. Conversion impacts can
be mitigated for at a 1:1 ratio.
The areas not covered by the 10’ wide boardwalk will be re-seeded with native
vegetation upon completion of the project. The permanent conversion of the
0.017-acre area covered by the boardwalk will be mitigated at a 1:1 ratio.

9. Do the swale bridge details outlined on Sheet C-7.0 correspond to the bridges shown on sheet C-
4.10 and C-4.15? If so, the concrete footers and associated temporary shoring need to be
accounted for in the wetland impacts. Otherwise, please provide bridge details for the bridges
with footers in wetlands.
Top-down boardwalk construction is proposed throughout the majority of the wetland areas on-
site. Swale bridge locations were specifically selected at crossings to minimize permanent
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wetland impacts to the greatest extent possible. Therefore, swale bridges, and their associated
footers, will not be constructed in wetlands. Structural information can be seen on sheets ST-01 –
ST-11. Additionally, Sheet C-2.0 shows typical sections for the boardwalk (typical section 3) and
pedestrian bridge (typical section 4).
10. Are proposed impacts within a riffle/pool complex?
The proposed impacts will not occur within a riffle pool complex.

11. Is the proposed discharge greater than an average of one cubic yard per running foot below the
OHWM?
a. To process this under the NWP 42, please provide the acreage of impacts below the
OHWM due to these activities.
Please refer to question #1. We are seeking authorization for this project under NWP #13 and 14.

12. On Sheet C-4.10, does the 58 LF of bank stabilization refer to both sides of the bank? The arrow
on the plan view only points to one side, but stream grading is called out on both sides of the
profile view. Should the profile view call out on the right be for wetland grading? The riprap fill is
also not depicted, only grading. Could you provide a profile view that includes where the rip rap
is being placed and indicates the wetland fill/grading impacts as well?
The 58 LF of bank stabilization refers to both banks of the stream. Please see the attached
structure plan view showing rip rap on both sides of the stream as well as the wetland grading
necessary to conduct the bank stabilization.

If you need any additional information to assist in your review of this RFAI Response Package, feel free to
contact me at 980-296-0810 or [e-mail].

Sincerely,

Kimley-Horn and Associates, Inc.

Taylor Kiker, PWS
Environmental Scientist