20081111 Ver 1_WRC Comments_20080728

North Carolina Wildlife Resources Commission 0
MEMORANDUM
TO:
FROM:
DATE:
SUBJECT
Cyndi Karoly, 401 Certification Unit
NC Division of Water Quality
Ron Linville, Regional Coordinator ZWW
Habitat Conservation Program
July 25, 2008
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BCS Holdings, Robinhood Manor, Unnamed Tributary Muddy Creek, DWQ No.
2008-1111, Forsyth County
The applicant proposes to culvert streams for site access. Biologists with the North Carolina
Wildlife Resources Commission are familiar with habitat values in the area. These comments
are provided in accordance with the provisions of the Fish and Wildlife Coordination Act (48
Stat. 401, as amended; 16 U.S.C. 661-667d) and the North Carolina Environmental Policy Act
(G.S. 113A-1 through 113A-10; NCAC 25).
The project is to develop a mostly wooded site into an apartment complex. Impacts to perennial
waters for two (2) crossings are indicated to total 145 linear feet. A permanent road crossing
using a dual culvert of 54" x 110' is indicated as is a temporary (construction) single barrel
culvert of 36" x 35'. No listed threatened or endangered species are known for this area. Muddy
Creek supports warm water aquatic life and fish species. Stormwater issues and diminished
water quality (aquatic habitat) appear to be substantial concerns in this urbanizing area of
Forsyth County.
Based on our review of the application, we will not object to the project providing the following
recommendations are implemented:
1. If any concrete will be used, work must be accomplished so that wet concrete does
not contact stream water.
2. Bridges are recommended for all permanent roadway crossings of streams,
floodplains and associated wetlands to eliminate the need to fill active floodplains.
Floodplain capacities and floodplain functions must be maintained with bridges and
culverts. If culverts must be used, culverts should be designed and installed to allow
Mailing Address: Division of Inland Fisheries • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fag: [phone]

Robinhood Manor Page 2
Jul} 25, 2008
passage of aquatic organisms. Culverts 48" or larger should be buried at least a foot
(12") below the streambed. Culverts less than 48" diameter should be buried to a
depth equal to or greater than twenty (20) percent their size to provide aquatic life
passage. These measurements must be based on natural thalweg depths. Culverts
should be situated so that no channel realignment or widening is required. Widening
of the stream channel at the inlet or outlet of structures causes a decrease in water
depth and velocity which result in sedimentation and reduction of aquatic passage.
Flat concrete aprons between wing-walls must not be used. Riprap must not be
placed in the streambed. If multiple culvert barrels are needed, a base flow barrel(s)
should be installed as indicated above while any additional barrels should be placed
so that their floors are located on the active bank full elevation. These bank full
barrels should be connected to active floodplain benches to provide natural
dimensions for the base flow channel with sufficient water depth during low or
normal flows to accommodate movement of aquatic species. If culverts are long
and/or sufficient slopes exist, alternating baffles should be provided in a manner that
conforms to channel bends upstream and downstream, mimics natural meanders,
prevents upstream scour and downstream deposition, contains typical bed load
materials, and provides resting areas for aquatic species. If multiple barrels are used,
at least one pipe or barrel should be designed to remain dry (except for flood events)
with a floor material that is easily used by terrestrial wildlife for passage.
3. Temporary crossing areas should be fully restored using state-of-the-art natural
channel design and construction methods. Restored streams and stream banks should
be planted with autochthonous (native) plants like silky dogwood, red maple, silky
willow, tag alder, black willow, sycamore, river birch, or other native woody species.
4. Due to the amount of imperviousness in the area, stormwater management should be
provided. The post construction hydrograph should not exceed preconstruction
conditions. Sound stormwater management should require post construction runoff
conditions to mimic and maintain natural stream flows and stream recharge regimes.
Stormwater management should be required for all new and all retrofitted projects
within the same municipal service area. Low Impact Development (LID) measures
are recommended. Information on LID practices and measures can be found at
www.lowiMactdevelopmcnt.oru, htti): '; wrww?a.gov/owow!nps!lid.%lidnatl.X>df and
http:Hwww.storm watcrcc,nter: net/.
5. Heavy equipment should be operated from the bank rather than in the stream channel
in order to minimize sedimentation and reduce the likelihood of introducing other
pollutants into the stream.
Thank you for the opportunity to review and comment on this project during the early planning
stages. If you have any questions regarding these comments, please contact me at 336/769-9453.
E-copy: Sue Homewood, DWQ-WSRO
John Thomas, USACOE-RRO