HomeMy WebLinkAbout20071778 Ver 1_WRC Comments_20071031North Carolina Wildlife Resources Commission ~
MEMORANTDUM
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TO: Cyndi Karoly, 401 Certification Unit
NC Division of Water Quality ~ GT ~ ~ 200
FROM: Ron Linville, Re Tonal Coordinator /'~ .,~~ _ ~yATFR (.~UAL~IY
Habitat Conserva ion Program 1~ ANDu A+~D ~7~dP~NA`~t ~RAI~CF4
DATE: October 29, 2007
SUBJECT: Mecklenburg County Parks & Recreation Department, Toby Creek Greenway,
Toby Creek and Tributaries thereof, DWQ No. 24071778, Mecklenburg County
The applicant proposes develop a public greenway. 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 25j.
The project is to develop a recreational greenway that will cross jurisdictional waters of the
United States. Impacts for the project include 0.024 acres of wetland impacts and 2681inear feet
of stream impact of which 145 linear feet are on Toby Creek.
Based on our review of the application, we will not object to the project providing the following
recommendations are included in the project to the extent practicable.
Bridges are generally recommended for all permanent roadway crossings of streams,
floodplains and associated wetlands to eliminate the need to fill and culvert active
streams and floodplains. Floodplain capacities and floodplain functions must be
maintained with bridges and culverts. If culverts must be used, culverts must be
designed and constructed to ensure passage of aquatic organisms. Culverts should be
as short as possible and culverts should not be used for non essential or non linear
crossing purposes. Culverts 48" diameter or larger must be buried at least a foot
(12") below the streambed. Culverts less than 48" diameter must be buried to a depth
equal to or greater than twenty (20} percent of their diameter. Depth of burial must
be based on the stream's natural thalweg depth. Culverts should be aligned and
situated so that no channel realignment or widening is required unless such
modification will improve natural conditions. Widening of the stream channel at the
inlet or outlet of the culvert structure causes a decrease m water depth and velocity
causing sedimentation impacts and reduction of aquatic passage. Flat concrete
aprons between wing-walls must not be used. Riprap must not be placed in the
Mailing Address: Division of Inland Fisheries 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: {919) 707-0220 Fax: (919) 707-0028
Toby Creek Greenway -Page 2 -
October 29, 2007
streambed unless absolutely necessary and if used in channel, it must provide natural
channel dimensions. If multiple barrels are needed, base flow barrels must be
installed as indicated above while additional barrels should be placed with floors
located at the active floodplain or bank full elevation. These elevated barrels must be
connected to the active floodplain or bank full benches to ensure natural stream
dimensions for the base flow channel with sufficient water depth during low flows
and drought conditions to accommodate normally anticipated aquatic movement. If
culverts are long and/or sufficient slopes exist, alternating baffles should be provided
in the base flow barrel in a manner to conform to channel bends upstream and
downstream, to mimic natural meanders, to prevent upstream scour and downstream
deposition, to move and contain typical bed load materials, and to provide resting
areas for aquatic species. When multiple barrels are used, at least one barrel should
be designed and constructed with a floor material easily used for terrestrial wildlife
passage.
2. Remaining jurisdictional waters and wetlands should be buffered by protecting or
providing undisturbed contiguous forested buffers. Buffers should be permanently
preserved as contiguous habitats. For streams that do not support federally listed
threatened or endangered aquatic species, we recommend 50' intermittent and 100'
perennial stream buffers. Maximum available buffers should be provided. Although
not recommended, a walking trail may be placed in the buffer zone providing it is
kept away from streams to the maximum extent practicable, it is pervious, and its
width does not exceed minimum width requirements specified in the Americans with
Disabilities Act (ADA). Aesthetic fencing should be provided to prevent pedestrian
impacts to stream and wetland buffers.
3. Sediment and erosion control measures should adhere to the design standards for
sensitive watersheds (15A NCAC 4B .0124).
4. If any concrete will be used, work must be accomplished so that wet concrete does
not contact stream water.
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.
6. Temporary or permanent native herbaceous vegetation should be established on all
bare soil within five (5) to ten (10) days of ground disturbing activities in the buffer
zone to provide long-term erosion control and wildlife habitat. We encourage use of
natural fiber matting instead of plastic matting to avoid impingement and entrapment
of small animals. Onsite vegetation and materials may be used for stream bank
stabilization when practicable.
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: Allan 3ohnson, DWQ-MRO
Steve Chapin, USACOE-ARO