20081796 Ver 1_WRC Comments_20090220

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9 North Carolina Wildlife Resources Commission 9
Gordon Myers, Executive Director
MEMORANDUM
TO: Steve Chapin, USACOE
Asheville Regulatory Field Office
FROM: Ron Linville, Regional Coordinator
Habitat Conservation Program
DATE: February 20, 2009
SUBJECT: Crescent Resources, LLC, Rocky River Landing - Phase 2 Multi-Family development, Unnamed
Tributary Rocky River, Cabarrus County
The applicant proposes to impact jurisdictional waters for roadway development. 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 current roadway project will impact 0.98 acres of wetlands and 150 linear feet of stream. Previous impacts for
Phase 1 of the development are indicated as 0.49 acres of wetlands and 150 linear feet of stream. Cumulative
impacts for these accesses only will include 1.62 acres of wetlands and 300 linear feet of stream. Impacts from
Phase 1 were mitigated though payment to the NC Ecosystem Enhancement Program. The Rocky River supports
warm water aquatic habitats and is known to contain physical habitats suitable for freshwater mussels although
diminished water quality is believed to severely limit aquatic species. The Rocky River is a 303 (d) listed stream.
The lack of aquatic species in the area is probably related to poor water quality caused by stormwater issues,
hydrograph modifications, and elevated pollutant loading related to land manipulation and development. Without
stormwater management, the protection of functional wetlands, and substantial provision of undisturbed forested
buffers, these conditions will worsen. Both aquatic and terrestrial habitats will be further diminished in the area.
Based on our review of the submittal, we are concerned that the current Phase 2 does not include provisions
indicated in the spring of 2007 for preserving the "remaining approximately streams, wetlands, riparian berms and
other adjacent upland natural areas within a conservation easement or similar protective mechanism" as we believed
had been indicated in earlier site submittals. The US Army Corps of Engineers (COE) and the NC Division of
Water Quality (DWQ) should determine whether or not these protective covenants should be provided. Providing
the COE and DWQ determine that any protective covenants promised have been provided, we will not object to the
project providing the following conditions are implemented:
1. Any previous stream and wetland preservation commitments should be evaluated for Section
404 Permit and Section 401 Certification compliance.
Mailing Address: Division of Inland Fisheries • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] - Fax: [phone]
Rocky River Landing - Phase 2 Page 2
February 20, 2009
2. Wetland mitigation should occur within the immediate project area since the Rocky River is
listed as a 303(d) impaired ecosystem. Payment to the NC Ecosystem Enhancement Program or
similar entities for distant mitigation sites should not be permitted.
3. Stormwater management should be provided for both Phase 1 and Phase 2 that restores and
maintains pre-development hydroggpLluc conditions to the maximum extent possible.
4. Bridges are recommended for all permanent crossings of streams, floodplains and associated
wetlands to eliminate fill in active streams and floodplains. Floodplain capacities and floodplain
functions should be maintained or restored.
5. Generally, where culverts are permitted, culverts should be designed and constructed to ensure
passage of storm events and passage of aquatic organisms during low flow conditions. 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 in water depth and velocity causing sedimentation impacts and
reduction of aquatic passage. Piping should be large enough to prevent high velocity erosion (faucet
effect) on the downstream end and erosive swirling on the upstream end. Bottomless arch culverts
should be large enough and installed in a manner that a) the active stream and bank full benching can
be accommodated within the structure and b) significant floodwaters can access the floodplain without
structural or riparian zone damage. Flat concrete aprons between wing-walls should not be used.
Riprap should not be placed in the streambed unless absolutely necessary and if used in channel, it
must provide natural channel dimensions. If multiple barrels are installed, base flow barrels should 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 should 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 by terrestrial
wildlife and possibly for a local greenway trail. Plastic pipes should be corrugated (not smooth or
slick) on the inside so that bed load materials can be established to provide and maintain natural
substrates.
6. Stringent erosion control measures should be installed where soil is disturbed and maintained
until project completion.
7. If any concrete will be used, work must be accomplished so that wet concrete does not contact
stream water.
8. 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: Allan Johnson, DWQ-MRO
Becky Fox, US EPA