19930501 Ver 2_Other Agency Comments_20091202

S North Carolina Wildlife Resources Commission 0
Gordon Myers, Executive Director
December 2, 2009
Ms. Loretta Beckwith
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006
Ms. Cyndi Karoly
NCDENR, Division of Water Quality, 401 Unit
1628 Mail Service Center
Raleigh, North Carolina 27699-1628
SUBJECT: Macon County Airport Authority Individual 404 Permit Application
Macon County
Action ID SAW-2009-00321, DWQ No. 93-0501v2
Dear Ms. Beckwith and Ms. Karoly:
The Macon County Airport Authority requested an Individual 404 Permit and 401 Water Quality
Certification to fill 809 feet of streams and 5.72 acres of wetlands in the Iotla Creek watershed. Most of
the stream impact involves a culvert in Iotla Branch for a runway extension. The impacts would be
mitigated by purchasing 1,419 feet of stream and 7.42 acres of wetland credits from the North Carolina
Ecosystem Enhancement Program (EEP). Biologists with the North Carolina Wildlife Resources
Commission (Commission) are familiar with the fish and wildlife resources in the region and have visited
the project area on several occasions. Comments from the Commission on this regulatory action are
provided under provisions of the Clean Water Act of 1977 (33 U.S.C. 466 et. seq.) and the Fish and
Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d).
Mailing Address: Division of Inland Fisheries - 1721 Mail Service Center - Raleigh, NC 27699-1 72 1
Telephone: [phone] - Fax: [phone]
Macon County Airport Page 2 December 2, 2009
Iotla Branch and Iotla Creek support a cool water fish assemblage, but habitat is poor due to agricultural
activities in the watersheds. However, the Little Tennessee River downstream supports several rare
species and it is designated critical habitat for the federally-listed Applachian elktoe and little-wing pearly
mussels and spotfin chub. The elktoe and spotfin populations there have declined appreciably in recent
years.
The Commission offers the following comments and recommendations on this project:
I . It is particularly important that stream sedimentation be minimized during construction because
there are rare species in the watershed. Much of the earthwork for the runway extension has been
completed, so implementation of some best management practices is no longer possible.
Nevertheless, we do ask that any exposed soils in proximity to streams be covered with fiber
matting and seeded immediately after any additional grading occurs. We also recommend that
the U.S. Fish and Wildlife Service be contacted regarding the possible need to avoid in-water
construction during certain times of the year to protect spotfin chub or other listed species. There
is no need to avoid construction during the trout spawning seasons.
2. The project will add impervious cover and increase stormwater run-off that can exacerbate
channel erosion in Iotla Creek. Consequently, we support the implementation of the proposed
stormwater detention units and the stream stability monitoring requested by the U.S. Fish and
Wildlife Service. We ask that the Division of Water Quality carefully evaluate the project's
stormwater impacts and require management practices accordingly.
3. Although fish resources in Iotla Branch are common, it is nonetheless important that the culvert
not prevent recolonization upstream of the airport should populations become extirpated in the
future. The nearly 880-foot long culvert and channel relocation may constitute a blockage to fish
movements; however, this is not a certainty. Slope and velocity in the culvert may not be
limiting, but the lack of light could cause fish to avoid passing upstream. Physical obstructions
such as perched culverts injunction boxes and rip rap covering on the stream bed above the
culvert need to be avoided. We request that the inverts of the inflow and outflow culvert/s in
junction boxes be matched so that hydraulic drops are avoided. To maintain sufficient water
depth for fish, all base flow needs to be routed in a single pipe where double pipes are planned.
Also, the stream bed of the relocated channel must not be covered with rip rap as this could cause
suhsurface stream flow and impede fish movements. To avoid this potential entirely, we
recommend that the relocated channel be constructed using natural techniques instead of a rip rap
armoring.
4. We are pleased that the cumulative impacts of the past and current airport improvement projects
and ongoing maintenance activities will be addressed with compensatory mitigation. However,
we are concerned that wetland mitigation may be delayed, perhaps for an extended period,
because credits from EEP are not yet available in this HUC. This project will require a
Macon County Airport Page 3 December 2, 2009
considerable amount of wetland mitigation. Therefore, we recommend that mitigation be
required concurrent with or within a specified period following impacts. Moreover, consideration
should be given to delaying wetland filling near the airport terminal until credits become
available. This should be possible as filling of these areas is not related to the current runway
expansion project.
Thank you for the opportunity to review and comment on this permit action. Please contact me at (828)
452-0422 extension 24 if there are any questions about these comments.
Sincerely,
?'/• //z .
Dave McHenry
Mountain Region Coordinator
Habitat Conservation Program
Cc: K. Barnett, NCDENR, Division of Water Quality, Asheville
B. Tompkins, U.S. Fish and Wildlife Service