20080915 Ver 2_WRC Comments_20100614

® North Carolina Wildlife Resources Commission
Gordon Myers, Executive Director
MEMORANDUM
TO: Amanda Jones, USACOE
Asheville Regulatory Field Office
FROM: Chris Goudreau, Special Projects Coordinator U44 Q .-
Habitat Conservation Program
DATE: June 14, 2010
SUBJECT: Linville Embankment Seismic Stability Improvements Project, Burke County;
SAW-2008-2753
Duke Energy Carolinas, LLC (Duke) is proposing to construct a seismic countermeasure stability
berm on the downstream side of the existing Linville Dam on Lake James and replace the
existing powerhouse with a new powerhouse located approximately 400 feet downstream. The
project is necessary to conform to Federal Energy Regulatory Commission requirements to
improve earthquake safety. Biologists with the North Carolina Wildlife Resources Commission
(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. I I3A-1
through I I3A-10; NCAC 25).
The proposed project will impact 0.02 acre of wetlands permanently, 748 linear feet of stream
channel (575 feet permanent; 173 feet temporary) and 39,267 square feet of riparian buffer.
Duke proposes to mitigate for permanent impacts to jurisdictional waters through the North
Carolina Ecosystem Enhancement Program in-lieu fee program of 0.25 acres of wetlands and,
1,008 linear feet of stream channel.
Water flow into the Linville River will essentially be stopped (1-2 cfs) for approximately 90 days
(projected dates May 5 - August 3, 2011) during the switchover from the old powerhouse to the
new powerhouse. Currently, minimum flows in this portion of the Linville River are estimated
to be 30-55 cfs when the powerhouse is not generating. This stoppage of flows will affect 4,846
linear feet of Linville River from the toe of the dam to its confluence with Muddy Creek.
Mailing Address: Division of Inland Fisheries - 1721 Mail Service Center - Raleigh, NC 27699-1721
Telephone: [phone] - Fax: [phone]
Linville ESSI Page 2 June 14, 2010
Duke indicates in the application that several alternatives were investigated to provide flow into
the Linville River during the powerhouse switchover, including pumping water from Lake James
over State Road 1233 or through the Linville Dam. These alternatives are considered by Duke
not to be feasible due to dam integrity issues and significant costs.
During the powerhouse switchover, Duke proposes to gradually reduce flows into the Linville
River, survey the river for stranded fish, and move stranded fish downstream. Furthermore,
water temperatures of the Catawba River (below the confluence of Linville River and Muddy
Creek) will be monitored and additional water may be added to the Old Catawba River tributary
from a newly installed valve at the Catawba Dam in order to reduce the effects of high
temperatures. Finally, Duke proposes to monitor the Catawba River (below the confluence of
Linville River and Muddy Creek) for signs of fish mortality and report the results to the state
agencies on a weekly basis.
The Commission manages the Linville River portion of this area with stocked catchable trout.
However, this reach also supports wild trout and about 12 other fish species. The Commission
manages the Catawba River below the Muddy Creek confluence by stocking fingerling trout, but
this reach also contains wild trout and over 20 other fish species.
Drastically reduced flows during the powerhouse switchover have to potential to negatively
impact aquatic organisms throughout the Linville River and Catawba River reaches. Even if
Duke cannot provide flow into the Linville River reach, they should ensure that flows in the
Catawba River reach are sufficient to prevent damage to the aquatic community. An analysis of
daily minimum flows in the Catawba River near Morganton is provided below.
Catawba River Daily Minimum Flow at Calvin by Month (USGS gage #0213903612)
Percentile April May June July Aug
0 116 87 45 46 41
10 131 106 64 60 56
20 144 113 72 87 71
30 154 120 100 96 78
40 166 127 116 100 89
50 173 135 122 104 94
Also, we believe that Duke's statements in the 404 application package regarding the limits of its
responsibility for any fish kills resulting from the proposed project are out of place and do not
absolve Duke of its obligations under the appropriate state statutes.
The absence of flows in the Linville River reach during the powerhouse switchover portion of
the project will prevent the Commission from stocking catchable trout from mid-April through
July. Fishing opportunities in this very popular fishery will be eliminated for approximately
three months.
Based on our review of the submittal, we will not object to the project as proposed providing the
applicant's proposed avoidance, minimization and mitigation actions and the following
conditions are implemented:
Linville ESSI Page 3 June 14, 2010
1. The powerhouse switchover should be conducted as early in the Spring as possible to
minimize the effects of low flow and high temperatures on aquatic organisms in the
Linville and Catawba Rivers. Despite the impact to fishing opportunities, we recommend
that the work begin in March and be completed by May 30, if at all possible.
2. For the duration of the powerhouse switchover a continuous flow equal to the 30`h
percentile should be maintained in the Catawba River at the former Calvin USGS gage
site to minimize the effects of low flow on aquatic organisms in the Catawba River below
the Muddy Creek confluence. Duke should supplement natural flows as needed by
providing water from the newly installed valve at the Catawba Dam.
3. The Commission should be notified by Duke at least 30 days in advance of the projected
start of the powerhouse switchover in order for staff to adjust stocking efforts and notify
the public of impacts to fishing in the Linville and Catawba Rivers.
4. In channel stream work and land disturbance within the 25-foot wide buffer zone are
prohibited during the trout spawning seasons of October 15 through April 15 to protect
the egg and fry stages of trout. If trout moratorium waivers are needed for this project,
Duke Energy should contact NCWRC fishery biologists to discuss alternative protective
actions and mitigation.
5. Culverts 48" or larger should be buried a foot into the streambed. Culverts less than 48
inches in diameter should be buried to a depth equal to or greater than 20% their size to
allow for aquatic life passage. These measurements must be based on natural thalweg
depths. Aquatic life passage should be ensured during low stream flow or drought
conditions. Any riprap used must not interfere with aquatic life movement during low
flows.
6. Sediment and erosion control measures should adhere to the design standards for
sensitive watersheds (15A NCAC 4B .0124).
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 pollutants into
the water. If equipment must be used in waters, petroleum spill containment equipment
should be readily available. Equipment should be new or low-hour, clean and well
maintained.
9. State-of-the-art natural channel design methodologies should be incorporated into any
stream/channel restorations or relocations. Temporarily impacted waters should be
restored to preconstruction conditions unless alternate natural channel designs determine
better site restoration options.
10. Only native plants should be used for vegetating disturbed areas. Restored streams and
stream banks should be planted with native plants like silky dogwood, rhododendron, dog
hobble, red maple, silky willow, tag alder, black willow, sycamore, river birch, or other
Linville ESSI Page 4 June 14, 2010
native woody species to enhance shading and stability. Maximum available forested
buffers should be provided.
11. We encourage the use of biodegradable natural fiber matting instead of plastic matting to
minimize impingement and entrapment of small wildlife. 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. If you have any questions
regarding these comments, please contact me at 828-652-4360 ext. 223.
E-copy: John Dorney, DWQ-Raleigh
Kevin Barnett, DWQ-ARO