20160742 Ver 1_More Info Received_20161020

F)1
October 20, 2016
Mr. David Brown
U.S. Army Corps of Engineers
Asheville Regulatory Field Office
151 Patton Avenue, Room 208
Asheville, NC 28801-5006
Subject: Duke Energy— Cedar Cliff Development Auxiliary Spillway Upgrade Project
USACE Action ID 2015-02543
Response to Section 404 Individual Permit Application Public Notice
Comments
Dear Mr. Brown:
HDR, on behalf of our client Duke Energy Carolinas, LLC (Duke Energy), is submitting the
following responses to comments received by the U.S. Army Corps of Engineers (USACE)
during the public notice period for the Cedar Cliff Development Auxiliary Spillway Upgrade
Project's Section 404 Individual Permit application. The comment letters were emailed by
the USACE to HDR and Duke Energy on September 21, 2016 and excerpts are presented
below, organized alphabetically by resource agency. No comments were received from the
general public.
National Oceanic and Atmosphere Administration (NOAA) National Marine Fisheries
Service (NMFS) — letter dated August 17, 2016
Comment#1 - (Page 1, 2nd paragraph): "Based on the information provided in the public
notice, the proposed project would NOT occur in the vicinity of essential fish habitat (EFH)
designated by the South Atlantic Fishery Management Council or NMFS."
Response: No action required.
North Carolina Department of Natural and Cultural Resources State Historic
Preservation Office— letter dated August 30, 2016
Comment#1 — (Page 1, 2nd paragraph): "Based on our knowledge of the area, it is unlikely
that any archeological resources that may be eligible for inclusion in the National Register
of Historic Place will be adversely affected by the project."
Response: No action required.
hdrinc.com
400 South Church Street Suites 900&1000,Charlotte,NC 28202-2075
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Mr. David Brown
October 20,2016
Page 2
Comment#2 — (Page 1, 3rd paragraph): "The East Fork Hydroelectric Project is eligible for
listing in the National Register of Historic Places (NRHP) under Criterion A for
"Engineering." However, when the East Fork Hydroelectric Project was evaluated in 2014,
the Cedar Cliff Development (JK0729), was determined to be a non-contributing element
of the historic property. Therefore, proposed improvements to the Cedar Cliff Development
dam will not diminish the integrity for which the East Fork Hydroelectric Project is
considered to be historic.
Response: No action required.
Comment#3— (Page 1, 4th paragraph): "Before improvements at Cedar Cliff are initiated,
we request photographs thoroughly documenting the current conditions of the dam and its
surroundings. Please refer to our guidelines for labeling and submitting digital images at
http://www.hpo.ncdcr.gov/digital/NCHP0 Digital Photo Policy.html."
Response: Duke Energy will take photographs to document the existing conditions of the
Cedar Cliff Dam and its surroundings prior to initiating improvement activities.
Photographs will be labeled and submitted to the State Historic Preservation Office
according to their guidelines.
North Carolina Wildlife Resources Commission (NCWRC) — letter dated September
1, 2016
Comment#1 (Page 1, 4th paragraph): "The chosen alternative will allow Duke to minimize
impacts to streams and wetlands; however, it will impact the public's use of Cedar Cliff
Lake. NCWRC and Duke Energy have discussed options to offset impacts to angling due
to lake drawdown and loss of lake acreage. The permit application proposed installing fish
attractors. In lieu of fish attractors, NCWRC has proposed that Duke Energy renovate the
public access area on Cedar Cliff Lake in order to reduce erosion at the site and improve
public access."
Response: Duke Energy is receptive to implementing improvements at the Cedar Cliff
Access Area in lieu of installing fish attractors as mitigation for recreational impacts during
the reservoir drawdown. A meeting at the Cedar Cliff Access Area was held on September
20, 2016 between Duke Energy and NCWRC staff to discuss potential improvements.
Duke Energy is in the process of evaluating alternatives to address erosion concerns and
enhance public access at the site. Duke Energy will work closely with NCWRC to develop
an implementation plan for these improvements.
Comment#2 - (Page 2, 1st paragraph): "As the lake will be drawn down 30 feet for a
considerable period of time, we recommend that Duke Energy assess the need for erosion
control measures after the lake has been drawn down and install remediation measures as
needed."

Mr. David Brown
October 20,2016
Page 3
Response: In compliance with the North Carolina Sediment Pollution Control Act of 1973,
Duke Energy will develop and submit an Erosion and Sediment Control Plan to the North
Carolina Department of Environmental Quality (NCDEQ). The plan will identify and monitor
erosion problem areas and implement measures to mitigate erosion along the exposed
reservoir banks during the drawdown period. Erosion and sediment control devices may
include installation of sediment logs in the exposed reservoir bottom and deployment of
turbidity curtains in the lake to control silt and sediment from entering the reservoir. An
additional turbidity curtain may be placed downstream of the project in the East Fork
Tuckasegee River to protect downstream aquatic resources. Erosion and sediment control
devices will be installed and monitored throughout the duration of the project and
associated drawdown period.
Comment#3 - (Page 3, 2nd paragraph): "There is no information provided in the permit
application on lake drawdown and refill methods. According to Duke Energy staff,
agencies will be consulted before they file a drawdown plan with FERC."
Response: A drawdown and an associated sediment management plan will be developed
to minimize impacts to aquatic resources in Cedar Cliff Lake during the drawdown and
recharge period. The drawdown plan will be provided to the agencies for a 30-day review
and comment prior to submittal to FERC for approval. A preliminary reservoir drawdown
and recharge schedule is provided below; however, this schedule is dependent on the
engineering design review and approvals from federal and state agencies, and may be
subject to change.
Initiate Reservoir Drawdown — 7/24/2018
o Drawdown rate —3 feet per day (or 0.13 foot per hour)*
o Drawdown duration — 10 calendar days—from 7/24/2018 until 8/2/2018
Initiate Cedar Cliff Development Auxiliary Spillway Upgrade activities —7/31/2018
o Estimated construction activities duration —360 work days (72 weeks or 16
months)—from 7/31/2018 until 11/30/2019
o Initiate reservoir recharge — 12/16/2019
o Recharge rate— 3 feet per day (or 0.13 foot per hour)*
o Reservoir recharge complete — 12/26/2019
* Drawdown/recharge rates and schedule may be modified to account for any concerns
after the agency review period and may be subject to change based on actual East Fork
Hydroelectric Project inflow at the time of the drawdown/recharge activities.
U.S. Fish and Wildlife Service (USFWS) — letter dated August 19, 2016
Comment#1 - (Page 2, 2nd paragraph): "We appreciate the proposal to implement the
conservation measures to avoid impacts to Indiana Bat and Northern Long-Eared Bat.
However, we believe an additional measure is necessary if emergence surveys are

Mr. David Brown
October 20,2016
Page 4
conducted before the removal of random tree(s) during the summer maternity roost period.
If emergence surveys are conducted, and bats are observed using the tree(s) to be
removed, we recommend that this office be contacted to establish a plan for proceeding
before the tree(s) is removed. If the above stated measures are implemented into project
plans (including our recommendation), we concur with a "may affect, not likely to adversely
affect" determination for Indiana Bat and Northern Long-Eared Bat; and the consultation
requirements under section 7 of the Act have been fulfilled"
Response: Duke Energy will comply with the additional implementation measures
recommended by USFWS to avoid impacts to Indiana Bat and Northern Long-Eared Bat.
The USFWS Asheville Regulatory Field Office will be contacted when random tree(s) need
to be removed during the summer maternity roost period. Emergence surveys will be
initiated if proposed tree(s) are determined to be suitable maternity roost trees. A
conservation plan will be established between Duke Energy and USFWS if bats are
observed using the tree(s) prior to the tree(s) being removed.
Comment#2 - (Page 3, 2nd paragraph): "The Public Notice (PN) included a statement that
erosion control would be addressed as established in the Shoreline Management Plan for
the project. We are not aware of any specific information on the Shoreline Management
Plan concerning erosion control measures for a reservoir drawdown of the magnitude
necessary for the proposed project. We recommend that Duke Energy develop a plan to
monitor and mitigate for erosion along the exposed reservoir banks. After rain events,
areas near storm water outfall pipes or culverts that release high velocity discharges into
exposed banks should be inspected for erosive reels or mass wasting. The plan should
include measures that will be implemented should erosive/mass wasting areas be found
that are contributing sediment to the river channel. We recommend the use of straw bales
or other devices at problem sites to decrease velocity of waters, decrease erosion, and
minimize the amount of sediment released. Any problem areas should be documented.
Information on documented problem areas should be maintained to focus on erosion
control during any future drawdown."
Response: Duke Energy will submit an Erosion and Sediment Control Plan to the NCDEQ
detailing monitoring and mitigation measures during construction and the reservoir
drawdown period, as described above in HDR's response to NCWRC Comment#2. An
accompanying sediment management plan will be submitted with the drawdown plan.
Comment#3 - (Page 3, 3rd paragraph): "The PN indicated that the water level in the
reservoir will be drawn down about 30 feet for a duration of 14 to 16 months to facilitate
construction of the spillway modifications. The PN did not include a drawdown schedule
for the project. To ensure that aquatic resources within the reservoir are not adversely
affected by the drawdown of the reservoir, we recommend that Duke Energy consult and
reach an agreement with the USFWS, other natural resources agencies, and regulatory

Mr. David Brown
October 20,2016
Page 5
agencies concerning any reasonable and necessary measures to minimize the impacts of
the drawdown."
Response: A drawdown plan will be developed and provided to agencies for a 30-day
review and comment prior to submittal to FERC for approval. A preliminary
drawdown/recharge schedule is described above in HDR's response to NCWRC
Comment#3.
On September 23, 2016, Duke Energy received a Request for Additional Information from
the North Carolina Division of Water Resources (NCDWR). The Section 401 Individual
Water Quality Certification for this project is on hold until the NCDWR receives a response
to the public notice comments. A copy of this letter will be forwarded to the NCDWR.
Thank you for reviewing HDR's responses to public notice comments. If the USACE would
like to schedule a meeting with the commenting resource agencies or should our
responses require further clarification, please contact me at [phone] or
[e-mail].
Respectfully,
HDR Engineering, Inc. of the Carolinas
Eric Mularski, PWS
Senior Environmental Scientist
cc: Jon Wise— Duke Energy
John Eddy— Duke Energy
Tim Banta — HDR
Sue Homewood - NCDWR