20160742 Ver 2_NCWRC Comments_20190529

Strickland, Bev
From: Leslie, Andrea J
Sent: Wednesday, May 29, 2019 2:52 PM
To: Mularski, Eric
Cc: Brown, David W CIV USARMY CESAW (US); Homewood, Sue; Ferguson, Jeff C;
Macemore, John W.; Goudreau, Chris J.
Subject: RE: [External] Cedar Cliff Hydroelectric Development Auxiliary Spillway Upgrade
Project - Section 404/401 Amendment #2
Hi Eric,
NCWRC staff have reviewed the documents you sent in your May 16, 2019 email. We are providing the
following comments on the plan sheets. Please contact Jeff Ferguson [(828-231-3517); please cc me if via email]
to discuss these comments.
Keynote #1 on sheet CCL -0104-021 states, "Docks are to be removed by others prior to
construction." There is a standard floating dock adjacent to the ramp. NCWRC staff have been
notified that the floating dock sections will need to be removed and stored off site prior to the start of
construction. There is also an old fixed dock in place adjacent to the old concrete ramp. Please verify
who will be responsible for removal of this dock.
2. The old concrete ramp located between the floating and fixed dock continues to be used for launching
canoes and kayaks at this access area. Will the existing concrete need to be removed prior to or
following construction and removal of the access road? Will that be decided based on the condition of
the concrete remaining following removal of the construction access? If the concrete is to be removed,
is there a plan for shoreline stabilization at this location?
3. The proposed Ditch #6 along with the construction of a rock vane plug and earthen berm between the
ditch and ramp approach (sheet CCL -0104-020) should help with the sediment issues at the ramp. The
longitudinal slope in Ditch #6 between the proposed 2024 & 2021 contours flattens out relative to the
upstream and downstream channel slopes and at a point just below where flow from Kiesee Creek
enters Cedar Cliff Lake at normal levels. It is likely that sediment carried by the creek following heavy
rains will continue to deposit in this area. Over time, that section of the ditch channel may be filled in
with sediment. Flow from the creek below the lake surface could then overtop the proposed berm and
cut a new channel back through the ramp approach area. Has any modeling of sediment flow through
Ditch #6 been done to verify that the channel slopes and dimensions will be sufficient to keep sediment
moving from the mouth of the creek through to the proposed end of channel at E1.=2300'?
4. Detail #3 on sheet CCL -0105-012 shows a typical section of the proposed rock vane. Is there a
specification of size and gradation for rock to be used?
5. Detail #4 on sheet CCL -0105-012 is the typical section for the temporary construction road. It will be
built 3'± thick with surge stone placed over a geotextile layer. What are the plans for disposal or reuse
of this stone after the temporary construction access road is removed?
6. Keynote #2 on sheet CCL -0104-021 states, "Contractor shall maintain aggregate base on parking lot in
good condition." Will this plan include details for access area site improvements to stormwater
drainage & BMPs, paving & parking/ADA delineation, etc. following this project? Will the access area

improvements be by a different designer & contractor? What will the timeframe be for access area
improvements following the dam modification project and drawdown?
Thank you,
Andrea
Andrea Leslie
Mountain Habitat Conservation Coordinator
NC Wildlife Resources Commission
645 Fish Hatchery Rd., Building B
Marion, NC 28752
828-803-6054 (office)
828-400-4223 (cell)
www.ncwildlife.org
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From: Mularski, Eric <[e-mail]>
Sent: Thursday, May 16, 2019 10:23 AM
To: 'david.w. brown@ usace.a rmy. mi I' <[e-mail]>; Homewood, Sue
<[e-mail]>
Cc: Leslie, Andrea J <[e-mail]>; Mitchell, Robert K <[e-mail]>; 'John. Eddy@duke-
energy.com' <[e-mail]>; Wise, Jon <[e-mail]>; 'Ala [e-mail]'
<[e-mail]>; Nicholson, Allen (Furber.Nicholson @duke-energy.com) <Furber.Nicholson@duke-
energy.com>; [e-mail]; Banta, Tim <[e-mail]>; Kulpa, Sarah
<Sarah.Kul [e-mail]>; Little, Michael <[e-mail]>
Subject: [External] Cedar Cliff Hydroelectric Development Auxiliary Spillway Upgrade Project - Section 404/401
Amendment #2
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
am nc. ov
Mr. Brown & Ms. Homewood,
On behalf of Duke Energy, HDR is requesting an amendment to the previously approved Section 404 (Action ID 2015-
02543) and Section 401 (DWR# 2016-0742) Individual Permit for the Cedar Cliff Development Auxiliary Spillway Upgrade
Project (Project). As part of the amendment, Duke Energy would like to include the revised water quality monitoring plan,
an update to the USACE Individual Special Condition 20.0 regarding required depth of Turbidity Barriers, and
authorization for additional impacts to Cedar Cliff Lake to accommodate the proposed Cedar Cliff Access Boat Ramp —
Temporary Construction Access Road. Brief descriptions of these components are described below.
• Water Quality Plan — A rock spoil assessment was initiated following internal review of the subsurface
investigation report that indicated the presence of pyrite material in rock core samples in the auxiliary spillway
rock face. These findings were discussed during a Project status update meeting with the environmental

regulatory agencies (including the U.S. Army Corps of Engineers, NC Division of Water Resources, US Fish and
Wildlife Services, and NC Wildlife Resources Commission) on February 8, 2018. The recommendation was made
to develop a Water Quality Monitoring Plan to gather baseline data as well as post -construction data as a due
diligence measure to ensure that placement of all excavated material from the auxiliary spillway into the reservoir
would not adversely affect water quality.
Duke Energy developed a draft Water Quality Monitoring Plan and submitted the document to the agencies for
review. On June 6, 2018, a teleconference was held to discuss the proposed Water Quality Monitoring Plan. Per
recommendations made during the second meeting, the plan has been revised to include a Data Review and
Reporting Requirements section (see attached). The revised Water Quality Monitoring Plan will be attached to the
Section 404/401 Individual Permit amendment.
• Turbidity Barriers - Duke Energy requests that SAW -2015-02543 Special Condition 20.0 regarding Turbidity
Barriers be revised to read; "Prior to the initiation of any of the work authorized by the permit, the Permittee shall
install floating turbidity barriers with weighted skirts that extend to a depth of at least 5 feet around all work areas
that are in, or adjacent to, surface waters. The turbidity barriers shall remain in place and be maintained until the
authorized work has been completed and all erodible materials have been stabilized."
Cedar Cliff Access Area - Temporary Construction Access Road — Duke Energy would like to include an
additional barge access area at the existing North Carolina Wildlife Resources Commission's Cedar Cliff Access
Area to support the Project. This will require an approximately 550 -foot -long temporary access road to the
proposed barge location. The Cedar Cliff reservoir will be drawn down approximately 30 feet in September 2019
after Labor Day to support the installation of the new spillway hoist, maintenance of the radial gate, and the
Project. The required reservoir drawdown will be sustained over the course of approximately 25 months. The
barge access temporary construction road is necessary to maintain access to the Cedar Cliff reservoir for
equipment and material support for the Project during the 25 -month period. Duke Energy is proposing to install an
approximately 500 -foot long temporary stone construction access road below the Cedar Cliff Reservoir full pond
elevation of 2,330 feet above mean sea level (feet msl). The proposed road will terminate at the 2,300 ft msl
reservoir drawdown elevation for barge access (Drawing CCL -0104-021).
Flow from Kiesee Creek has eroded the existing floating boat dock and sediment has been deposited in the
shallow portion of the reservoir. Duke Energy is proposing to excavate the excess sediment from the reservoir to
elevation 2,322 ft msl as shown on Drawing (CCL -0104-020). All excavated material will be deposited in upland
areas. Installation of a permanent rock vane is proposed to deflect flow from Kiesee Creek away from the boat
launch. A permanent rock ditch (Ditch 6 on the attached plans) parallel to the proposed access road will be
installed to promote flow to the reservoir during the drawdown period. Ditch 6 and rock vane will remain after
construction to promote flow away from the boat launch. To facilitate the construction of Rock Ditch 6 a temporary
pump -around scheme will be employed along a section of Kiesee Creek as shown on Drawing CCL -0103-012.
The proposed limits of the disturbance (LOD) area below the 2,330 ft msl full pond elevation is approximately 1.41
acres. A list of additional impacts below full pond elevation that are requested to be considered as part of this
404/401 permitting addendum are included in the table below.
SHEET Number
Type of Impact
Permanent Impacts
Temporary Impacts
CCL -0103-012
Dewatering
0 acres
45 linear feet
Pum - Around of Kiesee Creek
CCL -0104-020
Excavation
0 acres
0.49 acres
CCL -0104-021
Barge Access Road (Fill)
0 acres
0.49 acres
2,065 cubic yards of rock fill
CCL -0104-020
Rock Ditch
0.70 acres
0 acres
(700 cubic yards of rock fill)
CCL -0104-020
Rock Vane
0.03 acres (100 cubic yards
0 acres
of rock fill
Attached to this email are the revised Duke Energy Water Quality Monitoring Plan and the proposed Cedar Cliff Access
Area Grading Plans and Details. We ask that you review the attached plans and include the additional impacts as part of
Duke Energy's Section 404/401 Individual Permit authorization.
Please do not hesitate to contact me if you have questions regarding this permit amendment request.

Thank you,
Eric Mularski, Pws
Environmental and Regulatory Team Lead
HDR
440 S. Church Street
Charlotte, NC 28202
D 704-973-6878 M 704-806-1521
Eric. m u larski(cD_hdrinc.com
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