20080915 Ver 1_2016-11-02 Letter to FERC Lookout Shoals_20161102

DUKE
ENERGY®
November 2, 2016
The Honorable Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, DC 20426
RE: Completed Assessment of Generation Scenario Flows and
Outline of Project Compliance Tool Enhancements
Catawba-Wateree Hydro Project P-2232-631
Lookout Shoals Development
Dear Secretary Bose:
Water Strategy, Hydro Licensing,
and Lake Services
Duke Energy
526 S. Church Street/ EC12Y
Charlotte, NC 28202
In accordance with Article 401 and Appendix E, A-2.0, of the Catawba-Wateree Hydro
Project (Project) License, the year-round required Minimum Continuous Flow from the
Lookout Shoals Development is 80 cubic feet per second (cfs). On April 29, 2016, Duke
Energy Carolinas, LLC (Duke Energy) notified the Federal Energy Regulatory
Commission (Commission) of an April 24, 2016 deviation from the required Minimum
Continuous Flow at the Lookout Shoals Development initiated by a trip of an operating
minimum flow hydro unit.
The Commission replied on June 6, 2016 and requested Duke Energy to take steps to
improve the accuracy of flow monitoring methods employed at Lookout Shoals
Development. Specifically, Duke Energy was asked to respond to the Commission by
September 3, 2016, with either an improved (increased accuracy) flow assessment
method or a plan to develop such an improved methodology.
On August 23, 2016, Duke Energy proposed a study to address improvement in
quantification of flows (Enclosure 1) explaining that flows related to varying operational
conditions (including flows associated with minimum flow units) were to be measured
using an acoustic Doppler current profiler (ADCP). Flow measurement results would
then be referenced to a USGS gage height sensor recently installed in the Lookout
Shoals tailrace in order to develop a rating curve for that gage. The gage height sensor
is a component of a water quality monitoring station which will subsequently be used in
monitoring the Lookout Shoals Hydro tailrace for compliance with water quality
standards.

The Honorable Kimberly D. Bose, Secretary
November 2, 2016
Page 2
By copy of the August 23, 2016 letter, Duke Energy initiated consultation on the study
plan with resource agencies. Resource agency responses were in agreement with the
justification for the study, which included a brief interruption of the Minimum Continuous
Flow (Enclosure 2). The study was carried out October 3, 2016. This notification
provides flow study results, and details how Duke Energy is currently implementing the
study findings to improve compliance assessments of the Lookout Shoals
Development's Minimum Continuous Flow requirement.
The October 3, 2016 flow measurement study was conducted downstream of the
Development as described in Enclosure 1, with the following exceptions:
• The right (east side) terminus of the ADCP transects that were run to measure
leakage and minimum flow unit generation flows (transect location #1) was
slightly downstream of where shown to avoid instrument interferences adjacent
to the wingwall.
• Flows and turbulence associated with generation by a single, larger unit proved
suitable to be measureable at transect location #1. Therefore, flows associated
with this generation scenario (Unit 2 generation only) were measured at transect
location #1, rather than downstream at transect location #3 as outlined in the
study plan.
• The order of generation scenario testing was slightly modified from the plan;
nonetheless, all planned levels of generation flow releases were assessed.
Testing proceeded as follows: Minimum Flow Unit A generation; no generation
(for leakage and seepage measurements); Minimum Flow Unit B generation;
Minimum Flow Units A+B generation, larger Unit 2 generation; and finally, larger
Units 1+2 generation.
Replicate and mean flow measurements from the ADCP transects are presented in
Enclosure 3. Rating curves and quadratic equations computed from the averaged
results are presented in Enclosure 4. Using the lower flow rating curve to gain best
accuracy, a gage height of 9.35 ft was computed as approximately corresponding to the
80-cfs Continuous Minimum Flow requirement.
Integrating these results into Duke Energy's Project Compliance Tool required the
USGS staff programming the USGS water quality monitoring station console to transmit
the gage height data to the Duke Energy SCADA receiver. Duke Energy hydro controls
staff subsequently created a new data link (PI tag) to capture, report, and archive the
USGS station 15 -minute tailrace gage height data. Finally, calculations and logical
comparator additions were instituted in the Project Compliance Tool. All of these
changes were implemented on or before October 31, 2016.

W
S
k#

Enclosure 1. August 23, 2016 letter to the Commission detailing a study plan to assess
flows from the Lookout Shoals Development

DUKE
ENERGY®
August 23, 2016
The Honorable Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, DC 20426
RE: Proposed Assessment of Leakage and Minimum Flow
Catawba-Wateree Hydro Project P-2232
Lookout Shoals Development
Dear Secretary Bose:
Water Strategy, Hydro Licensing,
and Lake Services
Duke Energy
526 S. Church Street / EC12Y
Charlotte, NC 28202
In accordance with Article 401 and Appendix E, A-2.0, of the Catawba-Wateree Hydro
Project (Project) License, the year-round required Minimum Continuous Flow from the
Lookout Shoals Development is 80 cubic feet per second (cfs). On April 29, 2016, Duke
Energy Carolinas, LLC (Duke Energy) notified the Federal Energy Regulatory
Commission (Commission) of an April 24, 2016 deviation from the required Minimum
Continuous Flow at the Lookout Shoals Development. We reported that deviation from
the Minimum Continuous Flow was initiated by a trip of an operating minimum flow
hydro unit.
The Commission replied to our notification with a letter dated June 6, 2016. Based on
the information contained in our notification, the Commission requested Duke Energy
take steps to improve the accuracy of flow monitoring methods employed at the Lookout
Shoals Development. Specifically, the Commission required that Duke Energy respond
to the Commission by September 3, 2016, with either an instituted improved (increased
accuracy) flow assessment method, or a plan to develop such an improved
methodology.
Duke Energy has developed a proposed study plan to address the improvement of flow
measurements from the Lookout Shoals Development, with particular emphasis on
measuring low flows that are highly relevant to our required Minimum Continuous Flow
of 80 cfs. In early October, 2016, we plan to measure a series of flows related to
varying operational conditions in the Lookout Shoals tailrace using an acoustic Doppler
current profiler (ADCP; RD Instruments, RiverRay 1200 kHz). Multiple cross sections of
the tailrace will be measured where indicated on Enclosure 1 for selected hydro
operational scenarios, as outlined in the proposed study plan (Enclosure 2).

The Honorable Kimberly D. Bose, Secretary
April 23, 2016
Paye 2
The final flow data determined for each hydro operational scenario will be calibrated
against the recorded USGS tailrace gage height data (i.e., facilitating the development
of a rating curve for the gage). Once this rating is available, we will be able to more
accurately assess flows from the Lookout Shoals Development, including flows near the
80-cfs Continuous Minimum Flow. This gage height -to -flow conversion will be included
in our Project Compliance Tool to provide an improved assessment of flows near our
Continuous Minimum Flow compliance threshold at this site.
This proposed study plan is most closely addressed as Maintenance and Emergency
Protocol (MEP), Abnormal Condition F — Special River Access Circumstances. By
separate copy of this letter transmitted via email, consultation with the Nofth Carolina
Wildlife Resources Commission, the North Carolina DepaFtment of Environmental
Quality, and the United States Fish and Wildlife Service is being initiated on August 23,
2016. Due to the desire to conduct the proposed study in the low -flow, fall season,
Duke Energy respectfully encourages the agencies to respond and advise Duke Energy
as soon as practical of any comments regarding this flow assessment plan, including
the anticipated 2.5 to 3 -hour period of non -generation required to measure the leakage
flow.
Please direct questions to Mark Oakley at [phone] (_ -
ene y�y.car7r) or George Galleher at (I04) 382-5236 ( eorge. a e er(a)u e-
energy.com).
Sincerely,
Jeffrey G. Lineberger, PE
Director, Water Strategy & Hydro Licensing
Duke Energy Carolinas, LLC
Enclosures
cc with Enclosures:
Karen Higgins, North Carolina Department of Environmental Quality
Fred Tarver, North Carolina Department of Environmental Quality
Chris Goudreau, North Carolina Wildlife Resources Commission
Bryan Tompkins, United States Fish and Wildlife Service

Enclosure 1. Location of Existing USGS Gage No. 0214244102 CATAWBA RIVER BL LOOKOUT
SHOALS DAM NR SHARON, NC and Proposed Channel Flow Measuring Transects

Enclosure 2. Proposed Study Plan to Measure Hydro Flows and Calibrate Existing USGS Gage
Height Data
Objective: Develop a rating curve for the USGS Gage No. 0214244102 mounted on the east
wingwall in the Lookout Shoals tailrace.
Target Date: 3 October 2016 (May be rescheduled if weather not suitable, e.g., substantial rainfall)
Operational Scenarios
5:00 AM — One minimum flow unit running
8:00 AM — Shut down all generation
9:00 AM — Staff to examine tailwaters hourly (until flows resumed) for stranded fish, document
occurrence, if any, and take any appropriate actions
10:00 AM — Measure leakage flow at Transect 1 and potential seepage flow at Transect 2
11:00 AM — Start one minimum flow unit (Unit A)
(Start Unit A prior to 11:00 AM if all flow measurements completed satisfactorily)
11:30 AM — Measure Unit A flow at Transect 1
12:00 PM — Start minimum flow Unit B and immediately shut down Unit A
12:30 PM — Measure Unit B flow at Transect 1
1:00 PM — Start Unit A (both minimum flow units operating)
1:30 PM — Measure total flow from Units A and B at Transect 1
2:00 PM — Start Unit 1 and shut down minimum flow Units A and B
2:30 PM — Measure flow from Unit 1 at Transect 3
3:00 PM — Start Unit 2 (both Unit 1 and 2 operating)
3:30 PM — Measure total flow from Units 1 and 2 at Transect 3
4:00 PM — Measurements complete, return to normal operations
NOTES:
1. Generating units to be run as normal at best efficiency setting; flows are partially dependent
on reservoir elevation (head).
2. Measurements for leakage flow and minimum flow unit operation will be derived from
replicate transects between the wingwalls near their lower extent (Transect 1). Attempts will
also be aimed at traversing a transect to the west of the river channel -side wingwall (Transect
2) to examine whether seepage from the dam can be estimated from this point. Higher flow
measurements will be made downstream of the shoals (Transect 3). The required number of
replicate ADCP transects may increase depending on variability of measurements at any given
site.
3. The proposed measurement of leakage will require the 80-cfs Continuous Minimum Flow be
shut down for approximately 2.5 hours, but no more than 3 hours. Our April 24, 2016
monitoring suggests that 2 hours is needed to allow flows in the area to equilibrate so that the
measurements will be representative. Subsequent flow increases related to operation of
additional hydro units in the study plan have been shown in the existing tailrace gage height
records to equilibrate much more rapidly.

Enclosure 2. Consultation with resource agencies on the Lookout Shoals flow study
plan

From: Finley, Keith A
To: Tarver, Fred
Cc: Higgins, Karen; Goudreau, Chris J.; Bryan Tompkins man tompkins(@fws.gov); Oakley. Mark; Galleher, George
A; Dunn, Lynne; Jon Knight (ioncknight(&road runner. com); Lail, Mike
Subject: Re: Proposed Study Plan to Measure Various Operational Flows From Lookout Shoals Hydro
Date: Tuesday, September 27, 2016 5:57:47 PM
Hi Fred,
Thank you for reviewing the work plan. We will be sure to copy to all with our findings in
our subsequent reporting to the FERC.
Regards,
Keith
Sent from my iPhone
On Sep 27, 2016, at 10:48 AM, Tarver, Fred <fred.tarver(.ncdenr.gov> wrote:
*** Exercise caution. This is an EXTERNAL
email. DO NOT open attachments or click links
from unknown senders or unexpected email. ***
Keith,
I communicated with Karen Higgins, head of the 401 Unit, and we agreed that the plan
attached to your email seems necessary and reasonable as proposed. Please provide
us with the final results.
Thanks,
Fred
Fred R Tarver III
Division of Water Resources
NC Department of Environmental quality
1611 Mail Service Center
Raleigh. NC 27699-1611
Email: fred.tarver(@ncdenr.gov
Phone: [phone]
Fax: [phone]
(E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law
and disclosed to third parties.)
From: Finley, Keith A [mailto:Keith. Finleyl@duke-energ_y.com]
Sent: Tuesday, August 23, 2016 3:45 PM

To: Higgins, Karen <karen.higgins(@ncdenr.gov>; Tarver, Fred
<fred.tarver(@ncdenr.g_ov>; Goudreau, Chris J.<chris.goudreau(@ncwildlife.org>; Bryan
Tompkins (br)lan_tompkins(@fws.gov) <bryan_tompkins(@fws.gov>
Cc: Oakley, Mark <[e-mail]>; Galleher, George A
<George. GaIleher(@duke-energy.com>; Dunn, Lynne <Lvnne.DUnn(@duke-
energy.com>; 'Jon Knight (ioncknight(@roadrunner.com)'
<ioncknight(@road run ner.com>; Lail, Mike <Mike.Lail (@duke-energy.com>
Subject: Proposed Study Plan to Measure Various Operational Flows From Lookout
Shoals Hydro
Good afternoon,
In response to a June 6, 2016 request Duke Energy received from the FERC, we are
proposing a study plan to undertake a series of flow measurements in the tailwaters of
the Lookout Shoals Hydro (Catawba -Wateree Hydro Project). Study implementation is
tentatively scheduled for October 3. The results of the planned flow measurements
will allow us to calibrate a tailrace level gage that was included at a recently installed
USGS water quality (water temperature and dissolved oxygen) monitoring site. The
development of a rating for the level gage is expected to improve the accuracy with
which we measure hydro generation flows below the Lookout Shoals Hydro.
By copy of this letter, we are respectfully requesting any comments your agency may
want to provide relative to this proposed effort, as outlined on the attached
document. Thank you in advance for your input on this matter.
Best regards,
Keith Finley
Project Manager II
Duke Energy Water Strategy & Hydro Licensing
O: 980.373.3726
C: 704.533.2960
<image001 Jpg>

Enclosure 3. Replicate ADCP channel transect flow measurements obtained for
selected generation scenarios, October 3, 2016.
ADCP
File #
Time
Flow
(cfs)
Average
Flow
(cfs)
Mean
Gage
Reading
(ft)
Unit A
0
10:08
156
1 10:11 -26.5
2 10:14 250
3 10:16 158
4 10:19 199
5 10:21 256
6 10:24 59
7 10:26 298
8 10:29 155
mean
167.2
9.61
Turbine
Leakage
9
11:52
48
10 11:55 44.9
11 11:57 58
12 11:58 19
13 12:00 73
14 12:02 60
15 12:04 80
16 12:06 44.6
mean
53.4
9.25
Dam
17
12:13
5.1
18 12:16 4.9
Seepage
mean
5.0
N/A
Unit B
19
13:24
131
20 13:27 348
21 13:29 18.9
22 13:31 207
23 13:34 83
24 13:36 104.9
25 13:38 78.7
26 13:40 179
mean
143.8
9.58
Units A& B
27
14:09
240
28 14:11 288
29 14:13 397
30 14:16 161
31 14:18 219
32 14:20 134
mean
239.8
9.82
Unit 2
33
15:06
1083
34 15:09 2360
35 15:15 1515
36 15:18 1709
37 15:20 2177
38 15:22 2109
39 15:24 1675
40 15:26 1970
41 15:28 1903
42 15:30 2170
43 15:32 2228
44 15:34 1763
mean
1888.5
11.24
Units 1 & 2
45
16:05
3330
46 16:08 3382
47 16:10 3385
48 16:13 3553
49 16:15 3540
50 16:19 3540
mean
3455.0
12.06

Enclosure 4. USGS gage height rating curves calculated from October 3, 2016 flow
study at Lookout Shoals Hydro tailrace
3500
w 3000
U
N
2500
m
L
y
2000
3
LL 1500
Q 500
All ADCP Flow Measurements
—Rating Equation (leakage - 2 Unit Flow)
—f—Leakage and Small Unit Flow
Rating Curve (Leakage and Small Unit Flow)
All ADCP Measurements
Y = 362.827x2 - 6,514.580x + 29,253.408
R2 = 1.000
Y = 159.727x2 - 2,715.863x + 11,508.313
R2 = 0.994
9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 13.0
USGS Gage Reading (ft)