Catawba-Wateree 2021 Annual FERC Compliance Report-FINAL 6-29-2022

V
� DUKE
ENERGY
June 29, 2022
The Honorable Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, DC 20426
RE: Duke Energy Carolinas, LLC
Catawba-Wateree Hydro Project No. P-2232
Annual License Compliance Report
Dear Secretary Bose:
WATER STRATEGYAND HYDRO LICENSING
Duke Energy Corporation
Regulated and Renewable Energy
526 South Church Street / EC 12Q
Charlotte, NC 28202
The Duke Energy Carolinas, LLC (Duke Energy) Catawba-Wateree Hydroelectric Project No. 2232
(Project) License', Appendix E, A-5.0, Article - Water Quality Monitoring Plan, and License Appendix
E, A-6.0, Article - Flow and Reservoir Elevation Monitoring, require Duke Energy to submit
compliance reports each year.
The enclosed 2021 Compliance Report for Reservoir Elevations, Flow Releases, and Water Quality
(Annual Report) is submitted to comply with the combined applicable requirements of both the
preceding License Articles. Please note the Appendix Tables accompanying the report, which include
tabulations of Project reservoir elevation, flow release, and water quality data, are submitted in
Microsoft ExcelO file format.
This report has been provided to the N.C. Department of Environmental Quality, Division of Water
Resources, N.C. Wildlife Resources Commission, S.C. Department of Natural Resources, S.C.
Department of Health and Environmental Control, the U.S. Fish and Wildlife Service, the National
Marine Fisheries Service, and the U.S. Environmental Protection Agency.
Please direct questions to Tami Styer at [phone] ([e-mail]).
Sincerely,
?// (;-,-I
Jeffrey G. Lineberger, PE
Director, Water Strategy & Hydro Licensing
Duke Energy
' Issued November 25, 2015; Accession No. 20151125-3023

The Honorable Kimberly D. Bose, Secretary
June 29, 2022
Page 2 of 2
Enclosure
cc w/ enclosures:
Paul Wojoski, NC Department of Environmental Quality
Fred Tarver, NC Department of Environmental Quality
Chonticha McDaniel, NC Department of Environmental Quality
Chris Goudreau, NC Wildlife Resources Commission
Bryan Tompkins, US Fish and Wildlife Service
Elizabeth Miller, SC Department of Natural Resources
Chuck Hightower, SC Department of Health and Environmental Control
Rusty Wenerick, SC Department of Health and Environmental Control
Twyla Cheatwood, National Marine Fisheries Service
Fritz Rhode, National Marine Fisheries Service
Melanie Olds, U.S. Fish and Wildlife Service
Tom McCoy, U.S. Fish and Wildlife Service
Chris Militscher, U.S. Environmental Protection Agency
Randy Herrin, Duke Energy
Lynne Dunn, Duke Energy
Tami Styer, Duke Energy
Phil Fragapane, Duke Energy
Garry Rice, Duke Energy
Sarah Santos, Duke Energy
Alan Madewell, Duke Energy

2021 Catawba-Wateree Hydroelectric Project
Compliance Report
Reservoir Elevation, Flow, and Water Quality
FERC Project Number 2232
Duke Energy Carolinas, LLC
June 2022
DUKE
ENERGY

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Table of Contents
1 Introduction...............................................................................................................................7
1.1 License Article Requirements............................................................................................................7
1.2 CRA Requirements............................................................................................................................8
1.3 Status of FWQIP Physical Modifications and WQMP Requirements in 2021...................................9
2 Development -Specific Article Requirements..............................................................................10
2.1 Bridgewater Development..............................................................................................................10
2.2 Rhodhiss Development...................................................................................................................12
2.3 Oxford Development.......................................................................................................................13
2.4 Lookout Shoals Development.........................................................................................................14
2.5 Cowans Ford Development.............................................................................................................15
2.6 Mountain Island Development.......................................................................................................16
2.7 Wylie Development.........................................................................................................................17
2.8 Fishing Creek Development............................................................................................................19
2.9 Great Falls -Dearborn Development................................................................................................20
2.10 Rocky Creek -Cedar Creek Development.........................................................................................21
2.11 Wateree Development....................................................................................................................22
3 Methods...................................................................................................................................23
3.1 Reservoir Elevation Article Compliance Assessment......................................................................23
3.2 Flow Article Compliance Assessment..............................................................................................24
3.3 Water Quality Compliance Assessment..........................................................................................24
4 Results and Discussion..............................................................................................................26
4.1 Elevation Article Compliance..........................................................................................................26
4.2 Flow Article Compliance..................................................................................................................37
4.3 Water Quality Article Compliance...................................................................................................63
5 References.............................................................................................................................103
Appendices....................................................................................................................................104
Appendix A-1: Excel Spreadsheet - 2021 Hourly Reservoir Elevation Data.........................................104
Appendix B-1: Excel Spreadsheet - 2021 Raw Data Set for USGS Gages and Generation Records .....
104
Appendix C-1: Excel Spreadsheet - Flow Release Data Summary........................................................104
Appendix D-1: Excel Spreadsheet - Water Quality Data Summary......................................................104
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Tables
Table 2-1. Bridgewater Development Normal Minimum Reservoir Elevations for Lake James ................. 10
Table 2-2. Bridgewater Development Tailrace Minimum Continuous Flow Release Requirements......... 11
Table 2-3. Bridgewater Development Catawba River Bypassed Reach Minimum Continuous Flow
ReleaseRequirements...................................................................................................................... 11
Table 2-4. Bridgewater Development Recreational Flow Release Requirements ..................................... 12
Table 2-5. Cowans Ford Normal Minimum Reservoir Elevations for Lake Norman ................................... 15
Table 2-6. Wylie Development Recreational Flow Release Requirements.................................................18
Table 2-7. Wateree Development Normal Minimum Reservoir Elevations for Lake Wateree.................. 22
Table 4-1. Summary of Reservoir Elevation Article Deviations in 2021 and Dates of FERC Notification... 26
Table 4-2. Summary of Flow Article Deviations in 2021 and Dates of FERC Notification ........................... 38
Table 4-3. Summary of All Water Quality Article Deviations in 2021......................................................... 63
Figures
Figure 4-1. Bridgewater Development: Lake James Hourly Surface Elevations, January 1-December 31,
2021...................................................................................................................................................
27
Figure 4-2. Rhodhiss Development: Lake Rhodhiss Hourly Surface Elevations, January 1-December 31,
2021...................................................................................................................................................
28
Figure 4-3. Oxford Development: Lake Hickory Hourly Surface Elevations, January 1-December 31, 2021.
...........................................................................................................................................................
29
Figure 4-4. Lookout Shoals Development: Lookout Shoals Lake Hourly Surface Elevations, January 1-
December31, 2021...........................................................................................................................
30
Figure 4-5. Cowans Ford Development: Lake Norman Hourly Surface Elevations, January 1-December 31,
2021...................................................................................................................................................
31
Figure 4-6. Mountain Island Development: Mountain Island Lake Hourly Surface Elevations, January 1-
December31, 2021...........................................................................................................................
32
Figure 4-7. Wylie Development: Lake Wylie Hourly Surface Elevations, January 1-December 31, 2021...
33
Figure 4-8. Fishing Creek Development: Fishing Creek Reservoir Hourly Surface Elevations, January 1-
December31, 2021...........................................................................................................................
34
Figure 4-9. Great Falls -Dearborn Development: Great Falls Reservoir Hourly Surface Elevations, January
1-December 31, 2021........................................................................................................................
35
Figure 4-10. Rocky Creek -Cedar Creek Development: Cedar Creek Reservoir Hourly Surface Elevations,
January1-December 31, 2021..........................................................................................................
36
Figure 4-11. Wateree Development: Lake Wateree Hourly Surface Elevations, January 1-December 31,
2021...................................................................................................................................................
37
Figure 4-12. Bridgewater Development: Flows measured in the Bridgewater Hydroelectric Station
tailrace at USGS Gaging Station 02138520, January 1-December 31, 2021.....................................
39
Figure 4-13. Bridgewater Development: Flows measured in the Bridgewater Catawba River Bypassed
Reach at USGS Gaging Station 02138816, January 1-December 31, 2021.......................................
39
Figure 4-14. Bridgewater Development: The figure above is excerpted from Figure 4-13 for closer
examination......................................................................................................................................
40
Figure 4-15. Bridgewater Development: Total flow released from the Bridgewater Development (sum of
Bridgewater Hydro tailrace and Catawba River Bypassed Reach flows), January 1-December 31,
2021, to support Public Water Supply and Industrial Processes Article...........................................40
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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Figure 4-16. Bridgewater Development: Recreational flows released for the purpose of float angling,
April -October 2021. Flows were measured at USGS Gaging Station 02138520...............................41
Figure 4-17. Bridgewater Development: Recreational flows released for the purpose of paddling, April -
October 2021. Flows were measured at USGS Gaging Station 02138520........................................42
Figure 4-18. Bridgewater Development: Recreational flows released for the purpose of migratory bird
hunting, October 21-23, 2021. Flows were measured at USGS Gaging Station 02138520. See
Annual Recreation Planning Meeting 2018, FERC Accession No. 20180424-5136 ...........................43
Figure 4-19. Rhodhiss Development: Average daily flows released at the Rhodhiss Development January
1-December 31, 2021........................................................................................................................44
Figure 4-20. Oxford Development: Flows measured at USGS Gaging Station 0214196125 in the Oxford
tailrace, January 1-December 31, 2021............................................................................................45
Figure 4-21. Oxford Development: Recreational flows measured at USGS Gaging Station 0214196125 in
the Oxford tailrace, May -October 2021............................................................................................ 46
Figure 4-22. Lookout Shoals Development: Flows measured at USGS Gaging Station 0214244102 in the
Lookout Shoals tailrace, January 1-December 31, 2021...................................................................46
Figure 4-23. Lookout Shoals Development: Figure above is excerpted from Figure 4-22 for closer
examination...................................................................................................................................... 47
Figure 4-24. Cowans Ford Development: Average daily flows released January 1-December 31, 2021.
Flows were calculated based on generation and spill flow data ...................................................... 48
Figure 4-25. Mountain Island Development: Average daily flows released January 1-December 31, 2021.
Flows were calculated based on generation and spill flow data ...................................................... 49
Figure 4-26. Wylie Development: Wylie tailrace flows recorded at USGS Gaging Station 02145910,
January1-December 31, 2021.......................................................................................................... 50
Figure 4-27. Wylie Development: Recreational flows recorded at USGS Gaging Station 02145910, located
0.5 miles downstream of Wylie, April -October 2021....................................................................... 51
Figure 4-28. Wylie Development: Flows supporting public water supply and industrial processes
recorded at USGS Gaging Station 02147020, located 19 miles downstream of Wylie, January -
December2021................................................................................................................................. 52
Figure 4-29. Wylie Development: Weekly average flows supporting public water supply and industrial
processes recorded at USGS Gaging Station 02146000, located 3.5 miles downstream of Wylie
tailrace, January -December 2021..................................................................................................... 53
Figure 4-30. Fishing Creek Development: Average daily flows released by the Fishing Creek
Development, January 1-December 31, 2021................................................................................... 54
Figure 4-31. Rocky Creek -Cedar Creek Development: Average daily flows released January 1-December
31, 2021, by the Rocky Creek -Cedar Creek Development................................................................ 55
Figure 4-32. Wateree Development: Wateree FWQIP Interim Flow Measures recorded at Wateree
Tailrace from January 1— February 14 and during required continuous 1-unit generation period
(February 15 — May 15)..................................................................................................................... 56
Figure 4-33. Wateree Development: Wateree FWQIP Interim Flow Measure flows recorded at Wateree
Tailrace from (a) May 16—June 15, (b) June 16—July 15, and (c) July 16—August 15. .................. 57
Figure 4-34. Wateree Development: Wateree FWQIP Interim Flow Measure deviations recorded at
Wateree Tailrace from (a) August 16 — September 15, (b) September 16 - October 15, (c) October
16 — November 15............................................................................................................................. 59
Figure 4-35. Wateree Development: Wateree FWQIP Interim Flow Measure deviations recorded at
Wateree Tailrace from November 16 — December 31, 2021............................................................ 59
Figure 4-36. Wateree Development: Recreational flows released by the Wateree Development from
10:00-15:00 on recreational flow release dates, April -October 2021.............................................. 60
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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Figure 4-37. Wateree Development: Flows measured at USGS Gaging Station 02148000 from 13:00-
18:00, allowing three hours for recreational flows released 10:00-15:00 at the Wateree
Development to be fully manifested 7.4 miles downstream at USGS Gaging Station 02148000.... 61
Figure 4-38. Wateree Development: Wateree Flows supporting public water supply and industrial
processes recorded at USGS Gaging Station 02148000, January 1-December 31, 2021.................. 62
Figure 4-39. Example boxplot for representing water quality datasets in this report ............................... 64
Figure 4-40. Bridgewater Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Bridgewater Tailrace at USGS Water Quality Monitoring Station
02138520, April 1-November 30, 2021............................................................................................. 65
Figure 4-41. Bridgewater Development: Summary of daily average dissolved oxygen (DO) concentrations
recorded in the Bridgewater Tailrace at USGS Water Quality Monitoring Station 02138520, April 1-
November30, 2021........................................................................................................................... 66
Figure 4-42. Bridgewater Development: Summary of instantaneous water temperature recorded in the
Bridgewater Tailrace at USGS Water Quality Monitoring Station 02138520, April 1-November 30,
2021................................................................................................................................................... 67
Figure 4-43. Rhodhiss Development: Summary of instantaneous dissolved oxygen (DO) concentrations
recorded in the Rhodhiss Tailrace at USGS Water Quality Monitoring Station 02141500 while
Rhodhiss Hydro Station was generating, April 1-November 30, 2021.............................................. 68
Figure 4-44. Rhodhiss Development: Summary of daily averages of dissolved oxygen (DO) concentrations
recorded in the Rhodhiss Tailrace while Rhodhiss Hydro Station was generating, April 1-November
30, 2021............................................................................................................................................. 69
Figure 4-45. Rhodhiss Development: Summary of instantaneous temperatures recorded in the Rhodhiss
Tailrace at USGS Water Quality Monitoring Station 02141500 while Rhodhiss Hydro Station was
generating, April 1-November 30, 2021............................................................................................ 70
Figure 4-46. Oxford Development: Summary of instantaneous dissolved oxygen (DO) concentrations
recorded in the Oxford Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-
November30, 2021........................................................................................................................... 71
Figure 4-47. Oxford Development: Summary of daily average dissolved oxygen (DO) concentrations
recorded in the Oxford Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-
November30, 2021........................................................................................................................... 72
Figure 4-48. Oxford Development: Summary of instantaneous temperatures recorded in the Oxford
Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-November 30, 2021...... 73
Figure 4-49. Lookout Shoals Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station
0214244102, April 1-November 30, 2021......................................................................................... 74
Figure 4-50. Lookout Shoals Development: Summary of daily average dissolved oxygen (DO)
concentrations recorded in the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station
0214244102, April 1-November 30, 2021......................................................................................... 75
Figure 4-51. Lookout Shoals Development: Summary of instantaneous tailrace temperatures recorded in
the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station 0214244102, April 1-
November30, 2021........................................................................................................................... 76
Figure 4-52. Cowans Ford Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Cowans Ford Tailrace at USGS Water Quality Monitoring Station
0214264790 when Cowans Ford Hydro Station was generating, April 1-November 30, 2021........ 77
Figure 4-53. Cowans Ford Development: Tailrace instantaneous dissolved oxygen (DO) concentrations
from August 1-September 30, 2021, documenting deviations from the North Carolina
instantaneous DO standard of >_ 4.0 mg/L while Cowans Ford Hydro Station was generating........ 78
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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Figure 4-54. Cowans Ford Development: Summary of daily averages of DO concentrations recorded at
USGS Water Quality Monitoring Station 0214264790 in the Cowans Ford Tailrace while Cowans
Ford Hydro Station was generating, April 1-November 30, 2021..................................................... 79
Figure 4-55. Cowans Ford Development: Daily averages of DO concentrations recorded at USGS Water
Quality Monitoring Station 0214264790 in the Cowans Ford Tailrace while Cowans Ford Hydro
Station was generating, August 1-October 1, 2021, documenting deviations from the North
Carolina standard for daily average DO >_ 5.0 mg/L.......................................................................... 80
Figure 4-56. Cowans Ford Development: Summary of instantaneous temperatures recorded in the
Cowans Ford Tailrace at USGS Water Quality Monitoring Station 0214264790 while Cowans Ford
Hydro Station was generating, April 1-November 30, 2021............................................................. 81
Figure 4-57. Mountain Island Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Mountain Island tailrace at USGS Water Quality Monitoring Station
0214267602 while Mountain Island Hydro Station was generating, April 1-November 30, 2021... 82
Figure 4-58. Mountain Island Development: Summary of daily averages of dissolved oxygen (DO)
concentrations recorded at USGS Water Quality Monitoring Station 0214267602 in the Mountain
Island Tailrace while Mountain Island Hydro Station was generating, April 1-November 30, 2021.83
Figure 4-59. Mountain Island Development: Summary of instantaneous temperatures recorded in the
Mountain Island tailrace at USGS Water Quality Monitoring Station 0214267602 while Mountain
Island Hydro Station was generating, April 1-November 30, 2021................................................... 84
Figure 4-60. Wylie Development: Summary of instantaneous tailrace dissolved oxygen (DO)
concentrations recorded in the Wylie Tailrace at USGS Water Quality Monitoring Station
02145910, April 1-November 30, 2021............................................................................................. 85
Figure 4-61. Wylie Development: Summary of daily average dissolved oxygen (DO) concentrations
recorded in the Wylie Tailrace at USGS Water Quality Monitoring Station 02145910, April 1-
November30, 2021........................................................................................................................... 86
Figure 4-62. Wylie Development: Summary of instantaneous tailrace temperatures recorded in the
Wylie tailrace at USGS Water Quality Monitoring Station 02145910, April 1-November 30, 2021. 87
Figure 4-63. Fishing Creek Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Fishing Creek tailrace at USGS Water Quality Monitoring Station
02147310 while Fishing Creek Hydro Station was generating, April 1-November 30, 2021............ 88
Figure 4-64. Fishing Creek Development: Instantaneous dissolved oxygen (DO) concentrations recorded
in the Fishing Creek Tailrace at USGS Water Quality Monitoring Station 02147310 while Fishing
Creek Hydro Station was generating, July 1-August 1, 2021, demonstrating deviations from the
South Carolina >_ 4.0 mg/L instantaneous DO standard.................................................................... 89
Figure 4-65. Fishing Creek Development: Summary of daily averages of dissolved oxygen (DO)
concentrations recorded in the Fishing Creek Tailrace at USGS Water Quality Monitoring Station
02147310 while Fishing Creek Hydro Station was generating, April 1-November 30, 2021............ 90
Figure 4-66. Fishing Creek Development: Summary of instantaneous temperatures recorded in the
Fishing Creek Tailrace at USGS Water Quality Monitoring Station 02147310 while Fishing Creek
Hydro Station was generating, April 1-November 30, 2021............................................................. 91
Figure 4-67. Great Falls -Dearborn Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Great Falls -Dearborn Tailrace at USGS Water Quality Monitoring
Station 021474095 while Dearborn Hydro Station was generating, April 1-November 30, 2021.... 92
Figure 4-68. Great Falls -Dearborn Development: Summary of daily averages of tailrace dissolved oxygen
(DO) concentrations recorded in the Great Falls -Dearborn tailrace at USGS Water Quality
Monitoring Station 021474095 while Dearborn Hydro Station was generating, April 1-November
30, 2021............................................................................................................................................. 93
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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Figure 4-69. Great Falls -Dearborn Development: Summary of instantaneous temperatures recorded in
the Great Falls -Dearborn Tailrace at USGS Water Quality Monitoring Station 021474095 while
Dearborn Hydro Station was generating, April 1-November 30, 2021............................................. 94
Figure 4-70. Rocky Creek -Cedar Creek Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Cedar Creek Tailrace at USGS Water Quality Monitoring Station
02147505 while Cedar Creek Hydro Station was generating, April 1-November 30, 2021.............. 95
Figure 4-71. Rocky Creek -Cedar Creek Development: Summary of daily averages of dissolved oxygen
(DO) concentrations recorded in the Cedar Creek Tailrace at USGS Water Quality Monitoring
Station 02147505 while Cedar Creek Hydro Station was generating, April 1-November 30, 2021. 96
Figure 4-72. Rocky Creek -Cedar Creek Development: Summary of instantaneous temperatures recorded
in the Cedar Creek Tailrace at USGS Water Quality Monitoring Station 02147505 while Cedar Creek
Hydro Station was generating, April 1-November 30, 2021............................................................. 97
Figure 4-73. Wateree Development: Water quality and flow in the Wateree tailrace on July 16
demonstrating compliance with Interim Measures for Providing DO Enhancement ....................... 98
Figure 4-74. Wateree Development: Water quality and flow in the Wateree tailrace on July 24
demonstrating compliance with Interim Measures for Providing DO Enhancement ....................... 99
Figure 4-75. Wateree Development: Water quality and flow in the Wateree tailrace on July 28
demonstrating compliance with Interim Measures for Providing DO Enhancement .....................100
Figure 4-76. Wateree Development: Water quality and flow in the Wateree tailrace on July 30
demonstrating compliance with Interim Measures for Providing DO Enhancement ..................... 101
Figure 4-77. Wateree Development: Water quality and flow in the Wateree tailrace on August 3
demonstrating compliance with Interim Measures for Providing DO Enhancement .....................102
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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1 Introduction
On November 25, 2015, the Federal Energy Regulatory Commission (FERC or Commission) issued a
License to Duke Energy Carolinas, LLC (Duke Energy), for the continued operation of the Catawba-
Wateree Hydroelectric Project No. 2232 (CW Project or Project).
According to the License, Duke Energy is required to submit an annual report detailing operational
compliance with License articles during the previous year. This annual report for calendar year 2021 is
submitted in compliance with the reporting requirements, as specified in the following License
Articles.
1.1 License Article Requirements
Article — Water Quality Monitoring Plan, Paragraph (D) (License Appendix E, A-5.0)
By June 30 following each full calendar year for the term of this license, the Licensee must file
with the Commission a report verifying compliance with any applicable 401 Water Quality
Certification conditions, and must include in its filing the following information for the previous
calendar year:
(i) temperatures of water released from Project developments;
(ii) dissolved oxygen (DO) concentrations in water released from Project developments;
(iii) Minimum Continuous Flows released from the Bridgewater, Oxford, Lookout Shoals,
Wylie, and Wateree developments;
(iv) Minimum Continuous Flows released into the Great Falls Long and Short Bypassed
Reaches, and
(v) documentation of instances that the 401 Water Quality Certification requirements
were not met, along with any proposed or implemented corrective actions.
Article — Flow and Reservoir Elevation Monitoring, (License Appendix E, A-6.0)
Licensee must file with the Commission a report verifying compliance with the Normal Minimum
Elevation and Normal Maximum Elevation for Reservoir Levels, Spring Reservoir Level
Stabilization Program, Recreational Flow Releases, Minimum Continuous Flows, Minimum
Average Daily Flows, and the Wylie High Inflow Protocol, as set forth in this license. The Licensee
must include, at least, the following information for the previous calendar year:
(i) hourly flow records at Bridgewater, Oxford, Lookout Shoals, Wylie, and Wateree;
(ii) documentation of flow releases in the Catawba River Bypassed Reach, as well as the
Great Falls Long and Short Bypassed Reaches;
(iii) documentation of Recreational Flow Releases;
(iv) documentation of Minimum Continuous Flows and Minimum Average Daily Flows;
(v) hourly reservoir levels for each reservoir, along with yearly graphs showing the actual
levels throughout the calendar year; and
(vi) documentation of any instances that reservoir levels exceeded the Normal Operating
Ranges, any instances where the Spring Reservoir Level Stabilization Program
requirements or required flow releases were not met, along with any proposed or
implemented corrective actions.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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Article — Flow and Water Quality Implementation Plan, Paragraph (A) (License Appendix E, A-
2.0)
Within 180 days following the issuance of this license, the Licensee must file with the
Commission, for approval, a Flow and Water Quality Implementation Plan (FWQIP) for
completing the modifications necessary to satisfy the flow and water quality requirements at
Project developments. The Plan shall include, at a minimum:
(i) descriptions of any equipment, including flow release valves, minimum flow hydro
units, or aerating hydro units to be installed
(ii) descriptions of any proposed modifications to any Project structures to provide
prescribed flow releases or meet the requirements of the 401 Water Quality
Certifications, and
(iii) a schedule for the installations and modifications to meet the prescribed flow
releases or water quality requirements stipulated in this license.
Article — Water Quality Monitoring Plan, Paragraph (A) (License Appendix E, A-5.0)
Within 180 days following the issuance of this license, the Licensee must file with the
Commission, for approval, a Water Quality Monitoring Plan (WQMP) to monitor compliance with
water quality requirements. The plan must include, at a minimum, identification of compliance
monitoring locations and devices at applicable Project developments as needed to accurately
monitor and record flows, dissolved oxygen, and water temperatures released from Project
developments and an implementation schedule.
1.2 CRA Requirements
The Comprehensive Relicensing Agreement (CRA) filed with the FERC in 2006 included drafts of the
WQMP (Appendix F) and the FWQIP (Appendix Q. The original Water Quality Certifications (WQCs)
issued by North Carolina on November 14, 2008, and by South Carolina on February 12, 2015
(incorporated in the License as Appendices A and B, respectively) required compliance with the
following components of the CRA as a condition of certification: the Water Quality Agreements in
Section 13 of the CRA; the WQMP; and the FWQIP. Regarding compliance with the WQCs and
acknowledging that physical modifications were necessary to meet the terms of the WQCs at some
developments, the CRA Water Quality Agreements stated the following:
Subsection 13.2
Following the implementation of all flow delivery and water quality enhancement modifications
as required by the FERC-approved Flow and Water Quality Implementation Plan (FWQIP), the
Licensee shall operate the Project developments for the term of the New License in accordance
with the States' 401 Water Quality Certifications.
Subsection 13.7 Interim Procedures of the CRA
The Parties acknowledge that the Licensee shall initiate interim changes to current operation at
selected Project developments that require physical equipment additions or modifications in
accordance with the FWQIP (Appendix L). The Licensee shall initiate the Interim Measures for
Providing Aquatic Flow and/or DO Enhancement until Physical Modifications are Complete as
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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identified in the FWQIP within 60 days following the issuance of the New License and closure of
all rehearing and administrative challenge periods related to water quantity, including Project
flow releases and reservoir levels, and water quality. The interim measures will continue at each
dam or powerhouse until completion of the necessary construction at that dam or powerhouse.
Unless the Licensee is operating in accordance with the Low Inflow Protocol and/or the
Maintenance and Emergency Protocol, the Licensee shall operate the hydro units at the
powerhouses identified for Interim Measures in Appendix L in the following manner:
When the Licensee is providing flow releases, reservoir level control, and/or generation with any
of these powerhouses at times that DO in the flow release from the powerhouse would be below
401 Water Quality Certification requirements, the Licensee shall operate the available hydro
units with the greatest existing DO enhancement capability at that powerhouse in a first -on, last -
off hierarchy and shall use all the DO enhancement capability available on all hydro units that
are operated at that powerhouse if needed in its best efforts to raise DO levels.
On May 5, 2017, Duke Energy filed with the FERC an Application for Amendment of License and
Submittal of the FWQIP and WQMP. The document included revised WQCs issued by the North Carolina
Department of Environmental Quality (NCDEQ) on February 27, 2017, and the South Carolina
Department of Health and Environmental Control (SCDHEC) on April 5, 2017. The revised WQCs
incorporated by reference the revised versions of the FWQIP and WQMP. The License Amendment,
revised FWQIP, and revised WQMP were approved by the FERC on January 22, 2018. The 2021 flow and
water quality monitoring data presented in this report were collected in accordance with the 2018
License Amendment, revised FWQIP, and revised WQMP.
1.3 Status of FWQIP Physical Modifications and WQMP Requirements
in 2021
FWQIP
Among those developments identified in the FWQIP as requiring physical modifications, all Physical
Modifications Proposed to Meet Flow and/or DO Requirements were completed at the Bridgewater,
Rhodhiss, Oxford and Wylie Developments prior to 2021. These developments were required to comply
with all License and WQC requirements in 2021.
At the Great Falls -Dearborn Development, construction began on the physical modifications to allow the
release of flow into the Long and Short Bypassed Reaches in May 2021. Prior to construction, the
development was subject to compliance with the Interim Measures for Providing Aquatic Flow specified
in the FWQIP. Physical modifications to release flow are currently scheduled to be completed by spring
2023.
Physical modifications to provide aquatic flow and DO enhancement at the Wateree Development were
not complete in 2021. The Wateree Development was therefore subject to compliance with the Interim
Measures for Providing Aquatic Flow and/or DO Enhancement in 2021. Physical modifications in the
form of a new minimum flow aerating unit are currently scheduled to be completed in 2022.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
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WQMP
The United States Geological Survey (USGS) completed installation of water quality monitoring stations
in all Project tailraces in 2018. However, as noted in Table 3, Section 2.3 of the WQMP and CRA Section
13.2, compliance with water quality standards is not required until the necessary Physical Modifications
for Providing Aquatic Flow and/or DO Enhancement specified in the FWQIP have been completed.
2 Development -Specific Article Requirements
Project Development License Article requirements applicable during 2021 are detailed for each Project
Development in this section of this report. Water quality requirements for each development (water
temperature and DO) follow applicable state surface water quality standards for freshwaters.
Developments in North Carolina are required to meet standards developed by the NCDEQ (NCDEQ
2019). Developments in South Carolina follow standards developed by the SCDHEC (SCDHEC 2020).
2.1 Bridgewater Development
2.1.1 Elevation Article Requirements
The Bridgewater Development is subject to compliance with two Reservoir Elevation Articles: Reservoir
Elevation, Spring Reservoir Level Stabilization Program. The Normal Maximum Elevation compliance
limit for Lake James is 100.0 ft (local datum). The Normal Minimum Elevation compliance limit varies
seasonally as shown in Table 2-1.
Table 2-1. Bridgewater Development Normal Minimum Reservoir Elevations for Lake James.
Month
Normal Minimum Elevation (ft)
Jan
Interpolated daily, from 93.0 on Jan 1 to 92.0 on Feb 1
Feb -Mar
92.0
Apr
Interpolated daily, from 92.0 ft on Apr 1 to 95.0 on May 1
May -Sep
95.0
Oct
Interpolated daily, from 95.0 on Oct 1 to 93.0 on Nov 1
Nov -Dec
93.0
The Spring Reservoir Level Stabilization Program on Lake James began in the spring in response to four
consecutive days when lake temperatures were >_ 65 'F. The program requires lake levels to be
maintained within a range between 1.0 ft below and 2.0 ft above the lake level at the stabilization
program initiation. The stabilization program is required to last for three weeks after the program is
initiated.
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2.1.2 Flow Article Requirements
The Bridgewater Development is subject to compliance with three Flow Articles: Minimum Flows at the
Bridgewater Tailrace and in the Catawba River Bypassed Reach, Recreational Flows, Flows Supporting
Public Water Supply and Industrial Processes.
Minimum Continuous Flow compliance limits for the Bridgewater Tailrace varies seasonally, as shown in
Table 2-2.
Table 2-2. Bridgewater Development Tailrace Minimum Continuous Flow Release Requirements.
Month
Minimum Continuous Flow (cfs)
Jan -Mar
145
Apr -Jul
95
Aug -Nov
75
Dec
145
Minimum Continuous Flow compliance limits for the Bridgewater Catawba River Bypassed Reach vary
seasonally as shown in Table 2-3.
Table 2-3. Bridgewater Development Catawba River Bypassed Reach Minimum Continuous Flow
Release Requirements.
Month
Minimum Continuous Flow (cfs)
Jan -Jun
75
Jul -Nov
50
Dec
75
For the Recreational Flows Article, flows are required for float angling and paddling in accordance with
Table 2-4. Scheduled recreational flow release days are to be divided approximately equally between
flow releases to support float angling and paddling. The flows for float angling are to be as close as
feasible to 900 cfs, but shall not exceed 1,200 cfs, and the flows for paddling shall be at least 900 cfs.
Paragraph (F) of the Recreational Flows Article requires that up to 10 hours of additional recreational
flow be made available annually.
For the Flows Supporting Public Water Supply and Industrial Processes Article, at least 90 cfs Minimum
Continuous Flow is required for the City of Morganton's Catawba River Water Treatment Plant at River
Mile 264.
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Table 2-4. Bridgewater Development Recreational Flow Release Requirements.
Flow (at or above)
Dates (inclusive) Days / Description Hour Start Hour End
(cfs)
Last full weekend —
Apr 1-Apr 30
Saturday and Sunday
900
10:00 AM
3:00 PM
Each Friday, Saturday
and Sunday plus
May 1-Jul 15
Memorial and
900
10:00 AM
3:00 PM
Independence Day
Each Saturday, and
Jul 16-Aug 31
Sunday
900
10:00 AM
3:00 PM
Wednesdays and
Jun 1-Jul 31
Thursdays
900
4:30 PM
6:30 PM
Each Friday, Saturday
Sep 1-Sep 30
and Sunday plus Labor
900
10:00 AM
3:00 PM
Day
Each Saturday and
Oct 1-Oct 31
Sunday
900
10:00 AM
3:00 PM
2.1.3 Water Quality Article Requirements
The Bridgewater Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require DO and temperature monitoring at the
Bridgewater Development from April 1— November 30. Releases from the Bridgewater Development
are subject to compliance with North Carolina surface water DO and temperature standards for Class C
Mountain and Upper Piedmont waters. The North Carolina standards applicable to the Bridgewater
Development in 2021 are as follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed 29 degrees C (84.2 degrees F) for Mountain and Upper Piedmont
waters...
2.2 Rhodhiss Development
2.2.1 Elevation Article Requirements
The Rhodhiss Development is subject to compliance with one Reservoir Elevation Article: Reservoir
Elevation. Normal Minimum and Normal Maximum Elevation compliance limits for Lake Rhodhiss are as
follows:
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Normal Minimum Elevation: 94.0 ft
Normal Maximum Elevation: 100.0 ft
2.2.2 Flow Article Requirements
The Rhodhiss Development is subject to compliance with one Flow Article: Minimum Flows. The
Minimum Flows Article requires the Rhodhiss Development to release a Minimum Average Daily Flow of
225 cfs. There is no Minimum Continuous Flow release requirement.
2.2.3 Water Quality Article Requirements
The Rhodhiss Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require DO and temperature monitoring at the
Rhodhiss Development from April 1— November 30. Releases from the Rhodhiss Development are
subject to compliance with North Carolina surface water DO and temperature standards for Class C
Mountain and upper Piedmont waters. The North Carolina standards applicable to the Rhodhiss
Development in 2021 are as follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed 29 degrees C (84.2 degrees F) for Mountain and upper Piedmont
waters...
2.3 Oxford Development
2.3.1 Elevation Article Requirements
The Oxford Development is subject to compliance with one Reservoir Elevation Article: Reservoir
Elevations. Normal Minimum and Normal Maximum Elevation compliance requirements for Lake
Hickory are as follows:
Normal Minimum Elevation: 94.0 ft
Normal Maximum Elevation: 100.0 ft
2.3.2 Flow Article Requirements
The Oxford Development is subject to compliance with two Flow Articles: Recreational Flows, Minimum
Flows. For the Recreational Flows Article, the Oxford Development is subject to release flows of at least
2,600 cfs from 10:00 to 15:00 on Saturdays and Sundays from May 1 through September 30, as well as
on the first four Saturdays in October, and Memorial, Independence, and Labor Days. Paragraph (F) of
the Recreational Flows Article requires up to 10 hours of additional recreational flow be made available
annually. The Oxford Development is subject to release a Minimum Continuous Flow of 150 cfs, year-
round, to comply with the Minimum Flows Article.
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2.3.3 Water Quality Article Requirements
The Oxford Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature at the
Oxford Development from April 1— November 30. The Oxford Development is subject to compliance
with North Carolina surface water DO and temperature standards for Class C Mountain and upper
Piedmont waters. The North Carolina standards applicable to the Oxford Development in 2021 are as
follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed 29 degrees C (84.2 degrees F) for Mountain and upper Piedmont
waters...
2.4 Lookout Shoals Development
2.4.1 Elevation Article Requirements
The Lookout Shoals Development is subject to compliance with one Reservoir Elevation Article:
Reservoir Elevations. Normal Minimum and Normal Maximum Elevation compliance limits for Lookout
Shoals Lake are as follows:
Normal Minimum Elevation: 94.0 ft
Normal Maximum Elevation: 100.0 ft
2.4.2 Flow Article Requirements
The Lookout Shoals Development is subject to compliance with one Flow Article: Minimum Flows. The
Lookout Shoals Development is subject to provide a year-round Minimum Continuous Flow release of 80
cfs.
2.4.3 Water Quality Article Requirements
The Lookout Shoals Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature at the
Lookout Shoals Development from April 1— November 30. The Lookout Shoals Development is subject
to compliance with North Carolina surface water DO and temperature standards for Class C lower
Piedmont and Coastal Plain waters. The North Carolina standards applicable to the Lookout Shoals
Development in 2021 are as follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
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Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed 29 degrees C (84.2 degrees F) for lower Piedmont and Coastal Plain
waters...
2.5 Cowans Ford Development
2.5.1 Elevation Article Requirements
The Cowans Ford Development is subject to compliance with two Reservoir Elevation Articles: Reservoir
Elevations and Spring Reservoir Level Stabilization Program. The Normal Maximum Elevation
compliance limit for Lake Norman was 100.00 ft. Normal Minimum Elevation compliance limits varied
seasonally as shown on Table 2-5.
Table 2-5. Cowans Ford Normal Minimum Reservoir Elevations for Lake Norman.
Month
Normal Minimum Elevation, ft
Jan
Interpolated daily, from 93.00 on Jan 1 to 91.00 on Feb 1
Feb
Interpolated daily, from 91.00 on Feb 1 to 92.26 on Mar 1
Mar
Interpolated daily, from 92.26 on Mar 1 to 93.65 on Apr 1
Apr
Interpolated daily, from 93.65 on Apr 1 to 95.00 on May 1
May -Sep
95.00
Oct
Interpolated daily, from 95.00 on Oct 1 to 93.98 on Nov 1
Nov
Interpolated daily, from 93.98 on Nov 1 to 93.00 on Dec 1
Dec
93.00
The Spring Reservoir Level Stabilization Program on Lake Norman began in the spring in response to four
consecutive days when lake temperatures were >_ 65 °F. The program requires lake levels to be
maintained within a range between 1.0 ft below and 2.0 ft above the lake level at the stabilization
program initiation. The stabilization program is required to last for three weeks after the program is
initiated.
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2.5.2 Flow Article Requirements
The Cowans Ford Development is subject to compliance with one Flow Article: Minimum Flows. The
Cowans Ford Development is subject to provide a Minimum Average Daily Flow release of 311 cfs. There
is no Minimum Continuous Flow release requirement.
2.5.3 Water Quality Article Requirements
The Cowans Ford Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature at the
Cowans Ford Development from April 1— November 30. Releases from the Cowans Ford Development
are subject to compliance with North Carolina surface water DO and temperature standards for Class C
lower Piedmont and Coastal Plain waters when the station is generating. The North Carolina standards
applicable to the Cowans Ford Development in 2021 are as follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed... 32 degrees C (89.6 degrees F) for lower Piedmont and Coastal Plain
waters.
2.6 Mountain Island Development
2.6.1 Elevation Article Requirements
The Mountain Island Development is subject to compliance with one Reservoir Elevation Article:
Reservoir Elevations. Normal Minimum and Normal Maximum Elevation compliance limits for Mountain
Island Lake were as follows:
Normal Minimum Elevation: 94.3 ft
Normal Maximum Elevation: 100.0 ft
2.6.2 Flow Article Requirements
The Mountain Island Development is subject to compliance with one Flow Article: Minimum Flows. The
Mountain Island Development is subject to provide a Minimum Average Daily Flow release of 314 cfs.
There is no Minimum Continuous Flow release requirement.
2.6.3 Water Quality Article Requirements
The Mountain Island Development is subject to compliance with one Water Quality Article: Water
Quality Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature
at the Mountain Island Development from April 1— November 30. Releases from the Mountain Island
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Development are subject to compliance with North Carolina surface water DO and temperature
standards for Class C lower Piedmont and Coastal Plain waters when the station is generating. The
North Carolina standards applicable to the Mountain Island Development in 2021 are as follows:
North Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
North Carolina surface water temperature standard:
Temperature: not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature,
and in no case to exceed... 32 degrees C (89.6 degrees F) for lower Piedmont and Coastal Plain
waters.
2.7 Wylie Development
2.7.1 Elevation Article Requirements
The Wylie Development is subject to compliance with two Reservoir Elevation Articles: Reservoir
Elevations, Spring Reservoir Level Stabilization Program. Normal Minimum and Maximum Elevation
compliance limits for Lake Wylie are as follows:
Normal Minimum Elevation: 94.0 ft
Normal Maximum Elevation: 100.0 ft
The Spring Reservoir Level Stabilization Program on Lake Wylie began in the spring in response to four
consecutive days when lake temperatures were >_ 65 'F. The program requires lake levels to be
maintained within a range between 1.0 ft below and 2.0 ft above the lake level at the stabilization
program initiation. The stabilization program is required to last for three weeks after the program is
initiated.
2.7.2 Flow Article Requirements
The Wylie Development is subject to compliance with four Flow Articles: Recreational Flows, Minimum
Flows, Wylie High Inflow Protocol, and Flows Supporting Public Water Supply and Industrial Processes.
Recreational flow requirements for the Wylie Development are set forth in accordance with the Table 2-
6.
Paragraph (F) of the Recreational Flows Article requires that up to 10 hours of additional recreational
flow be made available annually. The Wylie Development is also subject to a pre -recreational flow of at
least 1,300 cfs for six hours prior to recreational releases scheduled May 1 through July 15 to ensure
suitable water levels at Landsford Canal State Park.
The Wylie Development is subject to provide a year-round Minimum Continuous Flow of 1,100 cfs, apart
from times when the High Inflow Protocol is in effect. If the High Inflow Protocol is in effect, the Wylie
Development is required to provide a Minimum Continuous Flow of 1,300 cfs from February 15 through
May 15. The High Inflow Protocol was in effect in 2021 from February 15 through May 15.
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Table 2-6. Wylie Development Recreational Flow Release Requirements.
Dates Flow (at or above)
(inclusive) Days /Description Hour Start Hour End
(cfs)
Last full weekend —
Apr 1-Apr 30
Saturday and Sunday
3,000
10:00 AM
4:00 PM
Each Friday, Saturday
May 1-Jun 1S
and Sunday plus
3,000
10:00 AM
4:00 PM
Memorial Day
Each Friday, Saturday
Jun 16-Jul 15
and Sunday plus
3,000
10:00 AM
4:00 PM
Independence Day
Each Saturday and
Jul 16- Aug 31
Sunday
3,000
10:00 AM
4:00 PM
Each Friday, Saturday
Sep 1 - Sep 30
and Sunday plus Labor
3,000
10:00 AM
4:00 PM
Day
Each Saturday and
Oct 1-Oct 31
Sunday
3,000
10:00 AM
4:00 PM
The Wylie Development is subject to compliance with the Flows Supporting Public Water Supply and
Industrial Processes Article, Paragraph (A), Part 2, as follows:
i. At River Mile 120, at least 600 cfs continuous minimum flow and approximately 1,000 cfs
for a continuous 16-hour period each day for the Bowater Pulp and Paper Mill'.
ii. At River Mile 122, up to an additional 71 cfs above existing flows in the river (as
measured at United Sates Geological Survey (USGS) Gage #02147000, Catawba River
near Catawba, SC) during periods of low river flow, the day after the Licensee receives a
request from the Union/Lancaster Catawba River Water Treatment Plant, to allow this
entity to operate within its permit (PERMIT NO. (P/N) 29 WS01 S02) issued by the South
Carolina Department of Health and Environmental Control.
iii. At USGS Gage #02146000 (Catawba River near Rock Hill, SC) (River Mile 137.6), at least
619 cfs weekly average flow to avoid pumping restrictions at Charlotte -Mecklenburg
Utilities' Mountain Island Development raw -water pumping facility imposed by
Condition (B) of the Commission's Order Approving Non -Project Use of Lands, February
23, 2004 (106 FERC 62,151) until such time that the Commission removes those
restrictions by a subsequent order.
iv. The above flow releases from the Wylie Development also meet the flow needs of the
Rock Hill (SC) Municipal back-up water supply intake (River Mile 137), Celanese Acetate's
intake (River Mile 136), and Nations Ford Chemical's intake (River Mile 135).
1 now New-Indy Catawba, LLC
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2.7.3 Water Quality Article Requirements
The Wylie Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature at the
Wylie Development from April 1— November 30. Releases from the Wylie Development are subject to
compliance with South Carolina surface water DO and temperature standards. The South Carolina
standards applicable to the Wylie Development in 2021 are as follows:
South Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
South Carolina temperature standard:
The water temperature of all Freshwaters which are free flowing shall not be increased more
than SoF [sic] (2.8°C) above natural temperature conditions and shall not exceed a maximum of
90°F (32.2°C) as a result of the discharge of heated liquids unless a different site -specific
temperature standard as provided for in C.12. has been established, a mixing zone as provided in
C.10. has been established, or a Section 316(a) determination under the Federal Clean Water Act
has been completed.
2.8 Fishing Creek Development
2.8.1 Elevation Article Requirements
The Fishing Creek Development is required to comply with one Reservoir Elevation Article: Reservoir
Elevations. Normal Minimum and Maximum Elevation compliance limits for Fishing Creek Reservoir are
as follows:
Normal Minimum Elevation: 95.0 ft
Normal Maximum Elevation: 100.0 ft
2.8.2 Flow Article Requirements
The Fishing Creek Development is subject to compliance with one Flow Article: Minimum Flows. The
Minimum Flows Article requires the Fishing Creek Development to release a Minimum Average Daily
Flow of 440 cfs. There is no Minimum Continuous Flow release requirement.
2.8.3 Water Quality Article Requirements
The Fishing Creek Development is subject to compliance with one Water Quality Article: Water Quality
Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require DO and temperature monitoring at the
Fishing Creek Development from April 1— November 30. Releases from the Fishing Creek Development
are subject to compliance with South Carolina surface water DO and temperature standards when the
station is generating. The South Carolina standards applicable to the Fishing Creek Development in 2021
are as follows:
South Carolina surface water DO standards:
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Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
South Carolina temperature standard:
The water temperature of all Freshwaters which are free flowing shall not be increased more
than SoF [sic] (2.8°C) above natural temperature conditions and shall not exceed a maximum of
90°F (32.2°C) as a result of the discharge of heated liquids unless a different site -specific
temperature standard as provided for in C.12. has been established, a mixing zone as provided in
C.10. has been established, or a Section 316(a) determination under the Federal Clean Water Act
has been completed.
2.9 Great Falls -Dearborn Development
2.9.1 Elevation Article Requirements
The Great Falls -Dearborn Development is subject to compliance with one Reservoir Elevation Article:
Reservoir Elevations. Normal Minimum and Maximum Elevation compliance limits for Great Falls
Reservoir are as follows:
Normal Minimum Elevation: 95.0 ft
Normal Maximum Elevation: 100.0 ft
2.9.2 Flow Article Requirements
The Great Falls and Dearborn Hydroelectric Stations were not subject to compliance with any Flow
Articles in 2022. However, Dearborn Hydro generation flow data were used in conjunction with
assessment of compliance with water quality standards in the Great Falls -Dearborn tailrace.
Until structural modifications are complete, the Great Falls -Dearborn Development is required to
comply with the Interim Measures for Providing Aquatic Flow specified in the FWQIP, as follows:
In order to provide aquatic flow to the Short Bypass Duke Energy will leave open the existing
trash gate continuously with the exception of any time if and when it must be closed for public
safety, operational emergency, to perform design reconnaissance for the permanent headworks
modifications, or to begin constructing the permanent modifications.
2.9.3 Water Quality Article Requirements
The Great Falls -Dearborn Development is subject to compliance with one Water Quality Article: Water
Quality Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and temperature
at the Great Falls -Dearborn Development from April 1— November 30. Releases from the Great Falls -
Dearborn Development are subject to compliance with South Carolina surface water DO and
temperature standards for freshwaters when the station is generating. The South Carolina standards
applicable to the Great Falls -Dearborn Development in 2021 are as follows:
South Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
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Daily Average DO: >_ 5.0 mg/L
South Carolina temperature standard:
The water temperature of all Freshwaters which are free flowing shall not be increased more
than SoF [sic] (2.8°C) above natural temperature conditions and shall not exceed a maximum of
90°F (32.2°C) as a result of the discharge of heated liquids unless a different site -specific
temperature standard as provided for in C.12. has been established, a mixing zone as provided in
C.10. has been established, or a Section 316(a) determination under the Federal Clean Water Act
has been completed.
2.10 Rocky Creek -Cedar Creek Development
2.10.1 Elevation Article Requirements
The Rocky Creek -Cedar Creek Development is subject to compliance with one Reservoir Elevation
Article: Reservoir Elevations. Normal Minimum and Maximum Elevation compliance limits for Cedar
Creek Reservoir are as follows:
Normal Minimum Elevation: 96.0 ft
Normal Maximum Elevation: 100.0 ft
2.10.2 Flow Article Requirements
The Rocky Creek -Cedar Creek Development is subject to compliance with one Flow Article: Minimum
Flows. The Rocky Creek -Cedar Creek Development is required to release a Minimum Average Daily Flow
of 445 cfs. There is no Continuous Minimum Flow release requirement. All eight units at the Rocky
Creek Hydro Station have been decommissioned, therefore all flows released from the Rocky Creek -
Cedar Creek Development were provided via Cedar Creek operation.
2.10.3 Water Quality Article Requirements
The Rocky Creek -Cedar Creek Development was subject to compliance with one Water Quality Article:
Water Quality Monitoring Plan. Sections 2.3 and 2.4 of the WQMP require monitoring of DO and
temperature at the Rocky Creek -Cedar Creek Development from April 1— November 30. Releases from
the Rocky Creek -Cedar Creek Development are subject to compliance with SCDHEC surface water DO
and temperature standards for freshwaters when the station is generating. The South Carolina
standards applicable to the Rocky Creek -Cedar Creek Development in 2021 are as follows:
South Carolina surface water DO standards:
Instantaneous DO: >_ 4.0 mg/L
Daily Average DO: >_ 5.0 mg/L
South Carolina temperature standard:
The water temperature of all Freshwaters which are free flowing shall not be increased more
than SoF [sic] (2.8°C) above natural temperature conditions and shall not exceed a maximum of
90°F (32.2°C) as a result of the discharge of heated liquids unless a different site -specific
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temperature standard as provided for in C.12. has been established, a mixing zone as provided in
C.10. has been established, or a Section 316(a) determination under the Federal Clean Water Act
has been completed.
2.11 Wateree Development
2.11.1 Elevation Article Requirements
The Wateree Development is subject to compliance with two Reservoir Elevation Articles: Reservoir
Elevations, Spring Reservoir Level Stabilization Program. The Normal Maximum Elevation compliance
limit for Lake Wateree was 100.0 ft. Normal Minimum Elevation compliance limits vary seasonally as
shown on Table 2-7.
Table 2-7. Wateree Development Normal Minimum Reservoir Elevations for Lake Wateree.
Month
Normal Minimum Elevation, ft
Jan
93.0
Feb
Interpolated daily, from 93.0 ft on Feb 1 to 94.0 ft on Mar 1
Mar -Sep
94.0
Oct
Interpolated daily, from 94.0 ft on Oct 1 to 93.0 ft on May 1
Nov -Dec
93.00
The Spring Reservoir Level Stabilization Program on Lake Wateree began in the spring in response to
four consecutive days when lake temperatures were > 6S 'F. The program requires lake levels to be
maintained within a range between 1.0 ft below and 2.0 ft above the lake level at the stabilization
program initiation. The stabilization program is required to last for three weeks after the program is
initiated.
2.11.2 Flow Article Requirements
The Wateree Development is subject to compliance with two Flow Articles: Recreational Flows, Flows
Supporting Public Water Supply and Industrial Processes. Following commissioning of the new
minimum flow aerating hydro unit at Wateree, the Wateree Development will also be required to
comply with the Minimum Continuous Flows Article. Commissioning of the new unit is currently
scheduled to be completed in 2022. Until commissioning of the new unit is complete, in lieu of
compliance with the Minimum Continuous Flows Article, the Wateree Development is required to
comply with the Interim Measures for Providing Aquatic Flow specified in the FWQIP.
In lieu of the Minimum Flows Article, the Wateree Development is required to comply with the following
Interim Measures for Providing Aquatic Flow specified in the FWQIP:
...approximate minimum continuous flows by (1) pulsing an existing unit 1 hr on, 2 hrs off from
May 16 thru Feb 14 during periods when at least 1 unit is not running continuously and (2)
running an existing hydro unit continuously from Feb 15 thru May 15.
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For the purpose of assessing compliance with the generation patterns mandated by the Interim
Measures, the Wateree Development is defined as generating when discharge flows equal or exceed
500 cfs.
The Wateree Development is subject to release flows required by the Flows Supporting Public Water
Supply and Industrial Processes Article as follows:
At least 800 cfs continuous minimum flow at River Mile 12 for the South Carolina Electric & Gas
Company's [now Dominion Energy South Carolina] Wateree Steam Station and also for the
International Paper facility at River Mile 17.
The Recreational Flows Article requires the Wateree Development to release at least 2,760 cfs from
10:00 to 15:00 on scheduled recreational release dates, April through July, and September through
October. Paragraph (F) of the Recreational Flows Article requires up to 10 hours of additional
recreational flow be made available annually.
2.11.3 Water Quality Article Requirements
The FWQIP requires the replacement of one existing hydro unit with a smaller unit with aerating
capability (Physical Modifications Proposed to Meet Flow and/or DO Requirements at the Wateree
Development). This physical modification was not complete in 2021. Therefore, the Wateree
Development was not required to comply with SCDHEC water quality standards in the Wateree Tailrace
during the water quality monitoring season of 2021, as stated in Table 3 of Section 2.3 of the WQMP:
At several locations, the installation of water quality monitors will precede the installation of the
equipment modifications necessary to achieve compliance. In these cases, the monitors will
assist Duke Energy in the implementation of interim measures per the FWQIP. However, these
monitor results are not suitable for compliance assessments until the necessary equipment
modifications have been implemented (refer to CRA Section 13.2).
The FWQIP requires an interim measure for operations until the aerating unit installation is completed:
When DO is below state standards, operate existing units with auto -venting capability (Units 1
and 3) on a first -on, last off hierarchy whenever the station is being operated for flow release,
reservoir level control or generation.
3 Methods
3.1 Reservoir Elevation Article Compliance Assessment
Duke Energy recorded reservoir surface elevations hourly at all Catawba-Wateree Project Developments
in 2021. Reservoir elevations were expressed in feet, relative to a full pond elevation defined for each
reservoir as 100 ft (local datum). Reservoir surface elevations and interpolated daily Normal Minimum
Elevation compliance limits were rounded to the nearest 0.1 ft prior to assessing compliance, except for
the Cowans Ford Development (Lake Norman), where observed elevations and interpolated Normal
23

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Minimum Elevation compliance limits were rounded to the nearest 0.01 ft to allow for consistency with
compliance elevations listed for Lake Norman in the License.
Lake elevation data are presented graphically by development for visual comparison against specific
Reservoir Elevation Article requirements. If any deviations from Reservoir Elevation Articles in 2021
were not previously reported to the FERC, then a brief summary of the deviation can be found in the
development -specific Reservoir Elevation Article results section (Section 4). Hourly elevation data for
each development are provided in a Microsoft Excel spreadsheet as Appendix A-1 to this report.
3.2 Flow Article Compliance Assessment
Two sources of flow data were utilized to assess compliance with the Flow Articles: flows recorded at
USGS Gaging Stations located in the development tailraces or downstream, and development flow
releases calculated by Duke Energy based on generation, spill flow, and leakage data.
Flow data are expressed as cubic feet per second (cfs). Flow data were rounded to the nearest 1 cfs for
purposes of reporting and assessing compliance. All USGS flow data used in compliance assessment
were classified by the USGS as 'Approved' or'Approved: estimated'. All flow data calculated by Duke
Energy from generation, spill flow, and leakage data were reported from an internal Duke Energy
automated software system and validated prior to analysis.
The Licensee complied with Paragraph (H) of the Recreational Flows Article by holding the Catawba-
Wateree Annual Recreational Flow Schedule Planning Meeting on March 29, 2021. The Summary of the
meeting was communicated to the FERC on April 26, 2021. The specific recreational flow release
schedule set forth in the Summary of the Annual Meeting constituted Recreational Flows Article
compliance requirements for 2021.
Flow data supporting Flow Article compliance determinations are presented graphically by development
for visual comparison against specific Flow Article compliance limits. A summary of the 2021 Flow
Article deviations previously communicated to the FERC for the Catawba-Wateree Project Developments
are listed in Table 4-2. If deviations from Flow Articles in 2021 were not previously reported to the
FERC, then a brief summary of the deviation can be found in the development -specific Flow Article
results section.
The USGS data recorded in 15-minute increments from all gages as well as data from generation records
is provided in a Microsoft Excel spreadsheet as Appendix B-1 to the report. Summaries of the flow data
as well as the compliance requirements is provided in another Microsoft Excel spreadsheet as
Appendices C-1 to this report.
3.3 Water Quality Compliance Assessment
Instantaneous water quality (temperature and DO) measurements were recorded at 15-minute intervals
from April 1 through November 30, 2021 at monitoring stations in each development tailrace or
downstream. These stations were installed, operated, and maintained by the USGS. Associated data
were reviewed for accuracy according to USGS Quality Assurance protocols. Data classified as
"Approved" by the USGS were used for assessment against applicable state water quality standards.
The Wateree Development was the exception as physical modifications, as required by the FWQIP, were
not complete in 2021. Therefore, 2021 water quality data were not reported for the Wateree
24

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Development. In lieu of compliance with water quality standards from April 1 through November 30,
the Wateree Development was subject to compliance with the Interim Measures for Providing DO
Enhancement specified in the FWQIP. Deviations from water quality standards were assessed at each
development. At developments not required to release a Minimum Continuous Flow, only water quality
values recorded while the station was generating or releasing spill flow were assessed for deviations.
Developments were defined as generating or releasing flow when flow was >_ 300 cfs, except for the
Wateree Development where generating or releasing flow was defined when flow was >_ 500 cfs. For
developments not required to release a Minimum Continuous Flow, deviations from the applicable Daily
Average and Instantaneous DO standard were assessed using DO concentrations recorded while the
station was generating or releasing flow.
Results of 2021 water quality compliance assessments are summarized for all the Catawba-Wateree
Project Developments in Table 4-3. Specific deviations from Instantaneous and Daily Average DO
standards are discussed in the development -specific Water Quality Article results section.
Compliance with water quality standards, and/or with Interim Measures for DO Enhancement where
applicable, is assessed for individual developments in the Water Quality Article results section, including
documentation of deviations from water quality standards and interim measures. Water quality data
recorded at 15-minute intervals are provided in a Microsoft Excel spreadsheet as Appendix D-1 to this
report.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4 Results and Discussion
4.1 Elevation Article Compliance
The FERC was notified of deviations from Reservoir Elevation Article compliance throughout the year for
each of the developments. Table 4-1 summarizes 2021 Reservoir Elevation Article deviations for all
developments including dates the deviations were communicated to the FERC.
Reservoir elevation data related to Reservoir Elevation Article compliance are presented graphically by
development for visual comparison against Reservoir Elevation Article requirements. Specific numeric
compliance limits are indicated in the Development -specific Article Requirement section of this report.
Table 4-1. Summary of Reservoir Elevation Article Deviations in 2021 and Dates of FERC Notification.
Date Development Summary of Notification
12/15/2020
Great Falls/Dearborn
Advance Notification of Reservoir Level Deviation;
trial drawdown from Jan 4-25, 2021
2/19/2021
Great Falls/Dearborn
Notification of Reservoir Level Deviations due to
high inflow event
2/26/2021
Lookout Shoals and Wateree
Lake Level Returning to the Normal Operating Range
3/31/2021
Rhodhiss, Oxford, Lookout
Notification of Reservoir Level Deviations due to
Shoals, Mountain Island,
high inflow event
Wateree
4/7/2021
Rhodhiss, Oxford, Lookout
Lake Levels Returning to the Normal Operating
Shoals, Mountain Island,
Range
Wateree
5/25/2021
Great Falls/Dearborn
Request for approval of extended Great Falls
Reservoir drawdown
7/27/2021
Great Falls/Dearborn
Advanced notification of drawdown 1 ft below
normal minimum for < 30 days
8/10/2021
Great Falls/Dearborn
FERC-approved Reservoir Level Deviation
8/23/2021
Rhodhiss
Notification of Reservoir Level Deviation
10/8/2021
Great Falls/Dearborn
Notice of deviation on 10/6/2021 - level below lake
level variance approved by FERC on 8/10/2021
10/12/2021
Bridgewater, Rhodhiss, Oxford,
Notification of Reservoir Level Deviations and
Lookout Shoals
Recreation Flow Impacts due to high inflow event
26

2021 Catawba-Wateree Hydroelectric Project Compliance Report
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4.1.1 Bridgewater Development
Lake James hourly surface elevations for January 1-December 31, 2021 are summarized in Figure 4-1.
There were no deviations from Reservoir Elevation Articles at the Bridgewater Development in 2021.
102
—
100
C
l6
98
m
U
°
m 96
C
° 94
a
w 92
90 -4-
Jan
Lake James Hourly Lake Elevation
�4-- Spring Reservoir Level Stabilization Program:
April 22 - Mav 12
- J _ _ _ n
-.., 1-4-
i
r ;
Feb Mar Apr May Jun Jul Aug Sep act Nov Dec
Lake Elevation — — - Normal Minimum — — — Normal Maximum
Figure 4-1. Bridgewater Development: Lake James Hourly Surface Elevations, January 1-December 31,
2021.
27

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.2 Rhodhiss Development
Lake Rhodhiss hourly surface elevations for January 1-December 31, 2021 are summarized in Figure 4-2.
Reservoir Elevation Article deviations for the Rhodhiss Development are listed in Table 4-1. Deviations
and associated explanations were reported to the FERC following deviation occurrence.
MIMS
--- 102
E
100
0
aD 98
a�
0 96
ro
aD
w 94
92 +
Jan
Lake Rhodhiss Hourly Lake Elevation
Feb Mar Apr May Jun Jul Aug Sep ❑ct Nov Dec
Lake Elevation — — Normal Minimum — — — Normal Maximum
Figure 4-2. Rhodhiss Development: Lake Rhodhiss Hourly Surface Elevations, January 1-December 31,
2021.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.3 Oxford Development
Lake Hickory (Oxford) hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-3. The Reservoir Elevation Article deviation for the Oxford Development shown in Figure 4-3 is
listed in Table 4-1. The deviation and associated explanation were reported to the FERC following the
deviation occurrence.
101
100
99
c�
98
U
O
97
m
96
0
cU
> 95
W
Lake Hickory Hourly Lake Elevation
94 — — — — — — — — — — — — — — — — — — — — — — -
93
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation Normal Minimum — Normal Maximum
Figure 4-3. Oxford Development: Lake Hickory Hourly Surface Elevations, January 1-December 31,
2021.
29

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.4 Lookout Shoals Development
Lookout Shoals Lake hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-4. Reservoir Elevation Article deviations for the Lookout Shoals Development are listed in Table
4-1. Deviations and reasons for the deviation were previously reported to the FERC.
Lookout Shoals Hourly Lake Elevation
104
102
E
D
co
100
U
O
98
c
96
c�
a�
uJ 94
92
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation Normal Minimum — Normal Maximum
Figure 4-4. Lookout Shoals Development: Lookout Shoals Lake Hourly Surface Elevations, January 1-
December 31, 2021.
30

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.5 Cowans Ford Development
Lake Norman (Cowans Ford) hourly surface elevations for January 1-December 31, 2021 are summarized
in Figure 4-5. There were no deviations from Reservoir Elevation Articles at the Cowans Ford
Development in 2021.
102
100
1=
Lake Norman Hourly Lake Elevation
Spring Reservoir Level Stabilization Program:
April 22 - May 12
— — — — — — — — L — J — — — — — — — — — — — — — — — — — — --
x.
{
90
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation — — Normal Minimum --- Normal Maximum
Figure 4-5. Cowans Ford Development: Lake Norman Hourly Surface Elevations, January 1-December
31, 2021.
31

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.6 Mountain Island Development
Mountain Island Lake hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-6. Reservoir Elevation Article deviations for the Mountain Island Development are listed in
Table 4-1. Deviations and associated explanations were reported to the FERC following the deviation
occurrence.
Mountain Island Lake Hourly Lake Elevation
102
E 100
S
cU
0 98
0
a�
a�
96
0
S
c�
a) W 94
92
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation Normal Minimum — Normal Maximum
Figure 4-6. Mountain Island Development: Mountain Island Lake Hourly Surface Elevations, January 1-
December 31, 2021.
32

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.7 Wylie Development
Lake Wylie hourly surface elevations for January 1-December 31, 2021 are summarized in Figure 4-7.
There were no deviations from Reservoir Elevation Articles at the Wylie Development in 2021.
101
100
99
98
0
97
c 96
0
(D 95
w
94
93
Jan
Lake Wylie Hourly Lake Elevation
Spring Reservoir Level Stabilization Program-
April 21 - Nlay 11
— — — — — — —h — — — — — — — — — — — — — — — — — — —
Il
Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation -- Normal Minimum — — — Normal Maximum
Figure 4-7. Wylie Development: Lake Wylie Hourly Surface Elevations, January 1-December 31, 2021.
33

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.8 Fishing Creek Development
Fishing Creek Reservoir hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-8. There were no deviations from Reservoir Elevation Articles at the Fishing Creek
Development in 2021.
101
_ 100
E
99
6 98
m
97
c
0
96
a�
W
95
94 +
Jan
Fishing Creek Reservoir Hourly Lake Elevation
Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation Normal Minimum — Normal Maximum
Figure 4-8. Fishing Creek Development: Fishing Creek Reservoir Hourly Surface Elevations, January 1-
December 31, 2021.
34

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.9 Great Falls -Dearborn Development
Great Falls Reservoir hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-9. Reservoir Elevation Article deviations for the Great Falls -Dearborn Development are listed in
Table 4-1. Deviations and associated explanations were reported to the FERC following deviation
occurrence.
Great Falls Reservoir Hourly Elevation
102
100
E 98
c�
96
U
0 94
92
c
90
c�
0 88
W
86 � I � � l�■
84
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Level Normal Minimum — Normal Maximum
Figure 4-9. Great Falls -Dearborn Development: Great Falls Reservoir Hourly Surface Elevations,
January 1-December 31, 2021.
35

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.10 Rocky Creek -Cedar Creek Development
Cedar Creek Reservoir hourly surface elevations for January 1-December 31, 2021 are summarized in
Figure 4-10. The reservoir elevation deviations on January 11, 2021 from 16:00 to January 12 at 07:00
and February 17 from 0:00 to February 17, 2021 at 09:00 were due to incidental maintenance activities
at the hydro station and did not require previous reporting to the FERC.
Incidental Maintenance is defined in the License's Maintenance and Emergency Protocol (MEP) as
maintenance of hydro project works that does not require deviation from any License conditions related
to prescribed flow releases from Project structures, or the Normal Operating Ranges for reservoir levels,
or is less than 24 hours in duration and will not require any excursions below any Critical Flows or
Critical Reservoir Elevations.
Cedar Creek Reservoir Hourly Elevation
102
101
E
D
CU 100
0 99
a�
98
c
0
97
LU
96
95
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lake Elevation Normal Minimum — Normal Maximum
Figure 4-10. Rocky Creek -Cedar Creek Development: Cedar Creek Reservoir Hourly Surface Elevations,
January 1-December 31, 2021.
36

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.1.11 Wateree Development
Lake Wateree hourly surface elevations for January 1-December 31, 2021 are summarized in Figure 4-
11. Reservoir Elevation Article deviations for the Wateree Development are listed in Table 4-1.
Deviations and associated explanations were reported to the FERC following deviation occurrence.
104
102
3
100
O
98
da
e
0 96
a�
w 94
92
Lake Wateree Hourly Lake Elevation
Spring Reservoir Level Stabilization Program:
April 15 - May 5
--- -- —I
r ti
Jan Feb Mar Apr Mav Jun Jul Aug Sep Oct Nov Dec
Lake Elevation — — Normal Minimum --- Normal Maximum
Figure 4-11. Wateree Development: Lake Wateree Hourly Surface Elevations, January 1-December 31,
2021.
4.2 Flow Article Compliance
The FERC was notified when deviations from Flow Article requirements occurred throughout the year
for each of the developments. Table 4-2 summarizes 2021 Flow Article deviations including dates of
FERC notification.
Flow data and compliance limits are presented graphically by development. Specific numeric
compliance limits are indicated in the Development -Specific Article Requirement section (Section 2) of
this report.
37

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Table 4-2. Summary of Flow Article Deviations in 2021 and Dates of FERC Notification.
Notification Date
Development
Summary of Notification
Advance Notification of MEP Conditions A.1 and B.1 for
1/13/2021
Rhodhiss
Rhodhiss Development and Request for Commission Approval
of Temporary License Variance
3/15/2021
Rhodhiss
FERC Order Granting Temporary Variance of Reservoir
Elevation and Minimum Average Daily Flow Requirement
5/26/2021
Bridgewater
Modification in Recreation Flow Releases due to Special River
Access on 5/22 and 5/23/2021
6/1/2021
Bridgewater
Recreation Flow Deviation due to stranded boater on
5/30/2021
7/8/2021
Oxford
Recreation flow deviation due to water rescue on 7/3/2021
8/6/2021
Lookout Shoals
Notification of Minimum Continuous Flow deviation thought
to be due to faulty gage
8/17/2021
Lookout Shoals
Follow-up notification of no deviation (due to calibrated USGS
gage)
Notice of minimum flow deviations (interim measures) due to
9/2/2021
Wateree
unplanned station outage on 8/31/2021 to repair raw water
line
10/6/2021
Bridgewater
Recreation Flow Deviation due to stranded boater on
10/3/2021
10/14/2021
Lookout Shoals
Advanced notice of Minimum Continuous Flow deviation due
to 44 kv line station outage on 10/21 - 11/12/2021
11/17/2021
Lookout Shoals
Follow-up report of Minimum Continuous Flow deviations
from 10/21-11/25 station outage
11/29/2021
Bridgewater
FERC acknowledgement of 10/6/2021 notification
38

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.1 Bridgewater Development
Bridgewater Development continuous flows are summarized in Figures 4-12 through 4-14. There were
no deviations from Minimum Continuous Flow requirements at the Bridgewater Development in 2021.
10000
1000
U
u_ 100
10 4-
1/1/21
Bridgewater 2021 Continuous Flows
3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21
Actual Flow Minimum Continuous Flow Requirement
1 /1 /22
Figure 4-12. Bridgewater Development: Flows measured in the Bridgewater Hydroelectric Station
tailrace at USGS Gaging Station 02138520, January 1-December 31, 2021.
120
100
46
U
0 80
L.L
60
40
1/1/21
Catawba River Bypassed Reach Continuous Flows
3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21
Actual Flow Minimum Continuous Flow Requirement
1 /1 /22
Figure 4-13. Bridgewater Development: Flows measured in the Bridgewater Catawba River Bypassed
Reach at USGS Gaging Station 02138816, January 1-December 31, 2021.
39

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
120
- 100
U
0 80
LL
60
40 4-
6/1 /21
Catawba River Bypassed Reach June - July 2021 Flows
7/1 /21
Actual Flow Minimum Continous Flow Requirement
8/1 /21
Figure 4-14. Bridgewater Development: The figure above is excerpted from Figure 4-13 for closer
examination.
Bridgewater Development Flows for Supporting Public Water Supply and Industrial Processes are
summarized in Figure 4-15. There were no deviations from Flows for Supporting Public Water Supply
and Industrial Processes at the Bridgewater Development in 2021.
10000
1000
U
LL 100
10 4-
1/1/21
Flows Supporting Public Water Supply and Industrial Processes
3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21 1 /1 /22
Actual Flow Minimum Flow Requirement
Figure 4-15. Bridgewater Development: Total flow released from the Bridgewater Development (sum
of Bridgewater Hydro tailrace and Catawba River Bypassed Reach flows), January 1-December 31,
2021, to support Public Water Supply and Industrial Processes Article.
40

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Recreation angling flow deviations reported to FERC are listed in Table 4-2. Replacement flow for May
23 was added to the end of the paddling flow period on this date after flows were lowered for a paddler
rescue. Replacement flow for high inflow on October 10 was provided on October 18 (Figure 4-16).
Bridgewater 2021 Recreation Angling Flows
3200
3100
3000
1400
46 1200
0 1000 If lit t i (�i! �t ! �t X W* X X
800 - - - - - - - -- ---------- —
ILL
600
400
x
200 x
0
4/1 /21 6/1 /21 8/1 /21 10/1 /21
x Actual Flow Minimum Flow Requirement Maximum Flow Requirement
Figure 4-16. Bridgewater Development: Recreational flows released for the purpose of float angling,
April -October 2021. Flows were measured at USGS Gaging Station 02138520.
41

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Recreation paddling flow deviations reported to FERC are documented in Table 4-2. Replacement flow
for May 22, May 30, and October 3 was added to the end of the paddling flow period on these dates
after flows were lowered for paddler rescues. Although not required, replacement flow for high inflow
on October 9 was provided on October 28 (Figure 4-17).
3200
K]tell]
3000 J'
_ 2000
1800
1600
_p 1400
LL 1200
1000
800
600
400
200
0
4/ 1 /21
Bridgewater 2021 Recreation Paddling Flows
x x x x0c x**Pik*>**xk*xx>N x X x X W x x X
6/1 /21
8/1 /21
x Actual Flow Minimum Flow Requirement
0
X
`UlkF AI
Figure 4-17. Bridgewater Development: Recreational flows released for the purpose of paddling, April -
October 2021. Flows were measured at USGS Gaging Station 02138520.
42

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Migratory bird hunting flows provided October 21-24 are summarized in Figure 4-18. These flows
demonstrate Bridgewater Development compliance with the Recreational Flows Article by providing up
to an additional 10 hours of recreational flows upon request.
3000
2500
2000
U
1500
0
LL
1000
500
0
10/21 /21
Bridgewater 2021 Migratory Bird Hunting Flows
10/22/21
10/23/21
Target Flow (not a compliance limit)
10/24/21
Figure 4-18. Bridgewater Development: Recreational flows released for the purpose of migratory bird
hunting, October 21-23, 2021. Flows were measured at USGS Gaging Station 02138520. See Annual
Recreation Planning Meeting 2018, FERC Accession No. 20180424-5136.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.2 Rhodhiss Development
Average daily flows for the Rhodhiss Development are summarized in Figure 4-19. A License variance
for deviation from the weekly Minimum Average Daily Flow requirement beginning in December 2021
was approved by FERC on March 15, 2021 (see Table 4-2).
Rhodhiss 2021 Average Daily Flows
10000
0 1000
0
u_
100
10
1 /1 /21 3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21 1 /1 /22
Average Flow Minimum Average Daily Flow Requirement
Figure 4-19. Rhodhiss Development: Average daily flows released at the Rhodhiss Development
January 1-December 31, 2021.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.3 Oxford Development
Oxford Development continuous flows are summarized in Figure 4-20. There were no deviations from
Minimum Continuous Flow requirements at the Oxford Development in 2021.
L
u_
Oxford 2021 Continuous Flows
10000
1000
100
10
1 /1 /21 3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21 111122
Actual Flow Minimum Continuous Flow Requirement
Figure 4-20. Oxford Development: Flows measured at USGS Gaging Station 0214196125 in the Oxford
tailrace, January 1-December 31, 2021.
Recreational flows for the Oxford Development are summarized in Figure 4-21 and deviations reported
to the FERC are listed in Table 4-2. Replacement flow for July 3 was added to the end of the paddling
flow period on the same day after flows were lowered for a paddler rescue. Although not required,
replacement flow for high inflow on August 21, August 22, and October 9 was provided on August 27,
September 10, and October 10.
No official request for additional recreational flow releases was received for the Oxford Development,
but an additional 10 hours of recreational flow releases were provided in 2021.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
8000
7000
6000
5000
U
4000
3000
2000
1000
0
5/1 /21
Oxford 2021 Recreational Flows
X
X NK MK 0 A %K ANC Xx 0 * %K x %R X
x
7/1 /21
�K*M%K*X
9/1 /21
x Actual Flow Minimum Required Flow
Figure 4-21. Oxford Development: Recreational flows measured at USGS Gaging Station 0214196125
in the Oxford tailrace, May -October 2021.
4.2.4 Lookout Shoals Development
Lookout Shoals Development continuous flows are summarized in Figure 4-22. There were two
Minimum Continuous Flow deviations in 2021 (see Figure 4-23). Notification of the Minimum
Continuous Flow deviations were provided to FERC as listed in Table 4-2.
10000
U 1000
3
0
LL
100
10
1/1/21
Lookout Shoals 2021 Continuous Flows
3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21
Actual Flow Minimum Continuous Flow Requirement
1/1/22
Figure 4-22. Lookout Shoals Development: Flows measured at USGS Gaging Station 0214244102 in the
Lookout Shoals tailrace, January 1-December 31, 2021.
46

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
IL
10000
1000
100
10
Lookout Shoals 2021 Continuous Flows October 15 - November 15, 2021
10/18/21 10/25/21 11 /1 /21 11 /8/21 11 /15/21
Actual Flow Minimum Continuous Flow Requirement
Figure 4-23. Lookout Shoals Development: Figure above is excerpted from Figure 4-22 for closer
examination.
47

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.5 Cowans Ford Development
Cowans Ford Development average daily flows are summarized in Figure 4-24. There were no
deviations from the Cowans Ford Minimum Average Daily Flow requirements in 2021.
Cowans Ford 2021 Average Daily Flows
10000
1000 Sul n
3
0
ILL
100
10
1 /1 /21 3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21 1 /1 /22
Average Flow Minimum Average Daily Flow Requirement
Figure 4-24. Cowans Ford Development: Average daily flows released January 1-December 31, 2021.
Flows were calculated based on generation and spill flow data.
48

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.6 Mountain Island Development
Mountain Island Development average daily flows are summarized in Figure 4-25. There were no
deviations from the Mountain Island Minimum Average Daily Flow release requirements in 2021.
10000
1000
0
LL
100
10
1/1/21
Mountain Island 2021 Average Daily Flows
3/1 /21 5/1 /21 7/1 /21 9/1 /21 11 /1 /21 1 /1 /22
Average Flow Minimum Average Daily Flow Requirement
Figure 4-25. Mountain Island Development: Average daily flows released January 1-December 31,
2021. Flows were calculated based on generation and spill flow data.
49

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.7 Wylie Development
Wylie Development continuous flows are summarized in Figure 4-26. There were no deviations from
the Minimum Continuous Flow requirements at the Wylie Development in 2021. Minimum continuous
flow releases were increased from 1,100 cfs to 1,300 cfs from February 15 through May 15 as required
by the Wylie High Inflow Protocol.
Wylie 2021 Continuous Flows
10000
100
1/1/21 3/1/21 5/1/21 7/1/21 9/1/21 11/1/21 1/1/22
Actual Flow Minimum Continuous Flow Requirement
Figure 4-26. Wylie Development: Wylie tailrace flows recorded at USGS Gaging Station 02145910,
January 1-December 31, 2021.
50

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wylie Development recreational flows are summarized in Figure 4-27. There were no deviations from
the Wylie Recreation Flow release requirements in 2021. No official request for additional recreational
flow releases was received for the Wylie Development, but an additional 10 hours of recreational flow
releases were provided in 2021.
Wylie 2021 Recreational Flows
4800
4600
4400
4200
4000
� 3800
3600
u_
3400
3200
3000
2800
4/1 /21 5/1 /21 6/1 /21 7/1 /21 8/1 /21 9/1 /21 10/1 /21 11 /1 /21
x Actual Flow Minimum Required Flow
Figure 4-27. Wylie Development: Recreational flows recorded at USGS Gaging Station 02145910,
located 0.5 miles downstream of Wylie, April -October 2021.
51

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wylie Development flows supporting public water supply and industrial processes are summarized in
Figure 4-28. More specifically, the Wylie Development exceeded the Minimum Continuous Flow of 600
cfs as required for public water supply and industrial processes, meeting the 1,000 cfs continuous 16-
hour period each day for the New-Indy Catawba, LLC plant. There were no requests received from the
Union/Lancaster Catawba River Water Treatment Plant for the additional 71 cfs flow specified in the
License.
Wylie 2021 Flows Supporting Public Water Supply and Industrial Processes
10000
U
O
F-, 1000
100 4-
1/1/21
3/1/21 5/1/21 7/1/21 9/1/21 11/1/21 1/1/22
Actual Flow - Minimum 16-Hr Flow Requirement Minimum Continuous Flow Requirement
Figure 4-28. Wylie Development: Flows supporting public water supply and industrial processes
recorded at USGS Gaging Station 02147020, located 19 miles downstream of Wylie, January -December
2021.
52

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wylie Development weekly average flows supporting public water supply and industrial processes are
summarized in Figure 4-29. There were no deviations from weekly average flows supporting public
water supply and industrial processes recorded at USGS Gaging Station 02146000.
10000
46
U
O
F'- 1000
Wylie 2021 Weekly Average Flows
x
x xxxxxxxxx xx
xX xxxX x xx x
XX X X xX
X XxXxX X xxxx>C XXXXXXXXX>
100 4-
1/1/21
3/1/21 5/1/21 7/1/21 9/1/21 11/1/21
x Average Flow Minimum Weekly Average Flow Requirement
1/1/22
Figure 4-29. Wylie Development: Weekly average flows supporting public water supply and industrial
processes recorded at USGS Gaging Station 02146000, located 3.5 miles downstream of Wylie tailrace,
January -December 2021.
53

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.8 Fishing Creek Development
Fishing Creek Development average daily flows are summarized in Figure 4-30. There were no
deviations from the Fishing Creek Minimum Average Daily Flow requirements in 2021.
Fishing Creek 2021 Average Daily Flows
10000
5
1000
3
0
ILL
100
10
1/1/21 3/1/21 5/1/21 7/1/21 9/1/21 11/1/21 1/1/22
Average Flow Minimum Average Daily Flow Requirement
Figure 4-30. Fishing Creek Development: Average daily flows released by the Fishing Creek
Development, January 1-December 31, 2021.
4.2.9 Great Falls -Dearborn Development
In accordance with the FWQIP, the Great Falls -Dearborn Development trash gate was open and
operational from January 1 until beginning of construction on the spillway in May of 2021. Construction
is currently underway on the Long and Short Bypassed Reach flow release structures.
54

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.10 Rocky Creek -Cedar Creek Development
Rocky Creek -Cedar Creek Development average daily flows are summarized in Figure 4-31. There were
no deviations from the Rocky Creek -Cedar Creek Minimum Average Daily Flow requirements in 2021.
Rocky Creek -Cedar Creek 2021 Average Daily Flows
10000
Z
1000
3
0
ILL
100
10
1/1/21 3/1/21 5/1/21 7/1/21 9/1/21 11/1/21 1/1/22
Average Flow Minimum Average Daily Flow Requirement
Figure 4-31. Rocky Creek -Cedar Creek Development: Average daily flows released January 1-December
31, 2021, by the Rocky Creek -Cedar Creek Development.
55

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.2.11 Wateree Development
Wateree Development FWQIP Interim Flow Measures for January 1 through May 15, 2021 are
summarized in Figure 4-32. Deviations from the FWQIP Interim Flow Measures were documented on
February 4, March 9, March 10, and March 17, 2021. These deviations were associated with installation,
operation, and maintenance of the License required Trap, Sort & Transport (TST) Facility downstream of
the Wateree Development and did not require notification to the FERC. The longest consecutive non -
generation period of 6.25 hours occurred during annual TST Facility installation on February 4, 2021. All
other non -generation periods during deviations related to TST Facility operation and maintenance
occurred for an hour, or less.
10000
U
1000
100
Wateree Flow Recorded January 1 - May 15, 2021
1 /4/21 1 /18/21 2/1 /21 2/15/21 3/1 /21 3/15/21 3/29/21 4/12/21 4/26/21 5/10/21
Actual Flow 1-Unit Minimum Flow (Operational Threshold) Estimated Average 1-Unit Flow
Figure 4-32. Wateree Development: Wateree FWQIP Interim Flow Measures recorded at Wateree
Tailrace from January 1— February 14 and during required continuous 1-unit generation period
(February 15 — May 15).
56

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wateree Development FWQIP Interim Flow Measures for May 16 to August 15, 2021 are summarized in
Figure 4-33. Deviations from the FWQIP Interim Flow Measure were documented on June 1 and June 2.
The June 1 and June 2, 2021 deviations were associated with the annual TST Facility shut down and
removal and did not require communication to the FERC. Replacement flow was provided on each of
the deviation dates after the deviation occurred.
10000
10000
w
U
tL 1000
100
10000
U
3
lL 1000
100
(a) Wateree Flow Recorded May 16 - June 15, 2021
�nvtuuninnnni�mm�i�mninimm�nmu�uwi�mnuuwnnunuuwmnw�uuwi�uwn�uumumiouu��nnummu�uuniu�uuuuiun�uu�mnm�umnim�
(b) Wateree Flow Recorded June 16 - July 15, 2021
6/21 /21 7/5/21
(c) Wateree Flow Recorded July 16 - August 15, 2021
7/19/21 8/2/21
Actual Flow 1-Unit Minimum Flow (Operational Threshold) Estimated Average 1-Unit Flow
Figure 4-33. Wateree Development: Wateree FWQIP Interim Flow Measure flows recorded at Wateree
Tailrace from (a) May 16 — June 15, (b) June 16 — July 15, and (c) July 16 — August 15.
57

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wateree Development FWQIP Interim Flow Measures from August 16 to November 15, 2021 are
summarized in Figure 4-34. Deviations from the FWQIP Interim Flow Measure were documented on
August 31 and October 7. The August 31 deviation was associated with a raw water line repair (see
Table 4-2). The October 7 deviation was associated with TST Facility maintenance (i.e. shoreline
stabilization) and did not require FERC notification. Replacement flow was provided on each of the
deviation dates after the deviation occurred.
10000
100
8/1
10000
100
10000
100
(a) Wateree Flow Recorded August 16 - September 15, 2021
10/18/21 11 /1 /21 11 /15/21
Actual Flow 1-Unit Minimum Flow (Operational Threshold) Estimated Average 1-Unit Flow
58

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Figure 4-34. Wateree Development: Wateree FWQIP Interim Flow Measure deviations recorded at
Wateree Tailrace from (a) August 16 — September 15, (b) September 16 - October 15, (c) October 16 —
November 15.
Wateree Development FWQIP Interim Flow Measures from November 16 to December 15, 2021 are
summarized in Figure 4-35. There were no deviations from the FWQIP Interim Flow Measure
requirements in 2021.
Wateree Flow Recorded November 16 - December 31, 2021
10000
111
Figure 4-35. Wateree Development: Wateree FWQIP Interim Flow Measure deviations recorded at
Wateree Tailrace from November 16 — December 31, 2021.
59

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wateree Development recreational flow releases from April 1 to October 1 are summarized in Figure 4-
36 and Figure 4-37. There were no deviations from the Wateree recreation flow release requirements in
2021. No official request for additional recreational flow releases was received for the Wateree
Development, but an additional 10 hours of recreational flow releases were provided in 2021.
3200
3100
3000
0 2900
ILL
2800
2700
4/ 1 /21
Wateree 2021 Recreational Flows at Tailrace
�Ipi11x•"
5/1 /21 6/1 /21 7/1 /21 8/1 /21 9/1 /21 10/1 /21 11 /1 /21
x Actual Flow Minimum Required Flow
Figure 4-36. Wateree Development: Recreational flows released by the Wateree Development from
10:00-15:00 on recreational flow release dates, April -October 2021.
.E

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Instantaneous flows measured at USGS Gaging Station 02148000 from 13:00 to 18:00 are plotted in
Figure 4-37 alongside average flows for the same period. Flows presented allow three hours for flows
released at the Wateree Development from 10:00 to 15:00 to be fully manifested 7.4 miles downstream
at the USGS Gaging Station 02148000. Average flows measured at the gaging station from 13:00 to
18:00 approximated or exceeded the compliance minimum recreational flow of 2,760 cfs on all but five
dates: October 10, October 23, and October 24, October 30, and October 31. On these dates, average
flows were within 10 % of the required minimum recreational flow. Individual instantaneous flows
dropped below the minimum required flow on these, and other dates; however, Figure 4-36 indicated
the recreational minimum flow was met as measured by generation records from Wateree Hydro
Station.
8000
7000
6000
5000
6 4000
LL
3000
2000
1000
Wateree 2021 Recreational Flows at Camden
x X
x X
x
X x x
X XX XX X XX XX XXXX XX X
X X X XX XX X
4/1 /21 5/1 /21 6/1 /21 7/1 /21 8/1 /21 9/1 /21 10/1 /21 11 /1 /21
x Actual Flow Minimum Flow Requirement • Average Recreational Flow
Figure 4-37. Wateree Development: Flows measured at USGS Gaging Station 02148000 from 13:00-
18:00, allowing three hours for recreational flows released 10:00-15:00 at the Wateree Development
to be fully manifested 7.4 miles downstream at USGS Gaging Station 02148000.
61

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wateree Development flows supporting public water supply and industrial processes are summarized in
Figure 4-38. Instantaneous flows dropped below the required minimum flows for supporting public
water supply and industrial processes at USGS Gaging Station 02148000 on June 2, August 31, and
October 7. USGS Gaging Station 0214800 is the closest active gaging station and is located 7.4 miles
downstream of the Wateree Hydro Station. This is more than 50 miles upstream of River Mile 12 for the
South Carolina Electric & Gas Company's [now Dominion Energy South Carolina] Wateree Steam Station
and for the International Paper facility at River Mile 17.
Historically, a USGS gaging station (02148351) at Eastover, South Carolina recorded flows in the Wateree
River at River Mile 12 specified in the License. This gaging station was retired in 2014. Flows at River
Mile 12 near the retired USGS Gaging Station 02148351 were estimated for this report using USGS
Gaging Station 0214800 flow data and drainage area ratio calculations outlined in Gianfagna et al, 2015.
There is a 10 % incremental increase in flow from the USGS Gaging Station at Camden, SC (0214800) to
the USGS Gaging Station 02148351 at Eastover, SC based on their drainage ratios. The minimum
estimated instantaneous flow for River Mile 12 in 2021 was 806 cfs. The minimum estimated daily
average flow was 1,389 cfs. Estimated minimum flow at River Mile 12 demonstrates Wateree River
flows exceeded the minimum required flows for supporting public water supply and industrial
processes.
Wateree 2021 Flows Supporting Public Water Supply and Industrial Processes
10000
U)
U 1000
IL
100
10
1 /1 /21 3/1 /21 5/1 /21 7/1 /21 9/ 1 /21 11 /1 /21 1 /1 /22
Actual Flow Minimum Required Flow
Figure 4-38. Wateree Development: Wateree Flows supporting public water supply and industrial
processes recorded at USGS Gaging Station 02148000, January 1-December 31, 2021.
62

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3 Water Quality Article Compliance
This report serves as notification to the FERC of deviations from Water Quality Articles for 2021. Table
4-3 summarizes 2021 Water Quality Article deviations for all developments. Compliance with
instantaneous and daily average DO state standards were each achieved at 99.9 % for the Project.
Compliance with instantaneous state temperature standards was achieved at 100 % for the Project.
Table 4-3. Summary of All Water Quality Article Deviations in 2021.
Instantaneous DO
Daily Average DO
Deviations from State
Deviations from State
Instantaneous Temperature
Development
Standard
Standard
Deviations from State Standard
Bridgewater
No Deviations
No Deviations
No Deviations
Rhodhiss
No Deviations
No Deviations
No Deviations
Oxford
No Deviations
No Deviations
No Deviations
Lookout Shoals
No Deviations
No Deviations
No Deviations
Cowans Ford
5 (see text)
1 (see text)
No Deviations
Mountain Island
No Deviations
No Deviations
No Deviations
Wylie
No Deviations
No Deviations
No Deviations
Fishing Creek
6 (see text)
No Deviations
No Deviations
Great Falls/Dearborn
No Deviations
No Deviations
No Deviations
Rocky Creek/Cedar Creek
No Deviations
No Deviations
No Deviations
Wateree
Not Required
Not Required
Not Required
63

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Water quality data collected for Water Quality Article compliance are presented graphically via boxplots
by development. These plots are a tool to visualize distribution of large data sets. Plots include the
applicable state water quality standard, including instantaneous DO, daily average DO, and
instantaneous temperature, for comparison. Figure 4-39 is an example boxplot highlighting the
components of the boxplots presented in the following sections. Specific numeric water quality
standards applicable to each development are provided in the development -specific Article
Requirement section of this report.
Water Quality Article Compliance Example DO Format
14
12
WQ Standard
4
2
e �- Maximum Value
.� 95th Percentile
{f 75th Percentile
50th Percentile (median)
'~ 25th Percentile
5th Percentile
*--- Minimum Value
May
Figure 4-39. Example boxplot for representing water quality datasets in this report.
64

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.1 Bridgewater Development (Lake James)
Bridgewater Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-40. The Bridgewater Development met all North Carolina water quality
standards for instantaneous DO in 2021.
14
12
J
E 10
C
N
0)
0 $
0 6
U)
cn
r1w
4
2
Bridgewater Instantaneous Tailrace DO Summary by Month
13
13
E? 13
E23
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-40. Bridgewater Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Bridgewater Tailrace at USGS Water Quality Monitoring Station
02138520, April 1-November 30, 2021.
65

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Bridgewater Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-41. The Bridgewater Development met all North Carolina water quality
standards for daily average DO in 2021.
J
E
O
O)
X
N
O
�dw
12
10
0
0
4
2
Bridgewater Daily Average Tailrace DO Summary By Month
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-41. Bridgewater Development: Summary of daily average dissolved oxygen (DO)
concentrations recorded in the Bridgewater Tailrace at USGS Water Quality Monitoring Station
02138520, April 1-November 30, 2021.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Bridgewater Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-42. The Bridgewater Development met all North Carolina water quality
standards for instantaneous temperature in 2021.
Bridgewater Instantaneous Tailrace Temperature Summary by Month
35
ME
�) 25
O
20
i
N
Q
!_
H 15
10
5
o �
o ■
0
■
0 0 ■
n ■ ■
Su— ■
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-42. Bridgewater Development: Summary of instantaneous water temperature recorded in
the Bridgewater Tailrace at USGS Water Quality Monitoring Station 02138520, April 1-November 30,
2021.
67

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.2 Rhodhiss Development
Rhodhiss Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-43. The Rhodhiss Development met all North Carolina water quality standards
for instantaneous DO in 2021.
14
12
J
E 10
C
0 8
4)
0 6
U)
U)
r1
4
2
Rhodhiss Instantaneous Tailrace DO Summary by Month
■
n o
0
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-43. Rhodhiss Development: Summary of instantaneous dissolved oxygen (DO) concentrations
recorded in the Rhodhiss Tailrace at USGS Water Quality Monitoring Station 02141500 while Rhodhiss
Hydro Station was generating, April 1-November 30, 2021.
m

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Rhodhiss Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-44. The Rhodhiss Development met all North Carolina water quality standards
for daily average DO in 2021.
rid
12
10
IA
(on
4
2
Rhodhiss Daily Average Tailrace DO Summary By Month
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-44. Rhodhiss Development: Summary of daily averages of dissolved oxygen (DO)
concentrations recorded in the Rhodhiss Tailrace while Rhodhiss Hydro Station was generating, April
1-November 30, 2021.
.•

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Rhodhiss Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-45. The Rhodhiss Development met all North Carolina water quality standards
for instantaneous temperature in 2021.
Rhodhiss Instantaneous Tailrace Temperature Summary by Month
35
& 25
0
20
Q
H 15
10
5
o 13
0
o
■
0
0
■
0
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-45. Rhodhiss Development: Summary of instantaneous temperatures recorded in the
Rhodhiss Tailrace at USGS Water Quality Monitoring Station 02141500 while Rhodhiss Hydro Station
was generating, April 1-November 30, 2021.
70

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.3 Oxford Development (Lake Hickory)
Oxford Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-46. The Oxford Development met all North Carolina water quality standards for
instantaneous DO in 2021.
lid
14
12
4
2
Oxford Instantaneous Tailrace DO Summary by Month
n
13
L� [D 13 13
13
0
�J
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-46. Oxford Development: Summary of instantaneous dissolved oxygen (DO) concentrations
recorded in the Oxford Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-
November 30, 2021.
71

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Oxford Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-47. The Oxford Development met all North Carolina water quality standards for
daily average DO in 2021.
12
10
J
C
N 8
X
0
6
0
U)
0
4
2
Oxford Daily Average Tailrace DO Summary By Month
11
EID
EID
13
ED
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-47.Oxford Development: Summary of daily average dissolved oxygen (DO) concentrations
recorded in the Oxford Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-
November 30, 2021.
72

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Oxford Development instantaneous temperatures from April through November 2021 are summarized
in Figure 4-48. The Oxford Development met all North Carolina water quality standards for
instantaneous temperature in 2021.
Oxford Instantaneous Tailrace Temperature Summary by Month
35
GIB
�j 25
0
m
20
N
Q
E
15
10
5
° °
° ■
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-48. Oxford Development: Summary of instantaneous temperatures recorded in the Oxford
Tailrace at USGS Water Quality Monitoring Station 0214196125, April 1-November 30, 2021.
73

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.4 Lookout Shoals Development
Lookout Shoals Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-49. The Lookout Shoals Development met all North Carolina water quality
standards for instantaneous DO in 2021.
5
Lookout Shoals Instantaneous Tailrace DO Summary by Month
12
0
0
10
A
4
2
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-49. Lookout Shoals Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station
0214244102, April 1-November 30, 2021.
74

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Lookout Shoals Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-50. The Lookout Shoals Development met all North Carolina water quality
standards for daily average DO in 2021.
J
0)
!_
C
a)
0)
X
0
N
O
W
12
10
0
0
4
2
Lookout Daily Average Tailrace DO Summary By Month
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-50. Lookout Shoals Development: Summary of daily average dissolved oxygen (DO)
concentrations recorded in the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station
0214244102, April 1-November 30, 2021.
75

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Lookout Shoals Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-51. The Lookout Shoals Development met all North Carolina water quality
standards for instantaneous temperature in 2021.
Lookout Shoals Instantaneous Tailrace Temperature Summary by Month
35
30
E
15
10
5
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-51. Lookout Shoals Development: Summary of instantaneous tailrace temperatures recorded
in the Lookout Shoals Tailrace at USGS Water Quality Monitoring Station 0214244102, April 1-
November 30, 2021.
76

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.5 Cowans Ford Development (Lake Norman)
Cowans Ford Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-52. In 2021, there were five recorded instantaneous DO measurements below
the 4.0 mg/L North Carolina standard for instantaneous DO. One reading occurred on August 30 and the
other four readings occurred on September 1 (Figure 4-53). The recorded values were coincident with a
brief mixing event that occurred on Lake Norman presumably due to meteorological and biological
conditions. Lake Norman DO profiles on September 1 confirmed lower DO values (< 4.0 mg/L) at
elevations near the withdrawal zone for the Cowans Ford intake that would account for the lower DO
values. Subsequent Lake Norman DO profiles on September 2 confirmed the DO values in the lake near
the intake withdrawal zone quickly returned to DO concentrations above 4.0 mg/L. Lake Norman DO
profile data for September 1 and 2 are provided in Appendix (C-1).
14
12
J
E 10
C
N
0 $
0 6
U)
4
2
Cowans Ford Instantaneous Tailrace DO Summary by Month
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-52. Cowans Ford Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Cowans Ford Tailrace at USGS Water Quality Monitoring Station
0214264790 when Cowans Ford Hydro Station was generating, April 1-November 30, 2021.
77

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
12
J 10
0)
E
8
x
O
6
0
0 4
2 4—
08/01 /21
Cowans Ford Aug and Sep Instantaneous DO Data
09/01 /21
Instantaneous DO State Instantaneous DO Standard
Figure 4-53. Cowans Ford Development: Tailrace instantaneous dissolved oxygen (DO) concentrations
from August 1-September 30, 2021, documenting deviations from the North Carolina instantaneous
DO standard of >_ 4.0 mg/L while Cowans Ford Hydro Station was generating.
78

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Cowans Ford Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-54. In 2021, there was one daily average DO concentration below the 5.0 mg/L
North Carolina daily average DO standard (see Figure 4-55). The low DO value was associated with the
brief mixing event on Lake Norman described above.
Cowans Ford Daily Average Tailrace DO Summary By Month
12
10
J
0)
C
N 8
X
0
6
0
Cn
4
2
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-54. Cowans Ford Development: Summary of daily averages of DO concentrations recorded at
USGS Water Quality Monitoring Station 0214264790 in the Cowans Ford Tailrace while Cowans Ford
Hydro Station was generating, April 1-November 30, 2021.
79

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
J
0)
C
N
X
0
O
O
cn
U)
r1w
12
10
0
(on
4
2+
Aug
Cowans Ford Aug and Sep Daily Average Tailrace DO
Sep
• Daily Average DO State Daily Average DO Standard
Oct
Figure 4-55. Cowans Ford Development: Daily averages of DO concentrations recorded at USGS Water
Quality Monitoring Station 0214264790 in the Cowans Ford Tailrace while Cowans Ford Hydro Station
was generating, August 1-October 1, 2021, documenting deviations from the North Carolina standard
for daily average DO >_ 5.0 mg/L.
:N

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Cowans Ford Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-56. The Cowans Ford Development met all North Carolina water quality
standards for instantaneous temperature in 2021.
Cowans Ford Instantaneous Tailrace Temperature Summary by Month
35
30
& 25
0
L
20
Q
E
15
10
5
0
o o
■
0
0
■
o ■
0
■
0
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-56. Cowans Ford Development: Summary of instantaneous temperatures recorded in the
Cowans Ford Tailrace at USGS Water Quality Monitoring Station 0214264790 while Cowans Ford
Hydro Station was generating, April 1-November 30, 2021.
81

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.6 Mountain Island Development
Mountain Island Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-57. The Mountain Island Development met all North Carolina water quality
standards for instantaneous DO in 2021.
Mountain Island Instantaneous Tailrace DO Summary by Month
14
12
J
E 10
C
N
0)
0 $
0 6
rn
w
4
2
0
o
0
0
■ � o n
■
o n
■ E�p ■
■
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-57. Mountain Island Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Mountain Island tailrace at USGS Water Quality Monitoring Station
0214267602 while Mountain Island Hydro Station was generating, April 1-November 30, 2021.
82

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Mountain Island Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-58. The Mountain Island Development met all North Carolina water quality
standards for daily average DO in 2021.
J
E
C
X
N
O
W
Mountain Island Daily Average Tailrace DO Summary By Month
12
10
0
0
4
2
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-58. Mountain Island Development: Summary of daily averages of dissolved oxygen (DO)
concentrations recorded at USGS Water Quality Monitoring Station 0214267602 in the Mountain
Island Tailrace while Mountain Island Hydro Station was generating, April 1-November 30, 2021.
83

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Mountain Island Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-59. The Mountain Island Development met all North Carolina water quality
standards for instantaneous temperature in 2021.
Mountain Island Instantaneous Tailrace Temperature Summary by Month
35
30
j 25
0
CU 20
^L,
W
Q
E
H 15
10
5
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-59. Mountain Island Development: Summary of instantaneous temperatures recorded in the
Mountain Island tailrace at USGS Water Quality Monitoring Station 0214267602 while Mountain
Island Hydro Station was generating, April 1-November 30, 2021.
84

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.7 Wylie Development
Wylie Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-60. The Wylie Development met all South Carolina water quality standards for
instantaneous DO in 2021.
J
0)
!_
C
O
0)
X
0
N
O
U)
U)
r1w
12
10
0
0
4
2
Wylie Instantaneous Tailrace DO Summary by Month
13
13
E Ell
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-60. Wylie Development: Summary of instantaneous tailrace dissolved oxygen (DO)
concentrations recorded in the Wylie Tailrace at USGS Water Quality Monitoring Station 02145910,
April 1-November 30, 2021.
8S

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wylie Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-61. The Wylie Development met all South Carolina water quality standards for
daily average DO in 2021.
J
!_
C
a)
0)
X
0
N
O
U)
W
12
10
0
0
4
2
Wylie Daily Average Tailrace DO Summary By Month
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-61. Wylie Development: Summary of daily average dissolved oxygen (DO) concentrations
recorded in the Wylie Tailrace at USGS Water Quality Monitoring Station 02145910, April 1-November
30, 2021.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wylie Development instantaneous temperatures from April through November 2021 are summarized in
Figure 4-62. The Wylie Development met all North Carolina water quality standards for instantaneous
temperature in 2021.
Wylie Instantaneous Tailrace Temperature Summary by Month
35
GIB
�j 25
0
20
L
Q
15
10
5
o n
o
■
0
■
0
0
■ Ej�3
n ■ o
■
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-62. Wylie Development: Summary of instantaneous tailrace temperatures recorded in the
Wylie tailrace at USGS Water Quality Monitoring Station 02145910, April 1-November 30, 2021.
87

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.8 Fishing Creek Development
Fishing Creek Development instantaneous DO concentrations from April through November 2021 are
summarized in Figure 4-63. In 2021 there were six recorded instantaneous DO values that were below
the 4.0 mg/L North Carolina standard for instantaneous DO (Figure 4-64). Two recorded values occurred
on July 19, two on July 25, and two on July 26. The minimum recorded value was 3.5 mg/L occurring on
July 26. As in previous years, all recorded values occurred near the startup of unit generation and
subsequent recorded values were above 4.0 mg/L. These brief deviations did not result in a daily
average DO below the 5.0 mg/L North Carolina standard (see Figure 4-65).
14
12
J
E 10
C
W
O $
N
0 6
rw
4
2
Fishing Creek Instantaneous Tailrace DO Summary by Month
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-63. Fishing Creek Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Fishing Creek tailrace at USGS Water Quality Monitoring Station
02147310 while Fishing Creek Hydro Station was generating, April 1-November 30, 2021.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
10
9
0)
E
c 8
m
0)
O 7
6
0
5
0
4
3 4-
07/01 /21
Fishing Creek July Instantaneous DO Data
7/6/21 7/13/21 7/20/21 7/27/21
Instantaneous DO State Instantaneous DO Standard
08/01 /21
Figure 4-64. Fishing Creek Development: Instantaneous dissolved oxygen (DO) concentrations
recorded in the Fishing Creek Tailrace at USGS Water Quality Monitoring Station 02147310 while
Fishing Creek Hydro Station was generating, July 1-August 1, 2021, demonstrating deviations from the
South Carolina >_ 4.0 mg/L instantaneous DO standard.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Fishing Creek Development daily average DO concentrations from April through November 2021 are
summarized in Figure 4-65. The Fishing Creek Development met all South Carolina water quality
standards for daily average DO in 2021.
Fishing Creek Daily Average Tailrace DO Summary By Month
12
10
J
CM
C 8
N
6
0
we
4
2
13
13
E? 13 E
Apr May Jun Jul Aug Sep Oct Nov
State Daily A\terage DO Standard
Figure 4-65. Fishing Creek Development: Summary of daily averages of dissolved oxygen (DO)
concentrations recorded in the Fishing Creek Tailrace at USGS Water Quality Monitoring Station
02147310 while Fishing Creek Hydro Station was generating, April 1-November 30, 2021.
a

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Fishing Creek Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-66. The Fishing Creek Development met all South Carolina water quality
standards for instantaneous temperature in 2021.
Fishing Creek Instantaneous Tailrace Temperature Summary by Month
35
30
�j 25
0
15
10
5
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-66. Fishing Creek Development: Summary of instantaneous temperatures recorded in the
Fishing Creek Tailrace at USGS Water Quality Monitoring Station 02147310 while Fishing Creek Hydro
Station was generating, April 1-November 30, 2021.
91

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.9 Great Falls -Dearborn Development
Great Falls -Dearborn Development instantaneous DO concentrations from April through November
2021 are summarized in Figure 4-67. The Great Falls -Dearborn Development met all South Carolina
water quality standards for instantaneous DO in 2021. The minimum value recorded in June was 4.0
mg/L.
Great Falls -Dearborn InstantaneousTaiIrace DO Summary by Month
14
12
J
E 10
C
4)
0 8
W
0 6
�Id
4
2
°
° E?
°
■
E;;� E]�
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-67. Great Falls -Dearborn Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Great Falls -Dearborn Tailrace at USGS Water Quality Monitoring
Station 021474095 while Dearborn Hydro Station was generating, April 1-November 30, 2021.
92

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Great Falls -Dearborn Development daily average DO concentrations from April through November 2021
are summarized in Figure 4-68. The Great Falls -Dearborn Development met all South Carolina water
quality standards for daily average DO in 2021.
Great Falls -Dearborn Daily Average Tailrace DO Summary By Month
12
10
•
4
2
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-68. Great Falls -Dearborn Development: Summary of daily averages of tailrace dissolved
oxygen (DO) concentrations recorded in the Great Falls -Dearborn tailrace at USGS Water Quality
Monitoring Station 021474095 while Dearborn Hydro Station was generating, April 1-November 30,
2021.
93

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Great Falls -Dearborn Development instantaneous temperatures from April through November 2021 are
summarized in Figure 4-69. The Great Falls -Dearborn Development met all South Carolina water quality
standards for instantaneous temperature in 2021.
Great Falls -Dearborn Instantaneous Tailrace Temperature Summary by Month
35
30
& 25
O
L
20
Q
E
H 15
10
A
o
o
o
0
■
0
■
0
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-69. Great Falls -Dearborn Development: Summary of instantaneous temperatures recorded in
the Great Falls -Dearborn Tailrace at USGS Water Quality Monitoring Station 021474095 while
Dearborn Hydro Station was generating, April 1-November 30, 2021.
94

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.10 Rocky Creek -Cedar Creek Development
Rocky Creek -Cedar Creek Development instantaneous DO concentrations from April through November
2021 are summarized in Figure 4-70. The Rocky Creek -Cedar Creek Development met all South Carolina
water quality standards for instantaneous DO in 2021.
Rocky Creek -Cedar Creek Instantaneous Tailrace DO Summary by Month
14
12
J
0)
E 10
C
O $
N
0 6
U)
U)
MI
4
2
13
13
e$13
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous DO Standard
Figure 4-70. Rocky Creek -Cedar Creek Development: Summary of instantaneous dissolved oxygen (DO)
concentrations recorded in the Cedar Creek Tailrace at USGS Water Quality Monitoring Station
02147505 while Cedar Creek Hydro Station was generating, April 1-November 30, 2021.
9S

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Rocky Creek -Cedar Creek Development daily average DO concentrations from April through November
2021 are summarized in Figure 4-71. The Rocky Creek -Cedar Creek Development met all South Carolina
water quality standards for daily average DO in 2021.
Rocky Creek -Cedar Creek Daily Average Tailrace DO Summary By Month
J
0)
E
C
N
X
0
O
O
W
12
10
M
A
4
2
13
13
13
F Fil
Apr May Jun Jul Aug Sep Oct Nov
State Daily Average DO Standard
Figure 4-71. Rocky Creek -Cedar Creek Development: Summary of daily averages of dissolved oxygen
(DO) concentrations recorded in the Cedar Creek Tailrace at USGS Water Quality Monitoring Station
02147505 while Cedar Creek Hydro Station was generating, April 1-November 30, 2021.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Rocky Creek -Cedar Creek Development instantaneous temperatures from April through November 2021
are summarized in Figure 4-72. The Rocky Creek -Cedar Creek Development met all South Carolina water
quality standards for instantaneous temperature in 2021.
Rocky Creek -Cedar Creek Instantaneous Tailrace Temperature Summary by Month
35
30
& 25
20
N
Q
E
15
10
0
o n
o
o
0
■
n
■ n
Apr May Jun Jul Aug Sep Oct Nov
State Instantaneous Temperature Standard
Figure 4-72. Rocky Creek -Cedar Creek Development: Summary of instantaneous temperatures
recorded in the Cedar Creek Tailrace at USGS Water Quality Monitoring Station 02147505 while Cedar
Creek Hydro Station was generating, April 1-November 30, 2021.
97

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
4.3.11 Wateree Development
The Wateree Development was subject to compliance with FWQIP interim measures for DO
enhancement as described in Section 3.3. On July 16 at 18:30, July 24 at 22:45, July 28 at 05:00, July 30
at 08:00, and August 3 at 08:00, 11:00, and 14:00, instantaneous DO values recorded in the tailrace
dropped below 4 mg/L. During these periods Unit 1 or Unit 3 were required to be operated first on and
last off to provide aeration in the tailrace. On these dates and times, generation at the Wateree
Development followed the FWQIP interim measures as shown in Figures 4-73 through 4-77.
a
8
3
Wateree Development Interim Measures on July 16
Unit 1 generating according to Interim
Measures far Providing D❑ Enhancement
x
x
x 000c x+000c
x xx xx "IX
x z x x
x x
WX x X
x
XXX
20000
15000
w
10000 3
b
5000
07/16/21 00:00:00 07/16/21 12:00:00 07/17/21 00:00:00
x Instantaneous DO State Instantaneous DO Standard -- Interim Measure Generation Flow
Figure 4-73. Wateree Development: Water quality and flow in the Wateree tailrace on July 16
demonstrating compliance with Interim Measures for Providing DO Enhancement.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
=111
8
Wateree Development Interim Measures on July 24
Unit 1 generating according to Interim
Measures for Providing DO Enhancement
xaa % X*Wx
>WX xx x
xx x x50Keep(,
x rac ^'X'
x x
roc
x x x x xx
x
E
31
7124121 00:00:00
x Instantaneous DO
20000
15000
10000 9
v
LL
5000
7124121 12:D0:00 7125121 D0:00:00
State Instantaneous DO Standard Interim Measure Generation Flow
Figure 4-74. Wateree Development: Water quality and flow in the Wateree tailrace on July 24
demonstrating compliance with Interim Measures for Providing DO Enhancement.

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Wateree Development Interim Measures on July 28
9
8
J
E 7
xaocc
x
ofi
x x
3 x x
a $
Y) x
x
❑ x
4 XX
3
,*..— Unit 1 generating according to Interim
Measures for Providing DO Enhancement
j20°5c BSc J0G�5ooe'0G'" XVQ
x x Xx
x
yx BSc
x
x
x
XI -IX x
20000
15000
10000
v
CL
FjD�■
07/28/21 00:00:00 07128/21 12:00:00 07129t21 00:00:00
x Instantaneous DO — State Instantaneous DO Standard Interim Measure Generation Flow
Figure 4-75. Wateree Development: Water quality and flow in the Wateree tailrace on July 28
demonstrating compliance with Interim Measures for Providing DO Enhancement.
100

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
a
8
J
w
7
c
N
x 6
D
3 $
a
4
3
Wateree Development Interim Measures on July 30
Unit 1 generating according to Interim
Measures for Providing DO Enhancement
xc �
�x� x
x
x
i x
Ll
20000
15000
ry..
10000
FL
5000
07/30/21 00:00:00 07/30/21 12:00:00 07/31 /21 00:00:00
x Instantaneous DO — State Instantaneous DO Standard Interim Measure Generation Flow
Figure 4-76. Wateree Development: Water quality and flow in the Wateree tailrace on July 30
demonstrating compliance with Interim Measures for Providing DO Enhancement.
101

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
J
9
8
3
Wateree Development Interim Measures on August 3
Unit 1 generating according to Interim
Measures for Providing DO Enhancement
74a
x
x>2°'
x
x x x
10C
x Axx tat?
xx x � x
x
- 20000
15000
x
Xx
10000
xX
LL
�
50M
n
08/03/21 00:00:00 08/03/21 12:00:00 08104/21 00:00:00
x Instantaneous DO — State Instantaneous DO Standard — Interim Measure Generation Flow
Figure 4-77. Wateree Development: Water quality and flow in the Wateree tailrace on August 3
demonstrating compliance with Interim Measures for Providing DO Enhancement.
102

2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
5 References
Duke Energy Carolinas, LLC. 2017. Application for Amendment of License and Submittal of Flow and
Water Quality Implementation Plan and Water Quality Monitoring Plan Catawba-Wateree
Project No. 2232. May 5, 2017.
Federal Energy Regulatory Commission (FERC). 2015. Order Issuing New License for Project Number
2232-522; Duke Energy Carolinas Catawba-Wateree. November 25, 2015. FERC Order 153
62,134.
Gianfagna, C. C., Johnson, C., Chandler, D., Hoffman, C. (2015). Watershed area ratio accurately
predicts daily streamflow in nested catchments in the Catskills, New York. Journal of Hydrology:
Regional Studies, 4 (Part B), 583 — 594.
North Carolina Department of Environmental Quality. November 1, 2019. Division of Water Quality.
Accessed June 7,2022. <https:Hfiles.nc.gov/ncdeq/documents/files/15A_NCAC_02B_.0100-
.0300_0.pdf>.
South Carolina Department of Health and Environmental Control. June 26, 2020. Regulation 61-68
Water Classifications and Standards. Accessed June 7,2022.
<https://scdhec.gov/sites/default/files/Library/Regulations/R.61-68.pdf>.
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2021 Catawba-Wateree Hydroelectric Project Compliance Report
Reservoir Elevation, Flow, and Water Quality
Appendices
Appendix A-1: Excel Spreadsheet - 2021 Hourly Reservoir Elevation Data
Appendix B-1: Excel Spreadsheet - 2021 Raw Data Set for USGS Gages and
Generation Records
Appendix C-1: Excel Spreadsheet - Flow Release Data Summary
Appendix D-1: Excel Spreadsheet - Water Quality Data Summary
104