PEE DEE RIVER INSTREAM FLOW STUDY FINAL REPORT...Yadkin-Pee Dee River Hydroelectric Project FERC No....

Yadkin-Pee Dee River Hydroelectric Project FERC No. 2206

PEE DEE RIVER INSTREAM FLOW STUDY

FINAL REPORT

Water Resources Working Group Issue No. 5 - Evaluate the Relationships Between Project

Operations/Hydraulics and Aquatic Habitat, Water Quality, and Fish Migrations

PROGRESS ENERGY

APRIL 2006

© 2006 Progress Energy

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TABLE OF CONTENTS

Section Title Page No. ACRONYM LIST ....................................................................................................AL-1 SECTION 1 - PEE DEE RIVER INSTREAM FLOW STUDY REPORT ............................... 1-1 1.1 Introduction ................................................................................................................... 1-1

1.1.1 Study Purpose and Basis ................................................................................. 1-1 1.1.2 Resource Management Goals for the Pee Dee River Pertinent to the Instream Flow Study ....................................................................................... 1-2 1.1.3 Pee Dee River Instream Flow Study Objectives............................................. 1-4 1.1.4 Previous License Conditions on Instream Flow ............................................. 1-7 1.1.5 Consultation .................................................................................................... 1-7 1.1.6 Report Organization and Purpose ................................................................... 1-8

SECTION 2 - GENERAL CONCEPTS OF PHABSIM.................................................... 2-1 SECTION 3 - PROJECT LOCATION, DESCRIPTION, AND OPERATION .......................... 3-1 3.1 Tillery Development...................................................................................................... 3-1

3.1.1 Location .......................................................................................................... 3-1 3.1.2 Description ...................................................................................................... 3-1 3.1.3 Operations ....................................................................................................... 3-3

3.2 Blewett Falls Development ........................................................................................... 3-3 3.2.1 Location .......................................................................................................... 3-3 3.2.2 Description ...................................................................................................... 3-3 3.2.3 Operations ....................................................................................................... 3-4

SECTION 4 - PROJECT AREA DESCRIPTION............................................................... 4-1 4.1 The Yadkin-Pee Dee River Basin.................................................................................. 4-1 4.2 Climate .......................................................................................................................... 4-1 4.3 Physiography ................................................................................................................. 4-1 4.4 Hydrography.................................................................................................................. 4-1 4.5 Land Use........................................................................................................................ 4-2 4.6 Water Uses..................................................................................................................... 4-2

TABLE OF CONTENTS (Continued)

Section Title Page No.

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SECTION 5 - AFFECTED SPECIES, PERIODICITY, AND HABITAT SUITABILITY CRITERIA................................................................................................................. 5-1 5.1 Selection of Target Species and Habitat Guilds ............................................................ 5-1 5.2 Habitat Suitability Criteria ............................................................................................ 5-4 5.3 Species and Life Stage Periodicity ................................................................................ 5-4 SECTION 6 - PHABSIM STUDY DESIGN.................................................................. 6-1 6.1 Introduction ................................................................................................................... 6-1

6.1.1 Study Area and Study Reach .......................................................................... 6-1 6.1.2 Study Subreaches ............................................................................................ 6-2 6.1.3 Study Transects ............................................................................................... 6-3

SECTION 7 - FIELD DATA COLLECTION ................................................................... 7-1 7.1 Introduction ................................................................................................................... 7-1 7.2 Surveying and Controls ................................................................................................. 7-1 7.3 Channel Structure .......................................................................................................... 7-1 7.4 Hydraulics...................................................................................................................... 7-1 7.5 Substrate and Cover....................................................................................................... 7-3 7.6 Habitat Mapping............................................................................................................ 7-4 SECTION 8 - HABITAT AND NAVIGATION MODELS .................................................. 8-1 8.1 PHABSIM Model .......................................................................................................... 8-1

8.1.1 Introduction..................................................................................................... 8-1 8.1.2 PHABSIM Programs....................................................................................... 8-1 8.1.3 Hydraulic Model Procedures .......................................................................... 8-1 8.1.4 Model Review and Approval .......................................................................... 8-2 8.1.5 Hydraulic Model Performance........................................................................ 8-3 8.1.6 Habitat Model Procedures............................................................................... 8-4 8.1.7 Transect Weighting ......................................................................................... 8-5

8.2 Habitat Duration Model................................................................................................. 8-7 8.2.1 Description of Habitat Duration Model .......................................................... 8-7 8.2.2 Habitat Duration Analysis Program Used....................................................... 8-7 8.2.3 Hydrologic Data Sources ................................................................................ 8-8 8.2.4 Hydrologic Nodes ........................................................................................... 8-9 8.2.5 Model Runs ................................................................................................... 8-10 8.2.6 HDA Interactive Analytical Tool.................................................................. 8-10



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8.3 Peaking Flow Analysis ................................................................................................ 8-11 8.4 Wetted Perimeter and Mussel Transects ..................................................................... 8-13 8.5 Navigation Model........................................................................................................ 8-14

8.5.1 Description of Navigation Model ................................................................. 8-14 8.5.2 Model Procedures ......................................................................................... 8-15

SECTION 9 - RESULTS AND ANALYSIS ..................................................................... 9-1 9.1 Weighted Useable Area................................................................................................. 9-1 9.2 Habitat Duration Analysis ............................................................................................. 9-4

9.2.1 Habitat Duration Results ................................................................................. 9-4 9.2.2 Habitat Duration Analysis............................................................................... 9-6

9.3 Dual Flow Results ......................................................................................................... 9-7 9.4 Wetted Perimeter and Mussel Transect Results .......................................................... 9-11 9.5 Navigation and Fish Passage Results .......................................................................... 9-12 SECTION 10 - LITERATURE CITED.......................................................................... 10-1 APPENDICES (In digital compressed .zip format linked from the following list) APPENDIX A - STUDY PLAN AND CONSULTATION

A-1 - RWG ISSUES TEMPLATE A-2 - PEE DEE IFIM STUDY PLAN A-3 - SUMMARIES OF CONSULTATION

APPENDIX B - HABITAT SUITABILITY CRITERIA B-1 - PEE DEE HSC MASTER LIST B-2 - ASSUMPTIONS B-3 - CITATION MATERIAL B-4 - GUILD KEY B-5 - HSI DOCUMENTATION AND SUPPORTING INFORMATION B-6 - PEE DEE FISHES GUILDS B-7 - PEE DEE SUBSTRATE - COVER CORRELATIONS B-8 - SPAWNING AND REARING PERIOD SUMMARY FIGURES B-9 - LIFE HISTORY B-10 - FINAL HABITAT SUITABILITY CURVES

APPENDIX C - TRANSECT DOCUMENTATION C-1 - TRANSECT LOCATIONS, PHOTOS, AND CROSS SECTIONS C-2 - NAVIGATION TRANSECTS C-3 - RIVER MILES



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APPENDIX D - MODEL CALIBRATION D-1 - CALIBRATION DETAILS TABLES D-2 - TRANSECT WEIGHTING METHODS D-3 - TRANSECT WEIGHTING TABLES D-4 - DISCHARGE AND WSE TABLE D-5 - HABITAT DURATION EXPLANATION D-6 - REACHES 2 AND 3 GIS HABITAT MAPS

APPENDIX E - MUSSEL AND NAVIGATION ANALYSIS E-1 - WETTED PERIMETER E-2 - MUSSELS E-3 - NAVIGATION

APPENDIX F - MODEL GRAPHICS-WUA F-1 - ACRONYM TABLE F-2 - DUAL FLOW F-3 - HABITAT DURATION GRAPHS F-4 - WUA GRAPHS

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LIST OF FIGURES

Figure Title Page No. Figure 3-1 Map of the Yadkin-Pee Dee River Basin............................................................. 3-2 Figure 6-1 Longitudinal Profile of the Pee Dee River Instream Flow Study Area. .............. 6-4 Figure 6-2 Reach 1-Subreach 1 Final Transect Locations. ................................................... 6-7 Figure 6-3 Reach 1-Subreach 2 Final Transect Locations. ................................................... 6-9 Figure 6-4 Reach 2-Subreach 1 Approved Transect Locations........................................... 6-11 Figure 6-5 Reach 2-Subreach 2 Approved Transect Locations........................................... 6-14 Figure 6-6 Reach 2-Subreach 3 Approved Transect Locations........................................... 6-15 Figure 6-7 Reach 3-Subreach 1 Approved Transect Locations........................................... 6-16 Figure 6-8 Reach 3-Subreach 2 Approved Transect Locations........................................... 6-18 Figure 6-9 Reach 3-Subreach 3 Approved Transect Locations........................................... 6-19 Figure 8-1 Pee Dee River Navigation Transect No. 9 (Reach 3, Subreach 3) (Old Mill

Dam Weir Site at RM 216.5) Plan View X-Y. .................................................. 8-16 Figure 8-2 Pee Dee River Navigation Transect No. 9 (Reach 3, Subreach 3) (Old Mill

Dam Weir Site at RM 216.5) Profile View X-Y. .............................................. 8-16 Figure 8-3 Navigation Transect No. 9 Stage - Discharge Relationship. ............................. 8-17 Figure 9-1 Example Weighted Usable Area Chart for Some Target Species in the Pee

Dee River. ............................................................................................................ 9-3 Figure 9-2 Pee Dee River Habitat Duration - Reach 2, Subreach 3 - Deep Slow Generic

Lifestage with Cover............................................................................................ 9-5 Figure 9-3 Illustration of the Habitat Duration Interactive Analytical Tool. ........................ 9-8 Figure 9-4 Static Version Example of the Interactive Analytical Tool at 500 cfs Release... 9-9 Figure 9-5 Static Version Example of the Interactive Analytical Tool at 2,000 cfs

Release. .............................................................................................................. 9-10 Figure 9-6 Pee Dee River Reach 2, Subreach 3 Hydro Dual Flow Analysis Deep Fast

Spawn Gravel, Small Cobble............................................................................. 9-11 Figure 9-7 Pee Dee River Reach 2, Subreach 3 Hydro Dual Flow Analysis American

Shad Spawning 3................................................................................................ 9-11 Figure 9-8 Example Static Version of Wetted Perimeter Analysis Tool for the Pee Dee

River. Instream Flow Mussel Study. Note: Water Levels Modeled are 2,000 and 500 cfs. ........................................................................................................ 9-13

Figure 9-9 Pee Dee River navigation and fish passage Transect No. 9 (Reach 3, Subreach 3) (Old Mill Dam Weir Site at RM 216.5) profile view X-Y. ........... 9-14

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LIST OF TABLES

Table Title Page No. Table 1-1 Members of the Pee Dee River Relicensing IFSG. ............................................. 1-7 Table 5-1 Fish Species and Habitat Guild Assignment for the Pee Dee River Instream

Flow Study Revision 2, July 9, 2004. .................................................................. 5-1 Table 5-2 Target Species and Life Stages for Individual HSC Analyses in the Pee Dee

River Instream Flow Study. ................................................................................. 5-3 Table 5-3 Periodicity of Pee Dee River PHABSIM Target Species/Life Stages and

Guilds (Revised March 10, 2005 at the Instream Flow Subgroup Meeting)....... 5-5 Table 6-1 Final Name, Description, and RM Location of the Study Area and Study

Reaches Defined by the Instream Flow Subgroup............................................... 6-2 Table 6-2 Pee Dee River Subreach Sinuosity, Channel Width, and Slope. ......................... 6-4 Table 6-3 Final Reach and Subreach Description Defined by the Instream Flow

Subgroup. ............................................................................................................. 6-5 Table 6-4 Pee Dee River Final PHABSIM Transect Description Reach 1-Subreach 1....... 6-6 Table 6-5 Pee Dee River Final PHABSIM Transect Description Reach 1-Subreach 2....... 6-8 Table 6-6 Pee Dee River Final PHABSIM Transect Description Reach 2-Subreach 1..... 6-10 Table 6-7 Pee Dee River Final Transect Description and Location Reach 2-Subreach 2. 6-13 Table 6-8 Pee Dee River Final PHABSIM Transect Description Reach 2-Subreach 3..... 6-15 Table 6-9 Pee Dee River Final Transect Description and Location Reach 3-Subreach 1. 6-16 Table 6-10 Pee Dee River Final Transect Description and Location Reach 3-Subreach 2. 6-17 Table 6-11 Pee Dee River Final Transect Description and Location Reach 3-Subreach 3. 6-19 Table 7-1 NCDWR Substrate Size Classification and Codes. Modified for the Pee Dee

River by the IFSG. ............................................................................................... 7-3 Table 7-2 NCDWR Cover Type Classification and Codes. Modified for the Pee Dee

River by the IFSG. ............................................................................................... 7-4 Table 7-3 Pee Dee River Meso-Habitat Descriptions. ......................................................... 7-4 Table 7-4 Pee Dee River Habitat Mapping Methods and Information Sources................... 7-6 Table 8-1 Calibration Flows and Model Extrapolations. ..................................................... 8-2 Table 8-2 Target Species, Guilds, and Life Stages Modeled for the Pee Dee River

PHABSIM............................................................................................................ 8-4 Table 8-3 Pee Dee Hydrologic Node Locations................................................................... 8-9 Table 8-4 Life Stages Modeled in the Pee Dee River Dual Flow Analysis. ...................... 8-12 Table 8.5 Peaking Flows and Range of Minimum Flows Chosen for Dual Flow

Analysis. ............................................................................................................ 8-12 Table 8-6 PHABSIM Transects Used for Mussel Analysis on the Pee Dee River. ........... 8-13 Table 8-7 Summary of Navigation Study Site Locations and Assessment Criteria........... 8-14 Table 9-1 Study Site 2 Subreach 3 WUA (sq ft per 1,000 ft) for Some Target Species...... 9-2 Table 9-2 Summary of preliminary flow requirements at navigation study sites for the

Pee Dee River. ................................................................................................... 9-14

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Acronym List Federal/State Agencies Advisory Council on Historic Preservation (ACHP) Federal Aviation Administration (FAA) Federal Energy Regulatory Commission (FERC) National Park Service (NPS) National Marine Fisheries Service (NMFS) National Oceanic and Atmospheric Administration (NOAA) National Resource Conservation Service (NRCS) formerly known as Soil Conservation Service National Weather Service (NWS) North Carolina Department of Natural Resources (NCDNR) North Carolina Department of Environment and Natural Resources (NCDENR) North Carolina Environmental Management Commission (NCEMC) North Carolina Department of Natural and Economic Resources, Division of Environmental Management (NCDEM) North Carolina Division of Parks and Recreation (NCDPR) North Carolina Division of Water Resources (NCDWR) North Carolina Division of Water Quality (NCDWQ) North Carolina Natural Heritage Program (NCNHP) North Carolina State Historic Preservation Officer (NCSHPO) North Carolina Wildlife Resources Commission (NCWRC) South Carolina Department of Natural Resources (SCDNR) South Carolina Department of Health and Environmental Control (SCDHEC) State Historic Preservation Office (SHPO) U.S. Army Corps of Engineers (ACOE) U.S. Department of Interior (DOI) U.S. Environmental Protection Agency (USEPA) U.S. Fish and Wildlife Service (USFWS) U.S. Geological Survey (USGS) U.S. Department of Agriculture (USDA) U.S. Forest Service (USFS) Other Entities Alcoa Power Generating, Inc., Yadkin Division (APGI) Appalachian State University (ASU) Devine Tarbell & Associates, Inc. (DTA) Instream Flow Subgroup (IFSG) Progress Energy (Progress) Robust Redhorse Conservation Committee (RRCC) University of North Carolina at Chapel Hill (UNCCH) Facilities/Places Yadkin - Pee Dee River Project (entire two-development project including both powerhouses, dams and impoundments) Blewett Falls Development (when referring to dam, powerhouse and impoundment) Blewett Falls Dam (when referring to the structure)

Acronym List

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Blewett Falls Hydroelectric Plant (when referring to the powerhouse) Blewett Falls Lake (when referring to the impoundment) Tillery Development (when referring to dam, powerhouse and impoundment) Tillery Dam (when referring to the structure) Tillery Hydroelectric Plant (when referring to the powerhouse) Lake Tillery (when referring to the impoundment) Documents 401 Water Quality Certification (401 WQC) Draft Environmental Assessment (DEA) Environmental Assessment (EA) Environmental Impact Statement (EIS) Final Environmental Assessment (FEA) Initial Consultation Document (ICD) Memorandum of Agreement (MOA) National Wetland Inventory (NWI) Notice of Intent (NOI) Notice of Proposed Rulemaking (NOPR) Preliminary Draft Environmental Assessment (PDEA) Programmatic Agreement (PA) Scoping Document (SD) Shoreline Management Plan (SMP) Laws/Regulations Clean Water Act (CWA) Code of Federal Regulations (CFR) Electric Consumers Protection Act (ECPA) Endangered Species Act (ESA) Federal Power Act (FPA) Fish and Wildlife Coordination Act (FWCA) National Environmental Policy Act (NEPA) National Historic Preservation Act (NHPA) Terminology Alternative Relicensing Process (ALP) Cubic feet per second (cfs) Degrees Celsius (C) Degrees Fahrenheit (F) Dissolved oxygen (DO) Effective Habitat Analysis (HABEF) Feet (ft) Gallons per day (gpd) Geographic Information Systems (GIS) Gigawatt Hour (GWh) Global Positioning System (GPS) Grams (g)

Acronym List

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Habitat duration analysis (HDA) Habitat suitability criteria (HSC) Horsepower (hp) Hydraulic simulation (HYDSIM) module Instream Flow Incremental Method (IFIM) Kilogram (kg) Kilowatts (kW) Kilowatt-hours (kWh) Mean Sea Level (msl) Megawatt (MW) Megawatt-hours (MWh) Meter (m) Micrograms per liter (µg/L) Milligrams per liter (mg/L) Millimeter (mm) Million gallons per day (mgd) National Geodetic Vertical Datum (NGVD) National Wetlands Inventory (NWI) Non-governmental Organizations (NGOs) Ounces (oz.) Outstanding Remarkable Value (ORV) Parts per billion (ppb) Parts per million (ppm) Physical Habitat Simulation Model (PHABSIM) Pounds (lbs.) Power Factor (p.f.) Probable maximum flood (PMF) Project inflow design flood (IDF) Rare, threatened, and endangered species (RTE) Ready for Environmental Assessment (REA) Resource Work Groups (RWG) Revolutions per minute (rpm) Rights-of-way (ROW) Riverine Habitat Simulation (RHABSIM) River mile (RM) Stakeholders (federal and state resource agencies, NGOs, and other interested parties) Technical Work Group (TWG) Volts (V) Water surface elevations (WSE) Water surface elevation/discharge (WSE/Q) Weighted usable area (WUA)

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Section 1 - Pee Dee River Instream Flow Study Report 1.1 Introduction 1.1.1 Study Purpose and Basis Progress Energy is currently relicensing its Blewett Falls and Tillery hydroelectric developments (i.e., Yadkin-Pee Dee Hydroelectric Project No. 2206 [Project]) with the Federal Regulatory Commission (FERC). As part of the relicensing process, Progress Energy established Resource Working Groups (RWG) during May 2003 to identify potential environmental issues associated with Project operations and to develop study plans, as necessary, to evaluate potential Project effects to Project lands and associated lakes and tailwaters. The Water RWG identified the need for an instream flow assessment of the Pee Dee River below the Tillery and Blewett Falls developments (i.e., Progress Energy [2004a], Water RWG Issue No.5, “Evaluate the relationships between Project operations/hydraulics and aquatic habitat, water quality, and fish migrations”). As part of this study process, an Instream Flow Subgroup (IFSG) was formed in May 2003 to develop the appropriate study plan; determine modeling approaches; review modeling input parameters; and provide input on the appropriate instream flow regime to benefit fish and aquatic species for the Project waters. This instream flow study report is part of a comprehensive environmental studies program undertaken by Progress Energy for the FERC relicensing of the Project. The instream flow study was initiated through the formation of the IFSG, which was part of the Water RWG. The IFSG worked specifically on the development of an acceptable instream flow model and related instream flow issues identified during RWG meetings held during May and June of 2003. The IFSG met on a monthly basis from May 2003 to August 2004 to develop the detailed instream flow study plan. The instream flow study plan was finalized by the IFSG during August 2004 (Progress Energy 2004a). Agreement on an Instream Flow Study Plan by the IFSG established Physical Habitat Simulation Model (PHABSIM) as the primary method for quantifying the relationship between streamflow and target species and life stage(s) habitat for all affected stream reaches. Further meetings in the fall of 2004 through 2006 focused on study results, recommended modeling approaches and analytical tools, and evaluation of various instream flow scenarios. The primary goal of the Pee Dee River Instream Flow Study was to assess the effects of river flow regulation on aquatic habitat for fish, mussels, and other aquatic organisms in identified river reaches affected by Progress Energy’s hydroelectric developments on the Pee Dee River. Within each of the instream flow study river reaches identified by IFSG, the study objectives were to define the effects of current Project operations on riverine aquatic habitat and also to explore opportunities for riverine habitat and recreational boating enhancements through alternative Project operating regimes. There are many different instream flow methods available to study and evaluate the effects of changes in stream flow on aquatic habitat. The most widely used and accepted tool is the method developed by the U.S. Fish and Wildlife Service (USFWS) known as the Instream Flow Incremental Method (IFIM). The IFIM technology has evolved as a water planning and management tool (Bovee et al. 1998). Using this method, alternative water release scenarios can be compared and evaluated with reservoir operation and water routing models coupled with habitat duration series

Section 1 Pee Dee River Instream Flow Study Report

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analysis of IFIM. This integrated approach allows resource managers to accommodate temporal and spatial patterns of delivery and regulation by major water projects in a managed river system. The major component of the IFIM is the PHABSIM. PHABSIM is a collection of hydraulic and habitat simulation models designed to quantify the relationship between stream flow and target species habitat. The combination of channel geometry, simulated distribution of depth and velocities, and habitat suitability criteria (HSC) reveals the relationship between stream flow and available habitat for each target species (Bovee et al. 1998). 1.1.2 Resource Management Goals for the Pee Dee River Pertinent to the Instream

Flow Study Specific resource management goals were identified by the North Carolina Wildlife Resources Commission (NCWRC), North Carolina Department of Wildlife Resources (NCDWR), and the South Carolina Department of Natural Resources (SCDNR) during the IFSG meetings. These management goals are listed below(NCWRC 2005; SCDNR 2004). For additional details on management plans for select species, reference Appendix A-2 - Pee Dee IFIM Study Plan-Section 1. ■ North Carolina Wildlife Resources Commission Management Objectives - The

management goal of the North Carolina Department of Natural Resources (NCDNR) is to protect, conserve, and enhance the aquatic resources of the Great Pee Dee River. The following management objectives have been developed to achieve the goal: 1. Improve and restore American shad populations and habitat in the river reaches below

the Blewett Hydroelectric Development and evaluate restoration potential between Blewett and Tillery Hydroelectric Developments

2. Improve the robust redhorse population and habitat in the river reach below the Blewett Hydroelectric Development.

3. Improve the Carolina redhorse population and habitat in the river reach below the Tillery Hydroelectric Development.

4. Improve habitat conditions for coastal stock of striped bass in Reach 2 located below the Blewett Hydroelectric Development.

5. Enhance habitat conditions for white bass spawning below the Tillery Hydroelectric Development.

6. Improve American eel populations in the river reaches below the Blewett and Tillery Hydroelectric Developments.

7. Shortnose sturgeon and Atlantic sturgeon spawning habitat improvement in Reach 2 located below the Blewett Hydroelectric Development (NCWRC will defer to USFWS/National Marine Fisheries Service [NMFS]/NCWRC/SCDNR diadromous fish restoration plan for the river basin).

8. Improve habitat for resident fish species that are rare mussel hosts (e.g., darter and minnow species) in both river reaches.

9. Improve habitat for rare mussel species present in both river reaches. 10. Enhance access to the river by fishermen and ensure that sufficient stream flow is

present to facilitate recreational navigation.


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■ South Carolina Department of Natural Resources Pee Dee River Fishery Management Objectives - The management goal of the SCDNR is to protect, conserve, and enhance the aquatic resources of the Great Pee Dee River. The following management objectives have been developed to achieve the goal: 1. Restore, enhance, and protect instream habitat for all native fish and invertebrate species

in the river. Important habitat components include water depth and velocity, substrate, cover, and water quality.

2. Restore a more natural flow regime in the river that is beneficial to a high diversity of native aquatic organisms.

3. Ensure that sufficient water depth and velocity are present to facilitate successful migration and spawning of diadromous fish species including Atlantic sturgeon, shortnose sturgeon, American shad, blueback herring, hickory shad, striped bass, and American eel, and other migratory species such as striped bass, robust redhorse, and Carolina redhorse.

4. Prevent the further introduction of non-native invasive aquatic plant and animal species. 5. Enhance access to the river by fishermen and ensure that sufficient stream flow is

present to facilitate recreational navigation. 6. Conduct periodic surveys of the fish community to establish baseline conditions and

evaluate spatial and temporal changes. 7. Work within the established regulatory and environmental review process to ensure that

development, construction, and alteration activities in and along the river do not significantly impair aquatic habitat.

8. Encourage the protection of vegetated riparian buffers of at least 100 ft in width along the river and at least 50 ft in width along tributary streams.

9. Seek to minimize the removal of fallen trees and other debris that provide significant aquatic habitat without impeding river navigation.

10. Encourage the South Carolina Department of Health and Environmental Control (SCDHEC) and U.S. Environmental Protection Agency (USEPA) to enforce provisions of the State Pollution Control Act and Federal Clean Water Act in the river and its tributaries.

11. Encourage the development and implementation of Best Management Practices to prevent non-source pollution for all land disturbing activities in the Pee Dee River Basin.

12. Encourage the implementation of water conservation practices by all water users in the Pee Dee River Basin.

The USFWS, in coordination with the NMFS, NCWRC and SCDNR, have drafted a diadromous fish restoration plan for the Yadkin-Pee Dee River Basin (USFWS et al. 2006). This plan identifies specific restoration goals for diadromous fish populations in the river basin. Specific elements of this plan address habitat enhancement goals for diadromous fish species throughout the river basin. Subgroup members also identified other pertinent management plans. These plans include: ■ Final recovery plan for the shortnose sturgeon (NMFS 1998); ■ Atlantic States Marine Fisheries Commission management plans for migratory fish species

(Stirratt et al. 1999; Stirratt et al. 2000a; Stirratt et al. 2000b; Beal et al. 2000);


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■ Robust Redhorse Conservation Committee (RRCC) conservation goals for robust redhorse (RRCC Yadkin-Pee Dee Technical Work Group [TWG] 2002; Nichols 2003);

■ Pee Dee National Wildlife Refuge Management Plan (USFWS 2004); ■ South Carolina instream flow standards for recreational boating navigation and other uses (de

Kozlowski 1988); ■ South Carolina instream flow studies: a status report. Minimum instream-flow policy,

determination of general instream-flow recommendations, and impoundments: instream-flow concerns and effects and downstream fisheries (Bulak and Jöbsis 1989);

■ Instream flow study. Phase II: Determination of minimum flow standards to protect instream flow uses in priority stream segments. A report to the South Carolina General Assembly. South Carolina Water Resources Commission, Columbia, South Carolina, Report Number 163, May 1988 (de Kozlowski 1988);

■ North Carolina water quality assessment and impaired waters list (2002 integrated 305(b) and 303(d) report). Final. February, 2003. North Carolina Department of Environment and Natural Resources, Division of Water Quality, Water Quality Section-Planning Branch, Raleigh, North Carolina (NCDWQ 2003a);

■ Yadkin-Pee Dee River Basinwide Water Quality Plan. March 2003. North Carolina Department of Environment and Natural Resources, Division of Water Quality, Water Quality Section Planning Branch, Raleigh, North Carolina (NCDWQ 2003b); and

■ Watershed water quality assessment: Pee Dee Basin. March 2001. South Carolina Department of Health and Environmental Control, Columbia, South Carolina (SCDHEC 2001).

1.1.3 Pee Dee River Instream Flow Study Objectives During RWG consultations, all parties agreed that the instream flow issue would be best addressed by a holistic approach that considered all flow-related interests of stakeholders. Since the utilization of water resources of the Yadkin-Pee Dee River involves multiple, competitive interests, stream flow issues for the Progress Energy projects and any resulting studies must consider and integrate the wide range of interests and uses. Accordingly, the instream flow studies incorporate a broad approach for evaluating the various flow issues for Progress Energy Project and are designed to collect much of the necessary information to make sound, reasonable stream flow decisions. The evaluation of instream flows also draws upon the results of other models and studies addressing physical parameters such as temperature, dissolved oxygen, and CHEOPS™ (hydroelectric operations and planning model developed by Devine Tarbell & Associates, Inc. [DTA]), RMS4 (River Modeling System Version 4 developed by Tennessee Valley Authority), Oasis (hydroelectric operations and planning model developed by Hydrologics, Inc.), and biological and water quality studies that describe the aquatic biological communities and associated environmental conditions. The Instream Flow Study Plan (Progress Energy 2004) is included in Appendix A-2 of this report. The study plan was developed in consultation with the IFSG, and states the following study objectives: 1. Enhance the existing flow regime, where necessary, to restore, enhance, and/or protect the

native fishes and macroinvertebrates by addressing the major physical components of riverine


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habitat — water velocity, depth, substrate, and cover — for those focus species or species guilds identified by the IFSG. a. Identify and evaluate key native fish and macroinvertebrate species and/or habitat guilds

which will be used as the basis for instream assessments of native fauna. The identification process must include readily available and acceptable habitat suitability index (HSC) criteria (i.e., depth, velocity, substrate, and cover) and consider seasonal variability in habitat requirements and life stage.

b. Determine the quantifiable effects of Project operations on aquatic habitat by evaluating the existing flow regime and any recommended future flow regimes. Perform these analyses in the context of the current Project operation (baseline condition) unregulated flow (with existing development in place) and alternative future operating scenarios, based on habitat versus flow analysis, habitat time series analysis, wetted perimeter analysis, and unsteady state peaking flows over a specified period of record with the aid of Project operation modeling and basin-wide hydrologic simulation.

2. Enhance the existing flow regime, where necessary, to promote successful passage, migration, spawning, and rearing of diadromous fish species. a. Key species of interest and study are American shad, Atlantic sturgeon, shortnose

sturgeon, blueback herring, and striped bass (coastal population). The study will focus on flow-related habitat for spawning, incubation, nursery, and juvenile life stages. The American eel is also a diadromous species of concern; however, its habitat requirements are broad and well represented by the key species and guilds listed above.

b. Ensure sufficient water depth and velocities for successful upstream migration and spawning of key diadromous species.

c. Identify critical habitat areas for spawning and incubation of key diadromous species and include these areas in instream flow study sites. Based on present, best available information, these sites include: i. Reach 1, Cashua Ferry Landing (shortnose sturgeon) ii. Reach 1, Blues Landing (Atlantic sturgeon, shortnose sturgeon) iii. Reach 2, Jones Creek (American shad, striped bass) iv. Reach 2, Big Island (American shad, striped bass) v. Reach 3, Tillery Dam to Rocky River (American shad)

3. Enhance the existing flow regime, where necessary, to restore and/or protect identified rare fish and mussel species by addressing the major physical components of riverine habitat —water velocity, depth, substrate, and cover. a. Key fish species of interest are shortnose sturgeon, Atlantic sturgeon, robust redhorse,

and Carolina redhorse. Key mussel species of interest are yellow lampmussel (Lampsilis cariosa), alewife floater (Anodonta implicate), Eastern lampmussel (Lampsilis radiata radiata), Eastern pondmussel (Ligumia nasuta), and Roanoke slabshell (Elliptio roanokensis), and known fish host species.

b. Identify critical habitat areas for rare, threatened, and endangered (RTE) species inhabitation (adults and juveniles), spawning, and egg/larvae rearing and include identified areas in instream flow study sites. Based on present, best available information, these sites include: i. Reach 1, Cashua Ferry Landing (shortnose sturgeon) ii. Reach 1, Blues Landing (robust redhorse, Atlantic sturgeon, shortnose sturgeon) iii. Reach 2, Jones Creek shoal (robust redhorse, Carolina redhorse, mussels)


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iv. Reach 2, Hitchcock Creek shoal (robust redhorse) v. Reach 2, Big Island shoal (robust redhorse, Carolina redhorse, mussels) vi. Reach 3, (Carolina redhorse, mussels)

4. Ensure flows support priority resident fish management goals. a. Enhance the existing flow regime, where necessary, to promote the white bass and

resident striped bass population and sport fishery in the Pee Dee River reach below Lake Tillery Dam.

b. Explore opportunities for flow regimes that favor native over non-native species (e.g., smallmouth buffalo, flathead catfish, blue catfish, and grass carp).

5. Ensure flow regimes that support state water quality standards in river reaches, where directly applicable to power plant operations. a. Consider effects of alternative flow regimes on downstream water quality, particularly

dissolved oxygen concentrations relative to current flow regime and any recommended future flow regime alternatives.

6. Ensure flows are adequate to facilitate recreational boating in identified river reaches. a. Ensure South Carolina and North Carolina navigational criteria are met with regard to

one-way or two-way navigation, where applicable in the identified reaches. During the study, several of the following areas will be selected to evaluate navigation at different flow levels. The specific selected areas to evaluated were chosen during field site visits in 2004 with SCDNR and NCDWR personnel. i. South Carolina identified critical navigation areas are:

(1) Upstream of Cashua Ferry boating access area at S.C. Highway 34 (2) Upstream of Tom Blue’s boating access area at gravel bar in river bend (3) Upstream of Weyerhaeuser paper mill at gravel bar (alternative site is

confluence of Thompson Creek below Cheraw boat landing) (4) Shoal just above U.S. Highway 1/S.C. Highway 9 at Cheraw (5) Step/prehistoric fishing weir at upstream end of Great Island (6) Shallow run at foot of Buchanan Shoals

ii. North Carolina proposed critical navigation areas are: (1) Shoal and old dam site below Tillery Dam (2) Buzzard Island shoal and prehistoric fishing weir (3) Prehistoric fishing weir just above Rocky River confluence (4) Shoal at Blewett Falls headwaters (5) Big Island shoal (6) Hitchcock Creek shoal at prehistoric fishing weir (7) Jones Creek shoal (downstream ledge) (8) Shallow run at foot of Buchanan Shoals. North Carolina will apply one-

way and two-way navigation criteria, similar to South Carolina, to the following river reaches. Blewett Dam to North Carolina-South Carolina state line: one-way navigation, except for the stretch from Blewett Dam public boating access area to U.S. Highway 74 public boating access area, which is two-way; Tillery Dam to N.C. Highway 109 Bridge public boating access area: one-way navigation; and N.C. Highway 109 public boating access area to Blewett Falls Lake: two-way navigation


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1.1.4 Previous License Conditions on Instream Flow The Blewett Falls and Tillery Developments were last issued a FERC license in 1958, permitting their operation for 50 years. The license requires a continuous release of 40 cfs at the Tillery Development. The required continuous release at the Blewett Falls Development is 150 cfs at Blewett Falls, as recorded at the U.S. Geological Survey (USGS) gage near Rockingham, North Carolina. 1.1.5 Consultation Instream flow studies were conducted under the purview of the IFSG. Members of the IFSG included the Licensee and its consultant, DTA, state and federal resource agencies, resource conservation non-governmental organizations (NGOs), and Alcoa Power Generating, Inc. (APGI) and its consultants (Longview Associates and Entrix). APGI is the owner and operator of the Yadkin Hydroelectric Project (No. 2197), located upstream of Progress Energy’s Project. While many contributed to the instream flow study, the primary members of the IFSG and their respective representatives are listed in Table 1-1. The IFSG held in-office and on-site meetings and conferred by telephone and email throughout the study period to discuss and agree on study design protocol, field methods, and modeling and analysis methods. The documentation of these communications is provided in Appendix A-3 - Summaries of Consultation. Table 1-1 Members of the Pee Dee River Relicensing IFSG.

Member Representative Progress Energy (Licensee) Phil Lucas John Crutchfield Progress Energy Consultant (DTA) John Devine Steve Arnold Michael Barclay APGI Gene Ellis APGI Consultant acting on behalf of APGI (Longview Associates & Entrix)

Wendy Bley (Longview Associates)

Paul Leonard (Entrix) Eric Dilts (Entrix) North Carolina Division of Water Resources Steve Reed Jim Mead North Carolina Wildlife Resources Commission Todd Ewing Chris Goudreau South Carolina Department of Natural Resources Danny Johnson South Carolina Department of Health and Environmental Control Dick Christie South Carolina Coastal Conservation League and American Rivers Gerritt Jöbsis The Nature Conservancy, South Carolina Eric Krueger U.S. Fish and Wildlife Service John Ellis Mark Bowers National Marine Fisheries Service Prescott Brownell


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1.1.6 Report Organization and Purpose This report is divided into two primary sections; the main body and the appendices. Because of the large volume, detailed graphics, and intricacies of the technical data, the appendices are provided in electronic format on a CD located at the back of this report. In the main body of this report, the reader is referred to the Appendices where necessary. Because there are two hydroelectric developments (i.e., Blewett Falls and Tillery developments) with both separate and overlapping effects, this report is organized such that both common and unique effects are completely covered with the least redundancy. This is a technical report to be used by the License (Progress Energy), IFSG, relicensing stakeholders, and FERC to evaluate the effects of hydro project flow regulation on aquatic resources in the Pee Dee River. It is important for those using the report to recognize that the result of an instream flow study is not a set value, but a model simulating a range of values to be used as a tool in concert with other tools to evaluate Project operations and stream flow or a set of stream flow alternatives with enhancement potential. This report does not promote one project operation mode versus another or one flow or set of flows versus another. This report documents the development of the instream flow model, presents the results, and illustrates how the results might be used by the IFSG and other stakeholders to evaluate the effects of flow alternatives on aquatic habitat. It should also be noted that any flow recommendations for the Project are dependent upon instream flow releases from the upstream Yadkin Project owned and operated by APGI.

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Section 2 - General Concepts of PHABSIM The PHABSIM is based on the premise that stream-dwelling fishes prefer a certain range of depths, velocities, substrates, and cover types, depending on the species and life stage, and that the availability of these preferred habitat conditions varies with stream flow. The PHABSIM is designed to quantify potential physical habitat available for each life stage of interest for a target fish species at various levels of stream discharge, using a series of computer programs developed by the USFWS (Bovee 1982). A natural stream contains a complex mosaic of physical features in different combinations. One area, such as a riffle, may be shallow and fast-moving over a substrate of cobble and gravel and no cover while another area, such as a pool, may be deep and slow-moving over a substrate of silt, with a large root wad along the shore. One fish species may find the riffle desirable while another species may prefer the pool; a third species may not prefer either. It is also common for a fish species to prefer different habitats during its different life stages. For example, a species might prefer a riffle for spawning and another habitat, such as a pool with cover, for feeding, resting, or hiding. These different habitat types (e.g., pools, riffles, runs, and glides) are known as “meso-habitats.” A fish species or life stage prefers a particular meso-habitat type because its “micro-habitat” characteristics of depth, velocity, substrate, and cover are generally within its preferred range. For example, a trout prefers faster water with a rocky substrate, such as a boulder run, while a common carp prefers slower water with a silt or mud substrate, such as a pool. These micro-habitat conditions of depth and velocity are not static in the environment; they vary due to changes in climatic conditions such as water flow and anthropogenic effects such as operation of the hydroelectric project. Too much or too little flow through the riffle or pool may push the velocities and depths outside the preferred limits or tolerances of a particular species or life stage. Using PHABSIM, the availability of preferred microhabitat conditions at any given flow can be modeled for instream flow decision making. In the field, microhabitat parameters of depth, velocity, substrate, and cover are measured at numerous points across the channel and at a number of locations along the length of the river. Each discrete location along the river where the measurements are collected are called transects. Each transect is placed on a different habitat type. Depth, velocity, substrate, and cover measurements are made at close intervals along the transect, usually 1 to 3 ft apart. A group of transects is selected to represent a particular reach of river that is generally homogeneous in channel size, slope, and discharge. All flow and water surface elevation measurements are usually taken at the same transect locations at selected low-, medium-, and high-flow releases. The range of flow releases takes into account the hydraulic release operating range of the hydroelectric plant and natural flow variability. The PHABSIM model uses these measurements to predict habitat availability at flows other than those measured in the field. Major components of the PHABSIM methodology include: ■ Development of study objectives; ■ Study area and study reach designation; ■ Habitat mapping; ■ Transect selection; ■ Transect weighting;

Section 2 General Concepts of PHABSIM

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■ Field collection of hydraulic and channel data; ■ Selection of target species/life stage and development or verification of HSC; ■ Hydraulic simulation to determine the spatial distribution of combinations of depths and

velocities with respect to substrate and cover under a variety of discharges; and ■ Habitat simulation using HSC to generate an index of change in habitat relative to change in

discharge. The product of the habitat simulation is expressed as Weighted Usable Area (WUA) for a range of simulated stream discharges. WUA is the building block upon which other analyses depend, including the habitat duration analyses and the effective habitat analyses, among others. Analyses completed for the Pee Dee River Instream Flow Study are as follows: WUA, habitat duration, effective habitat analyses, navigation analysis, and wetted perimeter analysis (mussel evaluations only).

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Section 3 - Project Location, Description, and Operation 3.1 Tillery Development 3.1.1 Location The Tillery Development is located at river mile (RM) 218 in Montgomery and Stanly Counties, four miles west of Mount Gilead, North Carolina (Figure 3-1). The Tillery impoundment (known as Lake Tillery) extends upstream to the tailrace of the Falls Development powerhouse, which is owned and operated by APGI. Construction of the Tillery Development began in 1926. In the spring of 1928, Tillery was completed and the plant was placed in service. 3.1.2 Description The Tillery Dam consists of approximately 1,200 ft of earthen embankment and 1,550 ft of concrete structures. The spillway at Tillery is controlled by 18 tainter gates, each 34 ft wide by 24 ft high. Six of the tainter gates can be partially operated remotely from the powerhouse control room. The other gates can be operated by controls located at the gates on the spillway deck. A 14-ft-wide trash gate is located between the intake and spillway. The Tillery powerhouse is a concrete, semi-outdoor integral structure containing four generating units, each with its own penstock and headgates. The turbine discharge exits directly into the Pee Dee River with a gross head of 72 ft. The turbines at the Tillery Development consist of three Francis turbines and one fixed-blade propeller turbine. Units 1 and 3 are Francis-type turbines rated at 31,100 hp with a discharge capacity of 4,456 cfs. Unit 2 is also a Francis-type turbine, but is rated at 25,600 hp with a discharge capacity of 3,627 cfs. Unit 4 is a fixed-blade propeller-type rated at 33,000 hp with a discharge of 5,145 cfs. The auxiliary turbine is a Leffel vertical Francis turbine rated at 650 hp with a discharge of 100 cfs. The Tillery Dam creates the impoundment known as Lake Tillery. The impoundment extends approximately 15 miles to the tailwaters of APGI’s Falls Development. At the normal maximum operating elevation of 277.3 ft1, Lake Tillery is approximately 72 ft deep at the dam and has a reservoir surface area of approximately 5,697 acres. The lake serves as a municipal drinking water source for the City of Norwood and Montgomery County. The lake is also used by the public for boating, fishing, and other recreational activities. The lake has a shoreline length of approximately 118 miles (Carolina Power & Light [CP&L] 2001a). Approximately 55 percent of the shoreline is residential or commercial development.

1 NAVD 88 datum. Unless otherwise noted, all data are NAVD 88 datum. The NAVD 88 datum is 0.9 ft lower than

the 1929 NGVD datum (NAD 29).

Section 3 Project Location, Description, and Operation

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Figure 3-1 Map of the Yadkin-Pee Dee River Basin.


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The intake structure for the Norwood Water Treatment Plant is located on the west shoreline, and the intake pipe itself is approximately 25 ft below the normal reservoir elevation at 252.3 ft. There are two intakes on the east shoreline for the Montgomery County Water Treatment Plant, but only one intake is used at any one time. The lower intake pipe, located at elevation 255 ft or 22 ft below the normal reservoir surface elevation, can be operated if the lake level is too low to use the upper intake. 3.1.3 Operations The Tillery Development is operated as a peaking and load-following facility. Typical operations includes daily (weekday) generation and load-following during hours of peak demand with scheduling and output varying seasonally based on peak electrical demand and water availability. The inflows into the Tillery Development consist primarily of the outflow from APGI’s Falls Development coupled with inflow from the Uwharrie River. Approximately six percent of the average annual inflow comes from the Falls Development while the Uwharrie River provides 94 percent of the average annual inflow. APGI provides information to Progress Energy on the expected daily plant generation and discharge of the Yadkin Project. Specific information is also provided by APGI on water levels and inflows to High Rock Lake. Progress Energy’s license allows drawdowns at Lake Tillery of up to 22 ft below full pond. Over the past several years, Progress Energy has voluntarily made its best efforts to operate Lake Tillery within a 4-ft range under normal conditions, and much of the time operates within a 2-ft range except during periods of maintenance, when Progress Energy draws Lake Tillery down approximately 12 ft. There is also an informal agreement with the NCWRC to maintain Lake Tillery levels during the period of April 15 to May 15 within approximately 1 ft of full pond to facilitate largemouth bass spawning. Outflows from the Tillery Development flow into Blewett Falls Lake after passing through a 19-mile reach of the Pee Dee River. Under normal operating conditions, it takes approximately eight hours for releases from the Tillery Development to be observed at the Blewett Falls powerhouse. 3.2 Blewett Falls Development 3.2.1 Location The Blewett Falls Development is located approximately 16 miles upstream of the North Carolina-South Carolina state border at RM 188.2 (Figure 3-1). The powerhouse contains six turbine-generator units. The Blewett Falls Development was brought into service in June 1912. 3.2.2 Description The Blewett Falls Dam is a 3,168-ft-long structure consisting of a 1,700-ft-long earthen embankment and a 1,468-ft-long concrete spillway and abutments. The concrete crest elevation is 173.2 ft which is topped by 4 ft of flashboards. The normal maximum pond elevation is 177.2 ft.


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The Blewett Falls powerhouse contains six horizontal-shaft double-runner “camel back” turbines each with its own penstock and governor. Units 1, 2, and 3 are rated at 5,350 hp with a discharge capacity of 1,351 cfs each. Units 4, 5, and 6 are rated at 6,400 hp with a discharge capacity of 1,715 cfs. The Blewett Falls Dam creates the Blewett Falls Lake impoundment. At normal maximum pool elevation, the reservoir extends approximately 11 miles upstream. The surface area of the lake at the normal maximum operating pool is approximately 2,866 acres. The Blewett Falls shoreline is largely undeveloped. The lake is available to the public for boating, fishing, and other recreation activities. There are two municipal water supply intakes in the reservoir, one serving Anson County and the other serving Richmond County. 3.2.3 Operations The Blewett Falls Development is operated as a “block-loaded” facility; the units are either operated at best efficiency or are not operated at all. The hydraulic capacity of Blewett Falls is significantly less than Tillery; therefore, the Blewett Falls Development must anticipate flows from Tillery generation and begin generating in advance of flows reaching the lake. This can result in a daily reservoir fluctuation of up to 3 ft. This also serves as a means to regulate peaking flows from Tillery using the Blewett Falls Lake storage to reduce discharge fluctuations and minimize spill at the dam. This operation is consistent year-round and varies only with seasonal availability of water. For more detail on the operational characteristics of the two developments, please refer to Exhibits A and B of the Yadkin-Pee Dee Project Final Application for License.

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Section 4 - Project Area Description 4.1 The Yadkin-Pee Dee River Basin The Yadkin-Pee Dee River originates near the town of Blowing Rock and flows northeast for approximately 100 miles from the Blue Ridge Mountains into the Piedmont physiographic (Figure 3-1). Flow is regulated in the Yadkin-Pee Dee River Basin by six mainstem hydroelectric developments. A growing urban area extends from Charlotte to Raleigh-Durham and is known as the “Piedmont Crescent” (Appalachian State University [ASU] 1999). South of the Piedmont Crescent, the river enters the Uwharrie Lakes Region, named for the chain of six reservoirs located along this reach of the Yadkin-Pee Dee River. Two of these reservoirs are formed by dams that constitute Progress Energy’s Yadkin-Pee Dee Hydroelectric Project; namely, Tillery (RM 218) and Blewett Falls (RM 188) developments. The Uwharrie River joins the Yadkin River at the upper end of Lake Tillery to form the Pee Dee River. There are approximately 19 miles of free-flowing river between Tillery Dam and the upper reaches of Blewett Falls Lake. The Pee Dee River flows southeast from Blewett Falls Lake for approximately 188 miles through the lower Piedmont of North Carolina and coastal plain of South Carolina (Figure 3-1). Open farmland, stands of hardwood and pine, and bottomlands/swamp dominate the landscape prior to the river entering the Atlantic Ocean through Winyah Bay at Georgetown, South Carolina. 4.2 Climate The climate of the Project area is typical for the southeast U.S. The average annual air temperature recorded in Wadesboro, located at the base of Blewett Falls Lake, is 60.9°F, with a daily average maximum of 72.0°F and daily average minimum of 49.8°F. Average annual precipitation is 47.04 inches (U.S. Department of Agriculture [USDA] 2002 Natural Resources Conservation Service [NRCS] website). 4.3 Physiography The Project area is located in the Uwharrie Lakes region, in North Carolina’s central Piedmont. This region consists of rolling hills accentuated by the Uwharrie Mountains, one of the oldest mountain ranges in North America (Yadkin-Pee Dee Lakes Project website 2002). The Uwharrie Mountains are aligned northeast to southwest and reach up to approximately 1,000 ft elevation (USDA 2001). 4.4 Hydrography The Yadkin-Pee Dee River, the second largest basin in North Carolina, drains a total area of 7,213 square miles at the North Carolina-South Carolina state line. There are approximately 5,991 linear miles of freshwater streams and rivers (NCDWQ 1998). The Yadkin-Pee Dee River drains an area of approximately 6,839 square miles upstream of the Blewett Falls Development, and the drainage area at Tillery is approximately 4,600 square miles. The major tributaries located in the Project area include the Uwharrie, Rocky, and Little Rivers. The Yadkin River becomes the Pee Dee River at the confluence with the Uwharrie River (Figure 3-1).

Section 4 Project Area Description

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The Uwharrie River flows southward from its headwaters near Trinity, North Carolina, in northwestern Randolph County, through the Uwharrie National Forest. The Uwharrie River empties into the Yadkin River below Falls Dam, at which point the mainstem becomes the Pee Dee River. The drainage area of the Uwharrie River is approximately 373 square miles, comprising 5.5 percent of the total drainage area at Blewett Falls Dam. The Rocky and Little Rivers which enter the Pee Dee River between Tillery Dam and the upper reaches of Blewett Falls Lake are located outside of the Project boundary. The Rocky River is located on the western side of the Pee Dee River and flows generally east-southeast from its headwaters near the junctures of Iredell, Davidson, and Cabarrus Counties, about 30 miles northeast of Charlotte, North Carolina. The Rocky River and its tributaries drain in an eastern direction, joining the Pee Dee River approximately four miles south of Tillery Dam. The drainage area for Rocky River is approximately 1,457 square miles, comprising 21 percent of the total drainage area at Blewett Falls Dam. The Rocky River is unregulated and tends to be subject to rapid and significant changes in flow. The Little River is located on the eastern side of the Pee Dee River, and flows south from its headwaters near Asheboro, North Carolina, in Randolph County. The Little River empties into the Pee Dee River in Richmond County, just upstream of Blewett Falls Lake. A series of small, low-head impoundments are located on the Little River upstream of the confluence with the Pee Dee River. The drainage area for the Little River is 354 square miles, comprising five percent of the total drainage area at Blewett Falls Dam. 4.5 Land Use The Pee Dee River is primarily located in a rural farming region characterized by rolling hills, with much of the land immediately adjacent to the Project managed for timber or agricultural use. However, this is one of the most rapidly developing regions in the country as approximately 18 percent of North Carolina’s population lives within the basin (NCDWQ 1998). The region’s population centers are located along U.S. Interstate Highways I-85 and I-40, extending from Charlotte to the Raleigh-Durham area. There are a number of smaller towns and communities in South Carolina located along the lower Pee Dee River, the largest of which are Cheraw and Florence. Numerous commercial and industrial facilities are located in proximity to these municipalities along or near the Pee Dee River and use the river as a source of water and for discharge of wastewater. 4.6 Water Uses The Yadkin-Pee Dee River is utilized in many ways including power generation, municipal and industrial water supply, wastewater discharge, irrigation, water-based recreation, and fish and wildlife habitat. Over time, with the increased population associated with the growth of the “Piedmont Crescent” and the development of shorefront homes and associated infrastructure and businesses in the Uwharrie Lakes region, the use of water for water-based recreation activities and municipal and industrial water supplies has increased. There are four municipal water intakes within

Section 4 Project Area Description

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the Project boundaries of Tillery and Blewett Falls Developments, but water from Tillery and Blewett Falls Lakes is used primarily for power generation. Downstream from the Project, the Pee Dee River flows approximately 15 miles to where it enters South Carolina. Much of the area in South Carolina is rural; however, the Pee Dee River is important to municipalities and industries alike as a source of water and for receiving treated wastewater. The major municipalities that utilize the Pee Dee River include Bennettsville, Cheraw, Florence, and the Grand Strand Water and Sewer Authority. Industries and commercial development in proximity to the river are located primarily in the areas near Cheraw, Bennettsville, Society Hill, and Florence.

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Section 5 - Affected Species, Periodicity, and Habitat Suitability Criteria

5.1 Selection of Target Species and Habitat Guilds The IFSG selected a combination of target species and guilds to be modeled in PHABSIM from a list of species known to be present in the study area (Table 5-1). The list of species was based on results of fish surveys conducted throughout the study area by Progress Energy, the NCWRC, and SCDNR. Please refer to Exhibit E4, Report on Fish and Aquatic Resources, of the Progress Energy Final License Application for a complete synopsis of fishery resources in the Pee Dee River. Table 5-1 Fish Species and Habitat Guild Assignment for the Pee Dee River Instream

Flow Study Revision 2, July 9, 2004. Habitat Types and Guilds1, 2, 3

Scientific Name Common Name Shallow Slow

Shallow Fast

Deep Slow

Deep Fast

Petromyzontidae Lampreys Petromyzon marinus sea lamprey A Acipenseridae Sturgeons Acipenser oxyrinchus Atlantic sturgeon S Acipenser brevirostrum shortnose sturgeon S Lepisostedidae Gars Lepisosteus osseus longnose gar A, J A, J, S Amidae Bowfin Amia calva Bowfin A, S Anguillidae Freshwater eels Anguilla rostrata American eel J A, J J Clupeidae Herrings Dorosoma cepidianum gizzard shad A, J A, J, S Dorosoma petenense threadfin shad A, J A, J, S Alosa mediocris hickory shad J, S Alosa sapidissima American shad J J, S Alosa aestivalis blueback herring J, S Cyprinidae Carps and Minnows Cyprinus carpio common carp J, S A, J, S Notemigonus crysoleucas golden shiner A, J, S A, J, S Hybognathus regius Eastern silvery minnow J, S A, J, S Nocomis leptocephalus bluehead chub A, S Cyprinella analostana satinfin shiner A, J, S A, J, S Cyprinella nivea whitefin shiner A, J S A Cyprinella pyrrhomelas fieryblack shiner A, J S A Notropis altipinnis highfin shiner J, S A Notropis amoenus comely shiner A, J S A, J Notropis hudsonius spottail shiner A, J S A, J Notropis petersoni coastal shiner A, J S A Notropis scepticus sandbar shiner A, J S A Catostomidae Suckers Catostomus commersoni white sucker J S A, J A Minytrema melanops spotted sucker J S A Scartomyzon spp. brassy jumprock J S A A Moxostoma macrolepidotum shorthead redhorse J S A A4 Moxostoma anisurum notchlip redhorse J S A, J

Section 5 Affected Species, Periodicity, and Habitat Suitability Criteria

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Habitat Types and Guilds1, 2, 3 Scientific Name Common Name Shallow

Slow Shallow

Fast Deep Slow

Deep Fast

Moxostoma robustum robust redhorse S A, J Moxostoma sp. Carolina redhorse S A, J Carpiodes cyprinus quillback S A S Erimyzon oblongus creek chubsucker S A, J, S Carpiodes velifer highfin carpsucker S A S Ictiobus bubalus smallmouth buffalo J A A, S A Ictiobus cyprinellus bigmouth buffalo A Ictaluridae North American catfishes Ictalurus punctatus channel catfish A, J J Ictalurus furcatus blue catfish A, S A Ameiurus catus white catfish A A, J Ameiurus brunneus snail bullhead A Ameiurus nebulosus brown bullhead A Ameiurus platycephalus flat bullhead A Pylodictis olivaris flathead catfish J A, J, S Esocidae Pikes Esox americanus americanus redfin pickerel A, J, S Esox niger chain pickerel A, J, S Umbridae Mudminnows Umbra pygmaea Eastern mudminnow A, J, S Poeciliidae Livebearers Gambusia holbrooki Eastern mosquitofish A, J, S Aphredoderidae Pirate perches Aphredoderus sayanus pirate perch A Atherinidae Silversides Labidesthes sicculus brook silverside A Moronidae Temperate basses Morone americana white perch J S A, J S Morone chrysops white bass J S A, J S Morone saxatilis striped bass A, S Centrarchidae Sunfishes Lepomis auritus redbreast sunfish J, S A, J, S Lepomis cyanellus green sunfish A, J, S Lepomis gibbosus pumpkinseed J, S A, J, S Lepomis macrochirus bluegill J, S A, J, S Lepomis microlophus redear sunfish A, J, S Lepomis punctatus spotted sunfish A, J, S Micropterus salmoides largemouth bass J, S A, J, S Pomoxis nigromaculatus black crappie A, J, S Percidae Perches Etheostoma olmstedi tessellated darter A, J S A Percina crassus Piedmont darter A, S Perca flavescens yellow perch A, J, S

1 Habitat types based on predominant habitat types present in the Pee Dee River derived from the aerial videography study.

2 Life stages: A = adult; J = juvenile, including young of year; S = spawning. 3 Classification of species and life stages into habitat types based on Becker (1983), Hamilton and Nelson (1984),

Aadland et al. (1991), Jenkins and Burkhead (1994), Rhode et al. (1994), Leonard and Dilts (2003), and Progress Energy (2003).


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For guilds, the IFSG grouped species/life stages according to generally similar habitat preferences. A guild approach was deemed necessary due to the diverse assemblage of species and habitat types encountered in the river reaches and the transitional nature of the fish community with changes in river gradient and physiographic areas (e.g., Piedmont Fall Line zone assemblage versus Coastal Plain assemblage) (Progress Energy 2003). Additionally, by grouping species into guilds, the number of required HSC curves and resulting model output could be reduced to a manageable level for data management and interpretation. In a workshop session from June 9 to 10, 2004, the IFSG finalized development of habitat guilds and the species life stage HSC to represent each guild. Guild associations are presented in Table 5-1. The four habitat-based guilds agreed upon by the IFSG are as follows: 1. Shallow slow guild (<2 ft deep, <1 ft/sec velocity) represented by 5 HSC; 2. Shallow fast guild (<2 ft deep, >1 ft/sec velocity) represented by 3 HSC; 3. Deep slow guild (>2 ft deep, <1 ft/sec velocity) represented by 3 HSC; and 4. Deep fast guild (>2 ft deep, >1 ft/sec velocity) represented by 3 HSC. Next, the IFSG selected individual target species/life stages from the list based on their management importance. Target species consist primarily of either diadromous fish species, RTE fish and mussel species, or fish species of recreational importance. Individual target species and life stages that were agreed upon by the IFSG and modified through consultation are listed in Table 5-2. Pertinent comments in the selection process are also included. Table 5-2 Target Species and Life Stages for Individual HSC Analyses in the Pee Dee

River Instream Flow Study. Fish/Mussel Species Life Stage Comment

American shad Spawning Modified Stier and Crance (1985) curves based on Swift River Project

Blueback herring Spawning/Incubation Juvenile

Dropped from instream flow analysis; preferred habitat is lower coastal plan downstream of study area

Striped bass Spawning/Incubation Use Roanoke River HSC information which was also used on Oconee River

Juvenile Represented by deep-slow and deep-fast guilds Adult Represented by deep-slow and deep-fast guilds American eel Elver/Upstream

Migrant Habitat generalist; dropped from instream flow analysis

Shortnose sturgeon Spawning/Incubation Brownell (2001) modification of Crance (1986) combined with Atlantic sturgeon

Atlantic sturgeon Spawning/Incubation Brownell (2001) combined with shortnose sturgeon Robust redhorse Spawning/Incubation Freeman and Freeman (2001); Leonard and Dilts (2003b) Carolina redhorse (proposed surrogate species: golden redhorse)

Spawning/Incubation Juvenile Adult

Personal communication with Dr. Wayne Starnes (North Carolina State Museum of Natural Science) and Dr. Bob Jenkins (Roanoke College, Virginia). Use golden redhorse as surrogate for adult and juvenile, spawning - shallow fast, moderate velocity generic curve


5-4

Fish/Mussel Species Life Stage Comment White bass Spawning/Incubation

Juvenile Adult

Included as guild representatives; spawning - deep fast and juvenile - deep slow with cover; adult - reservoir inhabitants

Mussels All No specific HSC available, will use general wetted perimeter area as measure of habitat availability

Macrobenthic invertebrates All Use Dr. Jim Gore’s generalized large river macrobenthic invertebrate community diversity HSC

5.2 Habitat Suitability Criteria Habitat suitability criteria or indices define the range of conditions that a particular species life stage will inhabit. Variables typically defined with HSC curves include depth, velocity, instream cover, and bottom substrate. HSC values range from 0 to 1.0, indicating habitat conditions that are unsuitable to optimal, respectively, for a species/life stage. The HSC provide the biological criteria input into the hydraulic model that converts physical habitat simulation data into WUA for evaluation of various flow scenarios on the particular species and life stage(s) of interest. The IFSG met from June 9 to 10, 2004, in a workshop session to develop or modify the HSC for target (stand alone) species/life stages and guilds. The results of this session are presented in Table 5-3 and Appendix B-1 with supporting documentation. The HSC for each species/life stage representing either stand alone target species or representing a guild are provided in Appendix B-10. Additional HSC documentation is included in Appendix B. 5.3 Species and Life Stage Periodicity The period of year when a species or life stage is present in the study area is an important component of the habitat duration model. The periodicity of each of the target species and life stages (Table 5-3) was determined in consultation with the IFSG and relied primarily on literature resources and professional input from regional biologists.

Affected Species, Periodicity, and Habitat Suitability Criteria

5-5

Table 5-3 Periodicity of Pee Dee River PHABSIM Target Species/Life Stages and Guilds (Revised March 10, 2005 at the Instream Flow Subgroup Meeting).

TargetLifestage1

American shad2 Sshortnose sturgeon2 S/IAtlantic sturgeon2 S/I * * * *

robust redhorse2 SCarolina redhorse2 J/Astriped bass2 Sstriped bass2,3 I/L

For species/life stages representing guilds, periodicity set for year round - each guild represents many species/life stages that use that habitat.

redbreast sunfish S silver redhorse Y silver redhorse Y shallow slow generic generic bluehead chub Y

margined madtom A shallow fast generic generic fantail darter A

deep slow generic generic deep slow generic generic redbreast sunfish A

silver redhorse A white bass S shorthead redhorse A

benthic macro - E,P,T N.A.

Jul Aug Sep OctJan Feb Mar Apr May Jun Nov Dec

Deep Slow

Deep Fast

Others

Resident Fish

Diadromous Fish

Guild Representatives Shallow Slow

Shallow Fast

Target Species

1 Life stages: S-spawning; I-incubation; L-larval; F-fry; Y-young of year; J-juvenile; A-adult. 2 Jenkins, R.E. and N.M. Burkhead. 1993. Freshwater Fishes of Virginia. American Fisheries Society, Bethesda, Maryland. 3 This time period was estimated to begin two-thirds of the way through the spawning period and lasting 60 days post spawn. *A ripe flowing male collected in fall 2003 suggests a possible fall spawning population.

Section 5

6-1

Section 6 - PHABSIM Study Design 6.1 Introduction An instream flow study involves numerous components. One of the primary components is the habitat simulation model or PHABSIM briefly described in Section 2 of this report. Nearly all of the consultation, study design, and field effort in the Pee Dee River Instream Flow Study were in support of PHABSIM. However, in tandem with the PHABSIM, the data collected also supported other analyses including the habitat duration analysis, peaking analysis, and wetted perimeter analyses. As briefly described in Section 2, field studies in PHABSIM are not conducted in a continuous manner over the entire reach of river affected, but rather within specified sections of river and at numerous discrete and representative locations. In order of largest to smallest geographic extent, these include the study area, study reach, subreach, and transect. In the current study, these discrete and representative locations were selected through consultation with the IFSG. Input to this process included information on project configuration and operations, hydrologic records and analyses, basin and channel characteristics, physical habitat surveys and mapping, water quality, site visits, and professional judgment and interpretation. The following describes the study area, study reach, subreach, and transects selected for the Pee Dee River Instream Flow Study. In this study, RMs were used to identify reach and subreach boundaries and study feature locations. Throughout this collaborative process, tables evolved and exact RM locations of features changed from the initial IFIM Study Plan. During the course of subreach designation, transect selection and data collection, various iterations of RMs were stated and altered. The range of change was small and was measurable in tenths of a mile. All RMs stated in this document are the final RMs used. A complete RMs table can be found in Appendix C-3. 6.1.1 Study Area and Study Reach Study Area The section of river affected by the Tillery and Blewett Falls developments constitutes the “Study Area.” The upper boundary of an instream flow study in a FERC hydro relicensing proceeding is usually the upstream point of regulated flow control associated with the project; either a hydroelectric dam with powerhouse or point of water diversion. The designation of the downstream boundary is usually based on a combination of professional judgments by the involved stakeholders using any available empirical flow and biological data. The downstream boundary is usually placed at the point where the hydraulic effects of power plant flow regulation are minimal or biologically negligible. The IFSG established the Pee Dee River Instream Flow Study Area Boundaries for the two developments as: (1) starting from the farthest downstream point at the U.S. Highway 76/S.C. Highway 301 Bridge at RM 100.2 located near Florence, South Carolina to the base of the Blewett Falls Dam at RM 188.2; and (2) from the headwaters of Blewett Falls Lake at RM 196.2 to the farthest upstream end at the base of the Tillery Dam at RM 218.0. Only the mainstem Pee Dee River and mainstem side channels were included in the instream flow Study Area; both project reservoirs

Section 6 PHABSIM Study Design

6-2

were excluded. This instream flow Study Area, as defined, also excludes any flow/habitat studies in tributaries entering these sections of river. Study Reach For the purposes of this study, a reach is defined as a section of river having similar physiographic and hydrologic characteristics throughout its length. The primary rationale used by the IFSG to segment study reaches were the two hydroelectric developments and the physiographic/hydrologic differences between the Coastal Plain and Piedmont Provinces. Additionally, other attributes considered were biological resources and water quality. Therefore, the IFSG divided the 117.8-mile Study Area into three reaches as described in Appendix A-2 - Pee Dee River Instream Flow Study Plan and shown in Table 6-1. Table 6-1 Final Name, Description, and RM Location of the Study Area and Study

Reaches Defined by the Instream Flow Subgroup.

Study Area and Reach Description From RM To RM Length

(mi)

% of Study Area

Study Area Florence at U.S. Highway 76/S.C. Highway 301 to Tillery Dam

100.2 218.0 117.8 100

While the total Study Area was 117.8 RM in length, Blewett Falls Lake/Grassy Islands Shoals was not included in the calculations shown below. The total riverine study area was 109.8 miles long.

Reach 1 - Coastal Plain Florence at U.S. Highway 76/S.C. Highway 301 to just above U.S. Highway 1 at Cheraw

100.2 164.8 64.6 58.8

Reach 2 - Lower Piedmont Cheraw/U.S. Highway 1 to Blewett Falls Dam

164.8 188.2 23.4 21.3

Reach 3 - Upper Piedmont Upstream end of Grassy Islands/Blewett Falls Lake to Tillery Dam

196.2 218.0 21.8 19.6

6.1.2 Study Subreaches PHABSIM requires that the study reaches be further segmented into homogenous sections of river that have fairly uniform slope, channel morphology, sinuosity, and flow regime. In this study, these are termed “subreaches.” Generally, subreach boundaries are placed at major river confluences, abrupt changes in slope (such as the Fall Line between the Piedmont and Coastal Plain Provinces), substantial changes in sediment supply or water quality, and at flow impoundment and diversion structures. The IFSG segmented the three study reaches into eight subreaches2. Stratification of reaches into subreaches permits a more accurate assessment of flow characteristics and the resultant effects on

2 A nested numbering system for reaches and subreaches was used for the Pee Dee River instream flow study. In

nested numbering, subreaches are numbered beginning with the number one at the bottom of each reach. Reaches, subreaches, and transects are all numbered in an upstream direction. For example, R1/SR2 corresponds to Subreach 2 of Reach 1.


6-3

aquatic habitat. As a general rule, a segment should contain more than 10 percent of the total length of river under study, unless the segment boundaries are clearly defined by changes in flow regime or the segment contains a “critical reach” (Bovee 1982, 1998). Subreaches were originally defined by the IFSG based on review of topographic maps, aerial video, and group members’ personal knowledge of the Pee Dee River. These demarcations were further analyzed by DTA using channel sinuosity, slope, width, water quality, and standard guidelines (Bovee 1982, 1998) as a basis for segmentation (Table 6-2). Figure 6-1 presents the longitudinal profile of the Pee Dee River study area. While many of the boundaries were appropriately placed initially, some were moved or eliminated by the IFSG after further evaluation. A brief summary of the final reaches and subreaches defined by the IFSG is described in Table 6-3. Figures 6-2 through 6-9 show subreach transect locations. For more detail on subreach demarcation, refer to Appendix A-2 - Pee Dee River Instream Flow Study Plan. 6.1.3 Study Transects A transect is a reference line established at a specific location across the river channel (from river bank to river bank) that is generally perpendicular to the direction of flow where instream flow variables are measured or surveyed. It is usually marked with a steel headpin on one bank and a steel tailpin on the opposite bank. In this study, the head pin and tailpin are on the left and right banks (looking upstream), respectively. All measurements along the transect are referenced by their distance from the headpin, typically using a measuring tape or tagline. Collectively, transects are selected to best represent the mixture of channel and habitat types present in the subreach. A total of 74 transects were selected within the three reaches in the Pee Dee River Study Area. Between 3 and 12 transects were selected in each subreach, depending on the complexity and diversity of habitat types present in the subreach (Tables 6-4 through 6-11). The location and number of transects required in each subreach were based on results of habitat mapping, IFSG site visits, and professional judgment of IFSG members. For information on habitat mapping, refer to Section 7 of this report. For a detailed description of the transect selection process, refer to Appendix A-2. Figures 6-2 through 6-9 show transect locations. For detailed information of all PHABSIM transect locations, RMs, photos and cross sections, and represented habitats, refer to Appendix C-1.


6-4

Table 6-2 Pee Dee River Subreach Sinuosity, Channel Width, and Slope. Channel Width Reach Subreach Sinuosity Index

Avg Max Min Slope (ft/mi)

1 1.24 288 321 239 0.84 2 1.60 320 434 236 0.82 3 1.34 318 537 183 0.48 1

Average 1.39 1 1.20 422 588 335 1.05 2 1.08 689 917 516 1.27 3 1.17 837 1317 374 3.15 2

Average 1.15 1 1.15 580 720 473 0.34 2 1.05 461 556 264 1.25 3 1.26 529 708 450 2.33 3

Ave age r 1. 5 1

0

50

100

150

200

250

80 100 120 140 160 180 200 220 240

River Mile

Elev

atio

n (ft

) Abo

ve M

SL

R1/SR10.84 ft/mi

R1/SR20.82 ft/mi

R1/SR30.48 ft/mi

Blewett Falls Dam

R2/SR11.05 ft/mi

R2/SR21.27 ft/mi

R2/SR33.15 ft/mi

R3/SR10.34 ft/mi

R3/SR21.25 ft/mi

R3/SR32.33 ft/mi

Tillery Dam

Figure 6-1 Longitudinal Profile of the Pee Dee River Instream Flow Study Area.


6-5

Table 6-3 Final Reach and Subreach Description Defined by the Instream Flow Subgroup.

Reach/ Subreach Name Description From RM To RM Length

(mi)

% of Study Area

Reach 1 - Coastal Plain Florence at U.S. Highway 76/S.C. Highway 301 to Highway 1 at Cheraw

100.2 164.8 64.6 58.8

Subreach 1 US Highway 76/S.C. to Cashua Ferry/S.C. Highway 34

100.2 116.1 15.9 14.5

Subreach 2 Cashua Ferry/S.C. Highway 34 to Cheraw/U.S. Highway 1

116.1 164.8 48.7 44.4

Reach 2 - Lower Piedmont Cheraw/U.S. Highway 1 to Blewett Falls Dam

164.8 188.2 23.4 21.3

Subreach 1 U.S. Highway 1 to N.C./S.C. state line 164.8 173.0 8.2 7.5 Subreach 2 N.C./S.C. state line to Hwy 74 173.0 184.6 11.6 10.6 Subreach 3 Hwy 74 to Blewett Falls Dam 184.6 188.2 3.6 3.3

Reach 3 - Upper Piedmont Upstream end of Grassy Islands/Blewett Falls Lake to Tillery Dam

196.2 218.0 21.8 19.9

Subreach 1 Upstream end of Grassy Islands/Blewett Falls Lake to Brown Creek confluence

196.2 206.5 10.3 9.4

Subreach 2 Brown Creek confluence to Rocky River confluence

206.5 212.6 6.1 5.6

Subreach 3 Rocky River confluence to Tillery Dam

212.6 218.0 5.4 4.9


6-6

Reach 1-Subreach 1 (Table 6-4; Figure 6-2) is a total of 15.9 miles long. Channel form and hydraulics in SR1 are not complex. The lower end of this reach is comprised mostly of slow pools and glides, both open and heavily vegetated banks, and large woody debris. In addition to the habitat types found in the lower end of the reach, the upper end also includes a meandering section containing a few point bars and cut banks. The PHABSIM study site section encompasses the range of hydraulics and channel types found in the subreach. There are no potential navigation impediments identified in this subreach. Boat access is at S.C. Highway 34 (Cashua Ferry Landing). Table 6-4 Pee Dee River Final PHABSIM Transect Description Reach 1-Subreach 1.

Transect Description RM T1 Transect location is on the downstream end of a shallow bend. Large woody debris

and sand dominate the outside shoreline. This habitat type is prevalent throughout the reach.

108.90

T2 Shallow inside of bend with depths increasing and woody debris collecting on inside and outside

109.00

T3 Transect location is at the upstream end of the bend. Depths appear to increase and velocities decrease from inside of the bend to outside. Mid-channel woody debris is apparent in the corresponding photograph.

109.10

T4 Transect location is at the downstream edge of a sharp bend. A large amount of large woody debris and higher velocities on the outside of the bend is apparent in the corresponding photograph.

109.30

T5 Transect location is at the apex of the sharp bend. High amounts of large woody debris and greater depths exist on the outside while a sandbar creating backwater conditions dominates the inside shoreline.

109.40

T6 Transect location is at the upstream end of sharp bend. Depths increase toward the outside of the bend creating a sandbar on the inner shoreline.

109.50

T7 Transect location is on a sharp bend where a sandbar and large backwater has been created. The size and complexity of this backwater area is unusual in this reach.

109.85

T8 Transect crosses a backwater and a sand bar vegetated with a dense stand of black willow. The bar and associated vegetation is only inundated at higher flows. Only a stage discharge and bed profile will be established at this transect.

109.90

T9 Transect location is on the downstream end of a straight section. The channel in this area appears to be laterally uniform in width and depth. This habitat type is common throughout the reach.

110.85

T10 Transect location is on a shallow bend. Sandbar located on the inside of the bend and a small amount of large woody debris on the outside.

111.00

T11 Transect location is on backwater, a common habitat type in this reach. 111.35


6-7

Figure 6-2 Reach 1-Subreach 1 Final Transect Locations.


6-8

Reach 1-Subreach 2 (Table 6-5; Figure 6-3) is 48.7 miles long with both straight and meandering channel forms. While the channel and habitat types are not complex, there is a diversity of channel forms due to extensive meandering. The meanders form cut banks, backwaters, and point bars and mid-channel bars composed of gravel and sand. RTE species including the robust redhorse, shortnose sturgeon, and Atlantic sturgeon have been captured or observed at several locations in Subreach 2. There are two study sites in Subreach 2; the lower site (1A) includes a known spawning site for shortnose sturgeon and an area of boating navigation restriction during extremely low-flow periods (Byrds Island shoal), and the upper site (1B) includes both straight and meandering channel forms. The unique feature in this site is the large mid-channel sand and gravel bar at RM 132.5, where juvenile robust redhorse and adult Atlantic sturgeon have been captured. There are two potential navigation impediments identified in this study site. Table 6-5 Pee Dee River Final PHABSIM Transect Description Reach 1-Subreach 2.

Transect Description RM T1 A shortnose sturgeon sighting occurred in the vicinity of T1. Transect location is at the

downstream end of a straight section. The sandbar on the right establishes a chute on the left side of the channel, creating high velocities.

116.10

T2 Transect location for T2 is on the downstream end of a sharp bend. A sandbar is located on the inside shoreline. Depth increases and woody debris collects along the outer edge of the bend.

131.00

T3 Transect location is at the apex of sharp bend. Large sandbar on inside of bend with most of the depth and large woody debris collected on the outer edge.

132.00

T4 Transect location is at the upper end of a sharp bend. Sandbar located on inside of bend and large amounts of large woody debris on the outside shoreline. Channel depth appears to be becoming more uniform.

132.20

T5 Transect location is at the downstream end of a straight section of river with an extensive mid-channel gravel bar complex. The backwater created on the right side of the corresponding photo is noted.

132.40

T6 The location of transect 6 is across the mid-channel gravel bar complex. Channel depth is much greater on the left. The split channel created is noted in the corresponding photo.

132.45

T7 General transect location is in a straight section of the channel just across the mid-channel gravel bar complex. The split channel and large woody debris on the left side of the corresponding photo are noted.

132.55

T8 Transect location is on the upstream end of a straight section. The channel in this area is laterally uniform in width and depth. This habitat type is common throughout the reach.

133.20

T9 Transect location is on a shallow bend. A large sandbar creates a backwater area on the inside shoreline while most of the depth is on the outer edge.

133.30

T10 Transect location is on a shallow bend. A small mid-channel gravel bar separates the shallow sandbar area on the left from the much deeper right side of the channel.

133.40


6-9

Figure 6-3 Reach 1-Subreach 2 Final Transect Locations.


6-10

Reach 2-Subreach 1 (Table 6-6; Figure 6-4) extends 8.2 miles from the South Carolina state line to U.S. Highway 1/S.C. Route 9 near the town of Cheraw. Approved transect locations range from RM 170.25 to 165.70. The 12 transects were selected to represent the primary habitat types within SR1 in addition to a few unique habitat types (e.g., riffles). Transects were approved by the IFSG during a field visit on August 3, 2004. Table 6-6 Pee Dee River Final PHABSIM Transect Description Reach 2-Subreach 1.

Transect Description RM T1 Main Channel Deep Glide. Sand/rubble bottom with woody debris on left bank. Width =

360 ft; Depth = 9 ft. 165.70

T2 Side Channel Sand Glide. Woody debris. Bottom of Westfield Creek side channel. Width = 75 ft; Depth = 2-3 ft. No backwater effect at high flows.

165.80

T3 Main Channel Gravel/Boulder Run (step). Captures velocity shadows and boulder substrate.

167.10

T4 Main Channel Deep Run. Large boulders/cobble. Large woody debris. Backwater on left bank. Width = 350 ft; Depth = 3-5 ft.

168.10

T5 Main Channel Glide. Gravel/cobble. Width = 250 ft. 168.35 T6 Side Channel Shallow Glide. Gravel/sand substrate. Width = 65 ft. 168.23 T7 Side Channel Run. Top of Westfield Creek Side Channel. 168.30 T8 Side Channel Shallow Glide. Small gravel bar on right bank. Woody debris on left bank.

Width = 170 ft; Depth = 1-2 ft. 168.35

T9 Main Channel Wide Run (riffle). Cobble/gravel substrate. Top of Great Island. Width = 710 ft; Depth = 1.5-3.0 ft. Potential spawning habitat.

168.50

T10 Main Channel Moderate Depth Glide. Cobble/gravel substrate. Width = 520 ft; Depth = 5-6 ft.

169.60

T11 Main Channel Shoal. Boulder/cobble/gravel/sand. Width = 700 ft; Depth = 1 ft. 170.25 T12 Main Channel Shoal. Boulder/cobble/gravel/sand. Width = 700 ft; Depth = 1 ft. 170.25


6-11

Figure 6-4 Reach 2-Subreach 1 Approved Transect Locations.


6-12

Figure 6-4 (Continued)


6-13

Reach 2-Subreach 2 (Table 6-7; Figure 6-5) extends 11.6 miles from U.S. Highway 74 to the South Carolina state line. Approved transect locations are in the Jones Creek Shoal area extending from RM 177.20 to 178.15. Nine transects were selected to represent the primary habitat types within a complex island/shoal system, and one transect at RM 184.45 was selected to represent pool habitat. Transects were approved by the IFSG during a field visit on August 2, 2004. Table 6-7 Pee Dee River Final Transect Description and Location Reach 2-Subreach 2.

Transect Description RM T1 Main Channel Run 177.20 T2 Main Channel Shoal 177.40 T3 Main Channel Shoal 177.58 T4 Side Channel Gravel Glide 177.65 T5 Side Channel Glide 177.55 T6 Side Channel Boulder Run 177.48 T7 Side Channel Bedrock/Boulder Glide. Width = 88 ft. 177.50 T8 Side Channel Shallow Gravel Glide. Width = 64 ft; Depth = 2-3 ft. 177.50 T9 Main Channel Deep Glide. Width = 800 ft; Depth = 10 ft. Even profile.

Bedrock/rubble/sand substrate. Transect is 500 ft of upstream of ramp. 178.15

T10 Deep Pool. Width = 560 ft; Depth = >20 ft. Directly under power lines. 184.45


6-14



6-15

Reach 2-Subreach 3 (Table 6-8; Figure 6-6) extends 3.6 miles from the Blewett Falls Hydro Project to U.S. Highway 74. Approved transect locations range from RM 186.95 to 184.45. The nine transects were selected to represent the primary habitat types within Subreach 3. Transects were approved by the IFSG during a field visit on August 2, 2004. Table 6-8 Pee Dee River Final PHABSIM Transect Description Reach 2-Subreach 3.

Transect Description RM T1 Deep Pool. Width = 560 ft; Depth = >20 ft. Directly under power lines. 184.45 T2 Irregular Bedrock Shoal 185.05 T3 Irregular Bedrock Shoal. Includes patches of gravel/sand. 1/3 channel exposed bedrock

at low flow. Width = 875 ft; Depth = 6 ft. Over gas pipeline right-of-way. 185.15

T4 Glide. Bedrock with rubble and sand. Width = 700 ft; Depth = 9 ft. At Walls Landing. 186.20 T5 Bedrock/Boulder Run. Includes patches of sand/gravel. Width = 720 ft; Depth = 4-5 ft. 186.35 T6 Bedrock/Gravel Run. Good habitat diversity. Small amount of woody debris. Width =

160 ft; Depth = 2-4 ft. 186.70

T7 Gravel/Sand Glide with Backwater 186.85 T8 Pea Gravel/Sand Glide with woody debris on left bank. Width = 130 ft; Depth = 2 ft. 186.95 T9 Smooth Bedrock/Boulder Shoal. Main channel of simple island complex. Includes broad

gravel shoulder along left bank. Shallow on insider bend 4-6 ft deep on outside bend. Shallow water fish and mussel surveys here. High abundance of both. Width = 700 ft; Depth = 0-6 ft.

186.80



6-16

Reach 3-Subreach 1 (Table 6-9; Figure 6-7) extends 10.3 miles from the head of Grassy Islands at the head of Blewett Falls Lake to N.C. Highway 109. Approved transect locations are within two miles downstream of N.C. Highway 109 and a public boat launch. The three transects were selected to represent the primary habitat types within Subreach 1. Transects were approved by the IFSG during a field visit on April 19, 2004. Table 6-9 Pee Dee River Final Transect Description and Location Reach 3-Subreach 1.

Transect Description RM T1 Moderate Depth Glide with Sand and Rubble 203.20 T2 Deep Pool 203.70 T3 Shallow Glide with Sand and Rubble 204.35



6-17

Reach 3-Subreach 2 (Table 6-10; Figure 6-8) extends 6.1 miles from the Brown Creek confluence to the Rocky River confluence. Approved transect locations are within a two-mile reach from just above Brown Creek to just above Leak Island. The 12 transects were selected to represent the primary habitat types within Subreach 2. Table 6-10 Pee Dee River Final Transect Description and Location Reach 3-Subreach 2.

Transect Description RM T1 Lateral step 207.30 T2 Moderate Depth Glide 207.80 T3 Cobble/Gravel Glide. Main channel Buzzard Island 209.70

T4 Left Channel Run in main channel at top of Buzzard Island and glide in side channel. 209.80 T4 Right Channel Split Channel Glide (continuation of above) 209.80

T5 Main Channel Pool 210.15 T6 Main Channel Run 210.90 T7 Split Channel Glide or Run 209.40 T8 Run (Side Channel of Buzzard Island above confluence) 209.75 T9 Split Channel Glide (main Leak Island side channel) 209.00 T10 Gravel/Cobble Riffle of Leak Island side channel 210.00 T11 Run of Leak Island side channel 210.00 T12 Main channel moderate depth glide (also used for total discharge for split flow

calculation) 211.50


6-18



6-19

Reach 3-Subreach 3 (Table 6-11; Figure 6-9) extends 5.4 miles from the Rocky River confluence upstream to Tillery Dam. Approved transect locations are within an approximate two-mile reach and represent the mixture of habitat types within Subreach 3. Table 6-11 Pee Dee River Final Transect Description and Location Reach 3-Subreach 3.

Transect Description RM T1 Glide with randomly scattered bedrock 214.85 T2 Glide with lateral bedrock and gravel bar on left bank 215.70 T3 Shallow glide with gravel bar along left shoreline and mid channel cobble

and gravel 216.00

T4 Glide with left bank gravel bar and boulder bedrock in mid channel 216.30 Navigation Transect Transect located on shoal and on an old diversion dam 216.50

T5 Run with gravel bar on left bank and scattered bedrock/cobble 216.60 T6 Run with scattered bedrock/cobble 216.80 T7 Tail of shoal with lateral bedrock and scattered cobble 217.00 T8 Head of Shoal 217.30


7-1

Section 7 - Field Data Collection 7.1 Introduction Physical habitat and hydraulic parameters were measured using a combination of standard techniques of the USFWS IFIM methodology (Trihey and Wegner 1981; Bovee 1982; Bovee et al. 1998), the USGS (Rantz 1982), and techniques established in consultation with the IFSG. PHABSIM data collection and modeling procedures varied between subreaches, depending on hydraulic and channel complexity. The two-velocity data set method was used for certain transects within subreaches with the least complex channel geometry and hydraulics, or where safety concerns precluded high-flow data collection. A three-velocity data set method was applied in the subreaches with the most complex channel geometry and hydraulics. Differences between the methods and an explanation of when each was used are described below. River flows during calibration measurements were regulated by Progress Energy and coordinated with the upstream APGI-owned Falls Development during the study to achieve specific target flow levels within each study reach. Flows were held as steady as possible during flow measurements. Staff gages were installed and monitored or continuous-recording water level instruments were installed in some cases (Reach 3), to provide a record of stage/flow stability. 7.2 Surveying and Controls Standard differential surveying techniques were used at each transect. A total station instrument or a survey auto-level was used with temporary benchmarks to measure headpin and tailpin elevations, water surface elevations (WSE), hydraulic controls, and above-water bed and bank elevations. Vertical measurements were accurate to the nearest 0.02 ft. All elevations for the PHABSIM were arbitrary. Elevations were not referenced to a geodetic datum. 7.3 Channel Structure Cross Sectional Profiles - Channel cross-sectional profiles between each headpin and tailpin were obtained at all transects. Bed elevations above the water surface were determined by using standard survey techniques. Bank profiles were surveyed beyond the pins to evaluate above-bankfull flow ranges. Bed elevations below the water surface were obtained by subtracting the measured depths taken during the velocity calibration from the WSE for that particular transect. Hydraulic Controls - Elevation of hydraulic controls within the study site were obtained by standard survey techniques using the channel survey and/or GPS instruments. In some cases where the controls were too deep to wade, the acoustic Doppler current profiler (ADCP) was utilized to first locate the hydraulic control. 7.4 Hydraulics The PHABSIM hydraulic model requires at least three water surface elevation/discharge (WSE/Q) pairs for the stage/discharge regression equation. Bovee et al. (1998) advises that the hydraulic calibration data should include at least three WSE/Q data pairs and one set of calibration velocities.

Section 7 Field Data Collection

7-2

High and low calibration discharges should differ by at least one-half (preferably a full) order of magnitude. In order to simulate side channel habitat accurately, it is necessary to measure the distribution of total discharge among the side channels at each hydraulic calibration. Calibration discharges required for model development are often constrained by low-flow limits of the turbines. At the low calibration flow, turbine damaging cavitation and/or vibrations can occur. Thus these flows were delivered under closely monitored conditions for very short periods of time. Progress Energy does not normally operate units at this low level, and provision of these flows for study purposes over a short period of time should not be construed as an indication of the ability of Progress Energy to deliver these low flows for longer periods of time. WSE/Q - WSE/Q measurements were obtained at no fewer than three discharges. Additional WSE/Q measurements were collected at leakage flows at specific reaches determined by the IFSG. Water surface elevations at each transect were obtained using standard survey techniques. The number and placement of WSE points were dependent on water depth. In simple channels where the water was too deep to stand anywhere but along the edge, two points were measured — one on each shoreline. Water surface elevations were measured on all shorelines in a split channel. Whenever possible, additional mid-channel measurements were taken; the number and placement of measurements were dictated by the variation in WSE across the transect. Discharge through the study site was measured using a combination of calibrated ADCP and manual velocity meters. At least three ADCP measurements with mean error of less than five percent were obtained for estimation of discharge. These discharges were then averaged to obtain one transect discharge. Only one discharge estimate is required per WSE/Q data set for the PHABSIM hydraulic model. Calibration Velocities - In addition to the WSE/Q calibration, two calibration velocity sets were collected at each transect in subreaches predominated by simple channel geometry and hydraulics (i.e., deep and shallow glides and pools in Reach 1). Three calibration velocity sets were collected in complex channels with complex hydraulics (i.e., split channels with boulder runs and shoals in Reaches 2 and 3). The final determination of the number of WSE and velocity calibration sets was made on a subreach-by-subreach basis after further field reconnaissance and consultation with the IFSG. When conditions were suitable and safe, depth and velocity distributions and discharge were measured from a boat using the ADCP. The ADCP uses acoustic pulses to measure water velocities and depths across the channel. According to an extensive evaluation conducted by the USGS (Morlock 1996), an ADCP can be used successfully for data collection under a variety of field conditions. The ADCP hydraulic measurements were made from a cataraft by moving the ADCP across the channel while it collected vertical-velocity profile and channel-depth data. The ADCP tracks the distance traveled from the point of origin so each depth and velocity measurement would be coordinated with a horizontal distance on the transect. Measurements were taken at close intervals (approximately 1 to 3 ft) across each transect and at multiple levels in the water column. The ADCP was connected by cable to a DC power source and to a laptop computer. The computer was used to program the instrument, monitor its operation, and collect and store the data.


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The ADCP (boat) course along transects less than 700 ft wide were maintained by closely following a tagline stretched from the left bank headpin to the right bank tailpin. Maximum deviation from the course line using this system was within 2 ft. At transects wider than 700 ft (maximum tagline length), the boat helmsman used a GPS-based real-time navigation software program viewed on a laptop computer to follow a straight-line course between the headpin and tailpin. Maximum deviation from the course line using this system was within 5 ft. Because the ADCP will not measure in depths less than approximately 2.0 ft, shallow measurements near shore and at other locations were taken manually using a calibrated, digital Swoffer® brand, propeller-type velocity meter mounted on a standard top-set USGS wading rod. Manually measured velocities were taken at six-tenths of the depth when depths were less than 2.5 ft, at two-tenths and eight-tenths of the depth when depths equaled or exceeded 2.5 ft, and when the expected velocity profile was altered by an obstruction immediately upstream. These rules for placement of verticals (measured velocities) along each transect were closely followed. If there was uncertainty as to whether a vertical was warranted, the vertical was usually placed at that point. In addition to stationing, notes were taken regarding the top set relative to upstream obstructions and substrate that affected the velocity column. Because each calibration flow was modeled separately, it was not necessary to position the top set in the exact position it was placed in a previous calibration flow measurement. Temporary staff gage levels and the time of day were recorded at the beginning and end of each transect measurement to note potential changes in stage. In-situ continuous recording level-loggers were installed in Reach 3 to monitor changes in stage during the calibration measurements. Target and measured discharges are presented in Appendix D-4. 7.5 Substrate and Cover Substrate and cover were measured visually and/or by tactile inspection at wadeable depths. Substrates in deeper water or with poor to no visibility were measured by “feeling” substrate coarseness using a long metal rod. Occasionally, it was necessary to assume a substrate type (i.e., only where substrate was very fine on the banks and exposed beds of very low gradient, pool habitats) when direct visual or tactile assessment would not work. Classification was performed in accordance with the NCDWR methods and was coded using the codes shown below in Tables 7-1 and 7-2. Note that proximal cover is a cover object not at a vertical, but within 4.0 ft in any direction. Table 7-1 NCDWR Substrate Size Classification and Codes. Modified for the Pee Dee

River by the IFSG. Code Abbreviation Description Inches

0 ORG Organic Detritus N/A 1 SI Silt, Clay <0.1 2 SA Sand <0.1 3 SGR Small Gravel 0.1 0.5 4 MGR Medium Gravel 0.5 1.5 5 LGR Large Gravel 1.5 3.0 6 SCOB Small Cobble 3.0 6.0 7 LCOB Large Cobble 6.0 12.0 8 SBOL Small Boulder 12.0 36.0 9 LBOL Large Boulder >36.0

10 SBR Smooth Bedrock N/A 11 IBR Irregular Bedrock N/A


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Table 7-2 NCDWR Cover Type Classification and Codes. Modified for the Pee Dee

River by the IFSG. Overhead Cover Proximal Cover

Code Abbreviation Description

Abbreviation Code 0.0 NC No Cover N/A 0.1 UCB Undercut Bank PUCB 0.14 0.2 OHV Overhanging Vegetation Touching Water POHV 0.24 0.3 ROOT Root Wad (greatest width 1.5 ft) PROOT 0.34 0.5 SNAG Snags and Stream Wood PSNAG 0.54 0.6 WEED Submerged Aquatic Vegetation PWEED 0.64 0.7 DEB Fine Organic Substrate PDEB 0.74 0.8 TV Terrestrial Grass and Bushes N/A 0.9 ISC Instream Cover PISC 0.94

7.6 Habitat Mapping In the PHABSIM, habitat typing is used to characterize and categorize the types of habitats (e.g., pools, runs, and riffles) in a river (Table 7-3). Habitat mapping quantifies the amount and distribution of each habitat type. Results of habitat mapping are used in PHABSIM to select and weight each transect where hydraulic data are collected in proportion to the occurrence of that habitat type in the study reach. Table 7-3 Pee Dee River Meso-Habitat Descriptions.

Habitat Name Description

Shoal Shoals are relatively shallow, submerged ridges that occur with a consistent frequency down the longitudinal profile of the river. Shoals act as downstream controls to pools and glides and create the hydraulic conditions necessary to form runs immediately downstream. Substrate composition in shoals is typically bedrock, boulders, and coarse substrates. The “strength” of each hydraulic control dictates the magnitude to which it influences the upstream habitat types. Each shoal will create a unique situation upstream in which pools, glides or both may be identified.

Run Immediately downstream of the shoal, there is typically a transition area prior to the water entering the next pool or glide. This unit consists of relatively fast moving, turbulent water and a gradually descending bed profile. When mapping habitat in higher discharges (deeper flow), these areas can be visually identified by an upwelling of water just on the downstream edge of the shoal. This “roiling” effect is created by the sudden drop in water off of the shoal due to the lack of any backwater effect. Substrate composition varies from fine sediments to cobble and boulders. As the water begins to collect and back up further downstream, velocities slow, depths increase, and the transition into a glide or pool occurs.

Glide Depending on the strength of the shoal and the bed profile directly upstream of the control, a glide or a pool will be created. A glide is generally defined by slower velocities and a relatively uniform bed profile, but a rough bed profile is not uncommon. Glides will either progress into a more concave bed profile just upstream of the shoal (creating a pool), or maintain their uniform hydraulic and bed features until direct contact with the shoal. Substrates can be large or small but, except at very high flows, do not create turbulence. Due to the slower velocities and increased depths, finer substrates will typically begin to settle in glides.

Pool If the bed profile upstream of the shoal is more concave or possesses significant undulations, a pool will be formed. Pools are visually represented by the slowest velocities of the four main habitat types and the most extreme depths. Steep banks and narrow channels relative to the rest of the reach can often be associated with pools. The stronger or more defined the downstream control (shoal), the


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Habitat Name Description

more defined the pool. Substrate composition in pools generally consists of a layer (thick or thin) of finer substrates over boulder or bedrock.

Lateral Step Lateral steps in the Pee Dee River are created by a rapid rise and fall in the bed profile. Typically, they will not act as a strong downstream control and will look more like a small outcrop extending laterally across a lengthy singular habitat unit. At lower flows, these steps may be represented by a small cascade as the water falls over the downstream edge of the step. At higher flows, these steps will most likely be submerged and the hydrology at these locations may be somewhat disturbed and expressed by some “boiling” of the flow. In the Pee Dee River, many of the steps are believed to be the remnants of prehistoric Native American fishing weirs. The labyrinth-shaped weirs often stretch across the entire channel and are typically built on natural shoals. The substrate composition is typically boulder and bedrock.

Habitat typing and mapping can be accomplished on foot, by boat, by aerial photography/video, or a combination of all three methods. Because of the length of the study area (over 100 RMs), difficult access in many locations, and the width and depth of the Pee Dee River (in excess of 1,000 linear ft in some areas), typing and mapping by foot or boat alone was not practical. Therefore, Progress Energy mapped habitat using aerial videography techniques in combination with ground-truthing by boat in those reaches where habitat types were discernible by aerial video. In reaches where habitat types are more complex and not clearly discernible by video, habitat was mapped primarily by boat with the backup use of the aerial videography. Subsequent field visits for PHABSIM transect data collection also yielded habitat information that was used to derive habitat frequencies. The various information sources and their sequence are described below. ■ Aerial Videography – The study area was videotaped from helicopter on November 2 and 3,

2003, under base flow conditions (i.e., no power plant releases) and clear, sunny weather conditions. The video was taken in an upstream direction at a height of about 250 to 350 ft above the channel, at an average ground speed of 35 to 45 miles per hour. Flow conditions at the time of the videography ranged from approximately 75 to 3,000 cfs depending on distance from the power plants and amount of tributary inflow. Using the aerial videography, mesohabitat types were identified (Table 7-3) and frequencies were mapped and sampled by freezing the video at 10-second intervals and then typing the habitat crossed by a line drawn horizontally across the center of the monitor screen. This is essentially a systematic, but random, sampling because of the variation in the helicopter’s speed, the changing altitude and attitude of the camera, and the irregular linear distribution of habitat types. The method generated a frequency for each channel type that is generally proportional to the cumulative length of all channel units of that type. At a 10-second interval and a speed of 40 miles per hour, channel types would be sampled at an average spacing of 590 ft. The results of the aerial videography were formatted for DVD play and are available for review.

■ Field Typing by Boat – Because of the complexity of Reaches 2 and 3, DTA and Progress Energy also mapped these reaches by boat in March 2004. All data were GPS referenced.

■ Habitat Mapping in GIS – The GPS-referenced boat survey field data were entered into Geographic Information System (GIS) software. Habitat lengths and frequencies were derived and transferred to field maps. Both the aerial video and GIS maps were used in the field by the IFSG to select reaches, subreaches, and transects. Habitat maps are included in Appendix D-6.


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■ PHABSIM – Transect data. In all, 74 transects in three reaches (eight subreaches) were measured. Collected data included cross-sectional profile, velocity, depth, substrate, and cover.

Table 7-4 shows the methods employed to derive habitat frequencies in each reach, including information sources and methods utilized by reach and subreach. Table 7-4 Pee Dee River Habitat Mapping Methods and Information Sources.

Reach/Subreach Name Information Sources Coastal Plain – Reach 1:

Subreach 1 Aerial video mapping with PHABSIM transect ground-truthing Subreach 2 Aerial video mapping with PHABSIM transect ground-truthing

Lower Piedmont – Reach 2: Subreach 1 Boat survey mapping, aerial video mapping, and PHABSIM transect ground-truthing Subreach 2 Boat survey mapping, aerial video mapping, and PHABSIM transect ground-truthing Subreach 3 Boat survey mapping, aerial video mapping, and PHABSIM transect ground-truthing

Upper Piedmont – Reach 3: Subreach 1 Aerial video mapping with PHABSIM transect ground-truthing Subreach 2 Boat survey mapping, aerial video mapping, and PHABSIM transect ground-truthing Subreach 3 Boat survey mapping, aerial video mapping, and PHABSIM transect ground-truthing

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Section 8 - Habitat and Navigation Models 8.1 PHABSIM Model 8.1.1 Introduction As described in Sections 1 and 2, the primary means for quantifying habitat versus discharge in this study is the PHABSIM method developed by the USFWS. While the USFWS provides public domain programs and associated models, DTA uses a commercial version known as “RHABSIM” (Riverine Habitat Simulation), a commercial software program written by Thomas R. Payne and Associates of Arcata, California (Payne 1998). While PHABSIM and RHABSIM use a slightly different terminology for subroutines and modules, the terms from both are used interchangeably in this report. PHABSIM consists of three components: channel structure, hydraulic simulation, and aquatic HSC. Channel structure includes all fixed-channel features that generally do not change with discharge. These include channel cross-sectional geometry, substrate composition and distribution, and structural cover. Hydraulic variables are those that change with discharge, such as WSE, depth, velocities, wetted perimeter, and channel surface area. HSC are numeric representations of preferred depths, velocities, substrate, and cover for the various life stages of the aquatic species of interest (Bovee et al. 1998). The hydraulic modeling component predicts the values of hydraulic variables at discharges that were not measured. The aquatic HSC represent tolerances or preferences of aquatic organisms with respect to the hydraulic and structural characteristics of the stream. The primary preference variables are depth, velocity, and substrate/cover. 8.1.2 PHABSIM Programs Analysis and integration of physical stream measurements and habitat preference criteria require the use of PHABSIM computer programs. There are two main programs in the PHABSIM library: the hydraulic model (IFG-4) and the habitat model (HABTAT). The IFG-4 hydraulic simulation model predicts depth of flow and mean column velocities across the stream transect as a function of discharge. A log-log regression analysis is used to develop stage-discharge relationships at each transect and to predict velocity/discharge relationships at each habitat cell. Interpolation and extrapolation using regression equations allows modeling of flows between and beyond the measured discharges. The resulting simulated hydraulic information is then input to the HABTAT program. The HABTAT program integrates the simulated hydraulic information from IFG-4 with HSC (i.e., preference curves) and quantifies habitat availability over a range of flows for the specified target species and life stages. Habitat quantification is expressed as WUA, and is given in square feet of habitat per 1,000 linear ft of stream. 8.1.3 Hydraulic Model Procedures DTA used the “one-velocity set” modeling method for all Pee Dee River reaches. The one-velocity set method permits more flexibility in data collection and modeling than the traditional “three-

Section 8 Habitat and Navigation Models

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velocity set regression” method. While the two modeling methods are different, the same type and amount of data are collected in both methods. Data input files (decks) were compiled and calibrated using methods prescribed by the NCDWR. All of the input decks were initially processed using the Problem Report subroutine of the Field Data Entry Module of RHABSIM. This program looks for errors in data placement. Model extrapolation was determined in consultation with the IFSG. The IFSG agreed that the lower limit of extrapolation would be the current minimum flow or the “leakage” flow, whichever was greater. The upper limit of extrapolation would be 2.5 times the high-flow calibration measurement. The magnitude of flows modeled varied from reach to reach. Table 8-1 presents the extrapolation range for each subreach. Calibration Detail Tables, which summarize model changes and performance, are provided in Appendix D-1 of this report. Table 8-1 Calibration Flows and Model Extrapolations.

Extrapolation Calibration Flows Extrapolation Reach and Subreach Low End Leakage Low Middle High High End R1/SR1a 150 -- 1,191 -- 7,876 19,700 R1/SR1b 150 -- 1,191 -- 7,876 19,700 R1/SR2 150 -- 945 -- 7,872 19,700 R2/SR1 150 440 1,419 3,086 7,390 18,000 R2/SR2 150 432 1,310 3,110 6,600 16,335 R2/SR3 150 300 1,102 3,156 6,534 16,335 R3/SR1 70 -- 518 3,512 6,909 17,273 R3/SR2 70 -- 530 3,390 7,003 17,508 R3/SR3 70 189 870 3,076 6,924 17,310

The purpose of the model calibration is to accurately simulate the measured velocities and WSE at the observed flows while at the same time provide reasonable velocities and WSE at the range of simulated flows. One of the goals of the hydraulic simulation is to have the model accurately reflect measured velocities and depths at the calibration flows, while minimizing changes to the data. Calibration criteria used by DTA include: ■ Simulated velocities are within 0.2 ft/second (ft/sec) or 20 percent of the measured velocity (in

the one-velocity method, Manning’s N is the primary means of adjusting velocities); ■ Depths, based on WSE, are closely correlated to measured depths; ■ Mean error of the stage/discharge relationship is five percent or less; ■ Changes to velocities are kept to a minimum and the decks revised only when specific changes

improve model performance; and ■ MANSQ (channel conveyance) Beta range is 0.0 to 0.5. 8.1.4 Model Review and Approval Following initial calibration by DTA, all adjustments to the model were reviewed and approved by Mr. Thomas R. Payne of Thomas R. Payne and Associates, Arcata, California, an expert independent reviewer. The modeler made adjustments based on this review and then provided a calibration report of modeling details and the model run to Mr. Jim Mead of the NCDWR. Mr. Mead and


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Mr. Payne reviewed and discussed model performance and made additional changes as needed. This model review and approval approach was discussed and approved by the IFSG. 8.1.5 Hydraulic Model Performance All reaches were calibrated using the same procedures and criteria. Because model performance and calibration changes varied from subreach to subreach, each reach is discussed separately. Blewett Falls Development ■ Reach 1 - Subreach 1 - A three-point regression was used to model this subreach (high-flow

velocity set, middle- and low-flow WSE). A RHABSIM algorithm, “calculate best stage of zero flow,” was run to obtain an optimal stage of zero flow for all transects. This option was chosen because the bed controls did not control the WSE at flows from low flow and higher. Transect 8 was not modeled in RHABSIM; instead, the habitat was analyzed using a wetted perimeter method and is discussed in Section 8.4. All transects within the subreach were run using the log-log calibration method. The model ran within the range of performance criteria.

■ Reach 1 - Subreach 2 - A three-point regression was used to model this subreach (high-flow velocity set, middle- and low-flow WSE). A RHABSIM algorithm, “calculate best stage of zero flow,” was run to obtain an optimal stage of zero flow for all transects. This option was chosen because the bed controls did not control the WSE at flows from low flow and higher. All transects within the subreach were run using the log-log calibration method. Transect 1, however, was modeled separately due to complexities with channel location and geometry. The model ran within the range of performance criteria.

■ Reach 2 - Subreach 1 - A three-point regression was used to model this subreach (high- and low-flow velocity sets, middle-flow WSE). All transects within the subreach were run using the log-log calibration method. The model ran within the range of performance criteria.

■ Reach 2 - Subreach 2 - A three-point regression was used to model this subreach (high- and low-flow velocity sets, middle-flow WSE). All transects within the subreach were run using the log-log calibration method. It should be noted that Transect T10 is the same as Transect T1 from Subreach 3. The model ran within the range of performance criteria.

■ Reach 2 - Subreach 3 - A three-point regression was used to model this subreach (high- and low-flow velocity sets, middle-flow WSE). All transects within the subreach were run using the log-log calibration method. Manually entered “0.01” bank velocities were removed to improve transect stage/discharge relationship for several high-flow transects as well as the middle-flow Transect T4. A RHABSIM algorithm, “calculate best stage of zero flow,” was run to obtain an optimal stage of zero flow for all transects. The model ran within the range of performance criteria.

Tillery Development ■ Reach 3 - Subreach 1 - A three-point regression was used to model this subreach (high- and

low-flow velocity sets, middle-flow WSE). All transects within the subreach were run using the log-log calibration method. The model ran within the range of performance criteria.

■ Reach 3 - Subreach 2 - A three-point regression was used to model this subreach (high- and low-flow velocity sets, middle-flow WSE). All transects within the subreach were run using


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the log-log calibration method with the exception of Transects T9, T10, and T11. The depth calibration methodology was used to simulate velocities for these transects as the low flows were close to zero cfs. The model ran within the range of performance criteria.

■ Reach 3 - Subreach 3 - A three-point regression was used to model this subreach (high- and low-flow velocity sets, middle-flow WSE). Leakage WSE and calibration flows were measured in this subreach and separately modeled from the low-flow discharge down. Transects T1, T2, T3, and T5 within the subreach were run using the log-log calibration method. For Transects T4, T6, T7, and T8, the MANSQ methodology predicted calibration WSE more accurately than log-log. The model ran within the range of performance criteria.

8.1.6 Habitat Model Procedures Weighted Usable Area WUA is defined as “the sum of stream surface area within a subreach, weighted by multiplying area by habitat suitability variables (most often velocity, depth, and substrate or cover) which range from 0.0 to 1.0 each, normalized to square units (either feet or meters) per 1,000 linear units.” (Payne 2003 USGS website). It does not translate to actual area of suitable habitat but indicates the relative suitability of the available habitat. The HABTAT program calculates WUA through integration of the simulated hydraulic information from the IFG-4 hydraulic model with HSC (i.e., preference curves). WUA is quantified over a range of flows for the specified target species and life stages. Target Species and Habitat Suitability Criteria As previously discussed in Section 5, HSCs for both guilds and individual target species/life stages were applied. Habitat guild representative HSCs were used to simulate habitat for the native fish community of the Pee Dee River. HSCs for individual species were selected to represent high priority habitat for species of special management concern in each study reach. All guilds, species, and life stages included in Table 8-2 were modeled. Further documentation for the habitat guilds and target species is presented in Appendix B of this report. Table 8-2 Target Species, Guilds, and Life Stages Modeled for the Pee Dee River

PHABSIM. Target Species Target Life Stage1 Comments

Diadromous Fish American shad S Criteria from Swift Creek, Stier and Crance (1985). Shortnose sturgeon S/I Shortnose sturgeon and Atlantic sturgeon criteria were

combined into one curve. Substrate was modified to increase suitability of gravel.

Atlantic sturgeon S/I Shortnose sturgeon and Atlantic sturgeon criteria were combined into one curve. Substrate was modified to increase suitability of gravel. Modeled in Reaches 2 and 1 only below Blewett Falls Development.


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Target Species Target Life Stage1 Comments Striped bass S Striped bass I/L Resident Fish Robust redhorse S Golden redhorse J,A Use golden redhorse as surrogate for Carolina redhorse. Guild Representatives Native fish community (guilds). Shallow Slow Redbreast sunfish S Fine substrate without cover. Notchlip redhorse2 Run using two curves: One with woody debris cover and

one with aquatic vegetation cover. Notchlip redhorse Y Shallow slow generic Generic Coarse substrate. Bluehead chub Y No curves available for larval/fry; use YOY curve. Shallow Fast Margined madtom A Lower end of velocity range. Shallow fast generic Generic Middle of velocity range; no cover. Fantail darter A Higher end of velocity range; no cover. Deep Slow Deep slow generic With cover. Deep slow generic No cover. Redbreast sunfish A Deep Fast Notchlip redhorse A Adult has no cover. White bass S No cover; gravel/small cobble substrate. Shorthead redhorse A Coarse mixed substrate. Other Species of Interest Benthic macroinvertebrates

E,P,T Run using five curves: Macro Community HSC for large rivers; Ephemeroptera, Plecoptera, Trichoptera 1 (high preference for snag and debris); and Trichoptera 2 and 3 (low preference for snag and debris).

Mussels J and A Wetted perimeter analysis only. 1 Life stages: A = adult, I = incubation, J = juvenile, L = larval, S = spawning, Y = young of year, E,P,T =

Ephemeroptera, Plecoptera, Trichoptera. 2 Notchlip redhorse was formally called silver redhorse. 8.1.7 Transect Weighting Because different habitat types (e.g., pools, riffles, runs) do not occur in a subreach at the same frequency, a weighting factor must be applied to each habitat transect to calculate habitat availability in proportion to the occurrence in the subreach. For example, transects in a subreach with 25 percent pools, 50 percent riffles, and 25 percent runs would be weighted accordingly. The weight each transect receives was based on habitat mapping and professional judgment in consultation with the IFSG. Transect weighting can be simple or complex, depending on the stream or stream reach. On the Pee Dee River, some reaches were relatively simple to weight, while others that included multiple channels were much more complex to weight. For the purposes of this report, any bifurcation of flow is termed a split channel. A split channel section of stream includes simple splits (two


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concurrent channels) and compound splits (more than two concurrent channels). Transect weighting methods for the Pee Dee River are described below. Two different habitat classification methods were used: a channel-typing approach and a habitat-typing approach. The channel-typing approach was applied to simple channels (Reach 1) and the habitat-typing approach was applied to complex channels (Reaches 2 and 3). Channel-Typing Approach Reach 1 is a meandering stretch of river with high banks and off-channel habitats that are flooded at higher discharges. The reach has few split channels and is dominated by sandy and fine substrate, with high sinuosity and frequent sand bar formations with adjacent backwater habitat. This is a long reach but channel form has very minor changes from downstream to upstream. An analysis of channel geometry characteristics such as sinuosity, point bar form, bend length, and amplitude showed that some differences exist and change in an upstream direction. All the channel forms are present in all sections; it is the frequency of the feature and width of the channel that changes. Thus, the channel was fairly homogeneous and channel plan form and bank angle was the only indicator of habitat changes. The channel is very low gradient with primarily glide and pool habitat, but hydraulics around bends and riparian vegetation may affect the habitat. Aerial video, topographic maps, and PHABSIM transect results were used to generate a frequency for each habitat category that was proportional to the cumulative length of all habitat units of that type. The frequencies generated from this process determined the final “best representative” transect weighting for the reach. More information on this method can be found in Appendix D-2 - Transect Weighting Methods (Channel Typing). Final transect weighting is presented in Appendix D-3. Habitat-Typing Approach In the habitat-typing approach, individual habitat units were identified and their linear distances were either measured or their frequency was determined from the aerial video. For main channel reaches, such as subreaches 1 and 3 of Reach 3, habitat weighting was extracted directly from results of the habitat mapping boat surveys conducted by DTA. For each transect representing a habitat type, weighting factors were applied according to proportion of that particular habitat type length to the cumulative length of all channel units of that type in the subreach. For split channels (all of Reach 2 and Subreach 2 of Reach 3), a different approach was employed. This method resulted from discussion over the proper approach during a telephone conference call on May 27, 2005, including personnel with Progress Energy, DTA, the NCDWR, SCDNR, Entrix (APGI consultant), The Nature Conservancy of South Carolina, and the South Carolina Coastal Conservation League/American Rivers. This method identified three channel types: main channel, primary channel, and secondary channel. A main channel contains 100 percent of the flow; a primary channel contains the majority of the flow and the thalweg when there is a split in the channel; and a secondary channel contains the least flow and does not include the main thalweg in a split channel situation.


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The total length of a split channel complex was determined as the distance from the tip of the uppermost island to the bottom tip of the lowermost island following the thalweg and did not include side channels in the calculation. Reach lengths for sections that had split channels were measured from the top to the bottom of the split channel complex along the primary channel thalweg. Percentages were calculated by dividing the length of split channel into the total reach length. More information on this method can be found in Appendix D-2 - Transect Weighting Methods (Habitat Typing). Transect weighting tables are presented in Appendix D-3. 8.2 Habitat Duration Model 8.2.1 Description of Habitat Duration Model The WUA function is a static relationship between discharge and habitat and does not represent how often a specific flow/habitat relationship occurs. For this reason, WUA is generally not considered the final result of an instream flow study. The next step is the Habitat Duration Analysis (HDA). For the purposes of the HDA, WUA was extended 2.5 times beyond the highest measured flow to achieve the necessary range on the flow duration curve. This was achieved by using the trend line method where the habitat duration curve is extended to the 100th percentile based on the trend line created by the last two coordinate points. The extent of extrapolation for the Pee Dee River was determined by professional judgment of the IFSG. Frequency of habitat occurrence is derived from a habitat duration analysis. An HDA integrates WUA with hydrology and project operations to provide a dynamic analysis of flow versus habitat. A habitat duration curve is constructed in exactly the same way as a flow duration curve, but uses habitat values instead of discharges as the ordered data. Although habitat duration curves look similar to and are based on flow duration curves, there is no direct correspondence between the two curves. For example, the habitat value that is exceeded 90 percent of the time usually does not correspond to the discharge that has the same exceedance probability. This discordance happens because of the normal bell-shaped data relationship between total habitat and discharge (Bovee et al. 1998). 8.2.2 Habitat Duration Analysis Program Used DTA used its proprietary software program, “Flow Time Series” (written in Power Basic®), to run habitat duration analyses. The use of this program for the habitat duration analysis was reviewed and approved by the IFSG. Flow Time Series is a very flexible and fast program that allows the user to input all necessary data and then select which sets or sub-sets of data to use based on project operation specifics and analysis needs. The program creates individual files of all model runs. For a more detailed explanation of the habitat duration analysis and associated metrics refer to Appendix D-5.


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Input parameters can include: ■ Hydrologic record at specific nodes and at any time step desired (e.g., hourly, daily, weekly); ■ WUA by subreach for all aquatic species and life stages; and ■ Periodicity for each aquatic species life stage. Modeling options can include: ■ Multiple baseline and alternative flow scenarios; ■ A single reach or combined reaches; ■ Various methods for extrapolating beyond the highest modeled flow; ■ Set or subset of the hydrologic record; ■ Portion of the flow exceedance curve to use (any portion, full or trimmed data set); and ■ Output metric-index such as “Index C” or area under the habitat duration curve (AUC). 8.2.3 Hydrologic Data Sources For the Pee Dee River analysis, the HDA factored in four sources of flow in calculating habitat duration: (1) regulated instream flow releases at the dam; (2) spillage at the dam; (3) accretion or tributary/intervening watershed inflow between the dam and each hydrology node; and (4) unregulated flow at the dam. The 74-year period of record used in the analysis was January 1, 1930 to December 31, 2003, which is the same period of record being utilized for Project operations and basin hydrology models. Pee Dee River hydrology data files for the habitat duration analysis were constructed by DTA. Source hydrology for the habitat duration analysis was based on gage record pro-rationing techniques using numerous USGS gages in the Yadkin-Pee Dee River system. Mean daily flow records were drawn from source inputs for the Oasis and CHEOPS™ operations models used by APGI and Progress Energy, respectively. The data for each of the flow sources were derived as follows. 1. Regulated Releases - Regulated releases are the mean daily instream flows measured

immediately below each Project dam. Regulated releases were derived from Project operation discharge records and the Rockingham USGS gaging station immediately downstream from Blewett Falls Dam. Data was available in annual, monthly, daily, hourly, and 15-minute time steps for application as appropriate. A mean daily time step was chosen by the IFSG to represent the regulated releases.

2. Daily Spillage at Tillery Dam or Blewett Falls Dam - Daily spill is the mean daily uncontrolled flow past each Project dam. Mean daily spill was derived from Project operation discharge records for the Tillery and Blewett Falls developments. Spill was incorporated into the record of regulated releases.

3. Accretion Between Tillery Dam or Blewett Falls Dam and Each Hydrology Node - Mean daily inflow at each node was computed by adding synthesized mean daily accretion of the intervening drainage area between the node and the dam.

4. Unregulated Flow at Tillery and Blewett Falls Dams - Unregulated flow is the flow that would occur with all existing development in place, operating in a run-of-river (inflow equals


8-9

outflow) basis. Unregulated flow for the period of record below Tillery and Blewett Falls Dams were obtained from the Oasis and CHEOPS™ operations models used by APGI and Progress Energy, respectively.

8.2.4 Hydrologic Nodes A hydrologic node is a specific location (RM) where hydrology is calculated for the HDA. Identification of hydrologic nodes is necessary because river flow increases downstream as tributary inflow is added with increased river basin drainage area. Hydrologic nodes were developed at the midpoints within each subreach, unless unique aspects of a particular subreach warranted a different location. Node locations were determined in consultation with the IFSG and are shown below in Table 8-3. Table 8-3 Pee Dee Hydrologic Node Locations.

Reach/Subreach RM R1/SR1 107.8 R1/SR2 140.5 R2/SR1 168.9 R2/SR2 178.7 R2/SR3 186.3 R3/SR1 202.3 R3/SR2 209.6 R3/SR3 215.3

Daily hydrologic records at the hydrologic (flow) nodes were calculated as follows: ■ Existing Regulated - Daily existing regulated flow at each of the hydrologic nodes was

calculated as follows: DRF + DSPILL+ DACC Where: DRF = Daily Regulated Flow at the Dam DSPILL = Daily Spillage at the Dam DACC = Daily Accretion between the Dam and Hydrologic Node ■ Unregulated - Daily unregulated instream flow at each of the hydrologic nodes was

calculated as follows: DURF + DACC Where: DURF = Daily Unregulated Flow at the Dam DACC = Daily Accretion between the Dam and Hydrologic Node ■ Alternative Flow Regime - Daily alternative flow at each of the hydrologic nodes was

calculated as follows: DAF + DSPILL+ DACC


8-10

Where: DAF = Daily Alternative Flow at the Dam DSPILL = Daily Spillage at the Dam DACC = Daily Accretion between the Dam and Hydrologic Node

Note that the DAF in the habitat duration is modeled as a constant level flow release from the power plant 24 hours per day, 7 days per week. Peaking and load-following generation flows from the plant are not included in the DAF. Essentially, the DAF is a “base flow” that will be equaled or exceeded 100 percent of the time.

8.2.5 Model Runs The HDA was run as follows: ■ All guilds, species and life stages that were agreed upon during study plan development and

consultation; ■ Analysis time step was daily, and results time step was monthly; ■ All years in period of record were used; and ■ Output was both individual reaches and combined reaches below each development. 8.2.6 HDA Interactive Analytical Tool While habitat duration curves are one of the best means of comparing habitat availability over time between one flow scenario and another, the number of graphs required can become overwhelming as study variables become more numerous. For this reason, DTA did not generate individual habitat duration graphs for the potentially thousands of permutations possible given the large number of reaches and species, time steps (i.e., 12 months), and the range of possible flow scenarios. Not only is the production of the graphs a time consuming task, but the analysis of the potentially thousands of graphs would be extremely time consuming and cumbersome to analyze. For example, with 29 life stages or guilds, nine subreaches, 12 months, and a multitude of flow alternatives to test, the total number of output graphs required would exceed 100,000. To overcome the constraints of data overload, DTA developed a habitat duration interactive analytical tool that relies on the computer to store, calculate, and visually organize habitat duration results. This tool permits an effective reduction of data so analysis can be focused on specific instream flow study objectives. The program operates in a Microsoft Excel® spreadsheet format. It uses a metric of the habitat duration curve such as “Index C” or AUC (i.e., area under flow duration curve) to compare habitat availability over time between one flow scenario and another. For the Pee Dee instream flow studies, the IFSG selected Index C, a dimensionless value calculated as the mean of all habitat values occurring between 50 and 100 percent on the habitat duration curve) as the preferred habitat metric. Index C is a metric representing the lower range of the habitat duration curve and is thought to represent bottleneck or limiting habitat availability. Refer to Appendix D-5 for an explanation of the habitat duration method and Index C. The program calculates the metric by species, by month,


8-11

and by flow scenario. The tool is interactive and dynamic. The user can input any alternative flow regime for comparison to a baseline flow condition or to an alternative flow scenario. An annotated static example of a generic Interactive Spreadsheet is presented in Section 9.2.2. 8.3 Peaking Flow Analysis The Tillery Development is designed to be operated to meet peaking, load-following, and system support needs, whereas the Blewett Falls Development is operated as a peaking facility with block loading capability. This type of operation can result in relatively rapid changes in discharge from the Tillery Plant, while the Blewett Falls Plant’s units are either operating at best efficiency or are off. Blewett Falls acts to re-regulate discharges from Tillery, an important function in reducing the magnitude of the flow fluctuations downstream of Blewett Falls. The IFSG elected to use a Dual Flow Analysis as the primary tool for assessing the effects of peaking on the fishery resources. Although the Dual Flow Analysis, also known as the Effective Habitat Analysis (HABEF) program, was initially developed to quantify the effects of unsteady flow on spawning salmonid redds; it has since been used to evaluate the impacts of hydro-peaking on young fish and aquatic macroinvertebrates (Bovee 1985; Bovee et al. 1998). The original HABEF program was written in DOS PHABSIM (Milhous 1991) and is no longer supported. The Licensee used a program called the Dual Flow Analyzer developed by DTA as a replacement to the HABEF program. The use of this replacement software program was reviewed and approved by the IFSG. The underlying concept of the Dual Flow Analysis is that when flows fluctuate from a non-peaking to a peaking flow, a specific habitat cell is only suitable for a non-mobile organism as long as the conditions (i.e., depth and velocity) remain (at that specific cell) within the organism’s habitat preferences throughout the range of flows experienced by the organism. Effective habitat is calculated for each cell by comparing the suitability of the cell at each of two stream flows. In the overall comparison of the two discharges, a cell may be more suitable at a higher flow than at a lower flow, or vice versa. The Dual Flow Analyzer only records the lower (or effective) of the two paired values of the cell (e.g., overlapping habitat). If the habitat value is zero at either the low or high flow, it is not counted. The effective composite suitability is then multiplied by the cell’s surface area for the calculation of WUA. For the Pee Dee River, a range of peaking flows was compared to a range of minimum flows. For the peaking flows, the IFSG decided to use values the turbines could generate with one turbine at minimum capacity, one turbine at maximum efficiency, multiple turbines at maximum efficiency, and all turbines at maximum output. The range of minimum flows started at the current minimum instream flow or leakage up to 3,000 cfs in increments of 130 to 135 cfs. Non-mobile life stages in the subreaches closest to the dams were selected for the analysis (Table 8-4). Selected flows for analysis are shown below in Table 8-5.


8-12

Table 8-4 Life Stages Modeled in the Pee Dee River Dual Flow Analysis. Code Description Representative Lifestage

AMSS2 American Shad Spawning 2 BLUCY Shallow Slow Early Lifestage Bluehead Chub YOY RBSFS Shallow Slow Spawn Fine Substrate No Cover Redbreast Sunfish Spawning RORHS Robust Redhorse Spawning SRHYV Shallow Slow YOY Veg Cover Silver (Notchlip) Redhorse YOY Veg Cover SRHYW Shallow Slow YOY Wood Cover Silver (Notchlip) Redhorse YOY Wood Cover STBAI Striped Bass Incubation and Larval STBAS Striped Bass Spawning STUSI Sturgeon Spawning and Incubation WBASS Deep Fast Spawn Gravel, small Cobble White Bass Spawning EPHEM Ephemeroptera MACLR Macroinvertebrate Community Large Rivers PLECO Plecoptera TRIC1 Trichoptera 1 TRIC2 Trichoptera 2 and 3

Table 8.5 Peaking Flows and Range of Minimum Flows Chosen for Dual Flow

Analysis. Units Operating Mode Discharge (cfs)

Tillery Development 2 Minimum 1,500

1,2 Minimum 3,200 1 Efficiency 4,700

1,2 Efficiency 7,800 1,2,3 Efficiency 12,500

1,2,3,4 Efficiency 17,000 1,2,3,4 Maximum 20,500

Minimum flow range = 70 through 3,000 cfs at 130 cfs increments. Blewett Falls Development

1 Minimum 880 1 Efficiency 1200

1,2 Efficiency 2400 1,2,3 Efficiency 3600

1,2,3,4 Efficiency 4900 1,2,3,4,5 Efficiency 6200

1,2,3,4,5,6 Efficiency 7500 1,2,3,4,5,6 Maximum 8712

Minimum flow range = 150 through 3,000 cfs at 95 cfs increments. The range of peaking flows and minimum flows were entered into RHABSIM and cell detail reports were generated for all non-mobile life stages of concern. The reports contained a WUA value for each cell, transect, and life stage. With the aid of the program written by DTA, “Dual Flow Analyzer,” the comparison of WUA for different flows was compiled into condensed matrices that showed the resulting effective habitat for paired flows. Graphs were then created showing a comparison of different peaking curves. Results are presented in Section 9.3 and Appendix F-2.


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8.4 Wetted Perimeter and Mussel Transects A modeling approach using PHABSIM was not possible at all transects and for all species of interest. At two transects in Reach 1 (Transects T8 and T1), hydraulic conditions prevented habitat simulation with PHABSIM. For mussels, the lack of HSC criteria and other life history considerations presented an assessment of flow alternatives on mussel habitat using PHABSIM. Wetted perimeter or inundation analyses were applied in these situations. ■ Transect T8 - Reach 1, Subreach 1 - During the transect selection process in Reach 1

Subreach 1, the IFSG identified a unique backwater habitat and requested that a transect be placed at the feature (Transect T8). Further discussion regarding the distinctive hydraulics and the thick riparian vegetation on the transect resulted in the decision to measure and model it using the wetted perimeter method. A representative transect was established across the channel and backwater. The stage was measured at three different flows and the channel cross section was surveyed. The graphic results showing the relationship between discharge and inundation of the bed and banks can be found in Appendix E-1 - Wetted Perimeter.

■ Transect T1 - Reach 1, Subreach 1 - The initial attempts to model this transect in Subreach 1 using RHABSIM were unsuccessful due to the unique hydraulics and channel form present at the site. During model calibration consultation discussion with Mr. Jim Mead of the NCDWR and Mr. Thomas R. Payne of Thomas R. Payne and Associates, it was decided that this transect would be modeled using the wetted perimeter approach. A stage discharge relationship was generated in the hydraulic simulation (HYDSIM) module of RHABSIM and imported into an interactive graphic. A graphic illustration of the relationship between discharge, substrate, WSE, and wetted perimeter can be found in Appendix E-1.

■ Mussel Transects - The IFSG identified mussels as species of resource interest for instream flow needs. Because no mussel HSC currently exist for integration with PHABSIM, the IFSG agreed to conduct a wetted perimeter analysis for mussels at selected transects from the PHABSIM study. Acting on behalf of the IFSG, the NCWRC selected PHABSIM transects based on transects established and previously surveyed for mussels during the shallow water fish, mussel, and crayfish survey conducted by Progress Energy in 2004 as part of the required relicensing environmental study (Progress Energy 2005). Table 8-6 shows the PHABSIM transects where mussels were either found or would likely be found. The analysis would determine the instantaneous amount of wetted width that was created at any given flow and the amount of habitat (inundation over a preferred substrate) that these transects provided for mussels. Graphics in Appendix E-2 - Mussels, illustrate the relationship between discharge, substrate, WSE, and wetted perimeter.

Table 8-6 PHABSIM Transects Used for Mussel Analysis on the Pee Dee River.

Wetted Perimeter Mussel Analysis Reach Subreach PHABSIM Transect

1 3,5 1 2 1 6,9 2 3,6,7,8 2 3 2,8,9 1 3 2 3,4 3 3 7,8


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■ Programs Used - Interactive Microsoft Excel® charts were created to analyze the relationship

between discharge and inundation of suitable substrates for mussels at selected transects. Substrate data were incorporated into the charts as a visual bed profile and were derived from the PHABSIM substrate data collection. A stage/discharge relationship calculated from RHABSIM was used to illustrate a WSE change with an increase in discharge. Wetted perimeter was calculated for every WSE and displayed below the chart.

8.5 Navigation Model 8.5.1 Description of Navigation Model The navigation study was a component of the Pee Dee River Instream Flow Study. All sites were selected and surveyed in consultation with the SCDNR, NCDWR, and NCWRC. Agency personnel reviewed the Pee Dee River aerial video and identified potential navigation hazards. The selected navigation sites were verified in the field before navigation analysis was conducted. Table 8-7 lists the navigation study sites chosen for the Pee Dee River Instream Flow Study. Aerial video still photographs of each navigation site are found in Appendix C-2 - Navigation Transects. Table 8-7 Summary of Navigation Study Site Locations and Assessment Criteria.

Site RM Navigation Assessment Level1 Site Description

1 116.1 Two-Way Navigation Shoal upstream of Cashua Ferry boat landing at S.C. Highway 34 Bridge.

2 161.9 Two-Way Navigation Gravel bar at Thompson Creek confluence downstream of City of Cheraw public boat landing.

3 165.1 One-Way Navigation Shoal just above Cheraw at US Highway 1/S.C. Highway 9 Bridge.

5 183.4 One-Way Navigation Shoal and remnant prehistoric fishing weir downstream of N.C. Highway 74 Bridge.

6 184.8 Two-Way Navigation Shoal upstream of N.C. Highway 74 Bridge.

7 196.2 One-Way Navigation; Two-Way Navigation

Shoal at headwaters of Blewett Falls and upstream end of Grassy Islands area.

8 211.0 One-Way Navigation Remnant prehistoric fishing weir in main channel of the Leak Island complex

9 216.5 One-Way Navigation Old mill dam weir site approximately 1.5 miles below Tillery Dam. 1 All study sites were evaluated for fish passage criteria. The criteria for assessment of these navigation sites was based on criteria outlined for navigable waters in South Carolina (De Kozlowski 1988) as follows: ■ One-Way Navigation - Passage of a 14-ft jon boat without a motor in the downstream

direction only. Requires a depth of 1 ft for 10 percent of total stream width (minimum point of passage width of 10 ft).

■ Two-Way Navigation - Passage of a 14-ft jon boat with a motor in either direction. Requires a depth of 2 ft for 20 percent of total stream width (minimum point of passage width of 10 ft).

■ Fish Passage - Passage of a striped bass in an upstream direction. Requires a depth of 1.5 ft and a 10-ft point of passage width.


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8.5.2 Model Procedures Standard differential (X-Z) and coordinate plane (X-Y) surveying techniques were used at each transect (Figures 8-1 and 8-2). A total station survey instrument was used with temporary vertical and horizontal benchmarks to measure channel elevations and WSE. All streambed elevations were measured within the ordinary high-water width of the navigation transect. Vertical measurements were accurate to the nearest two-thousandths of a foot. A stage-discharge rating curve with at least a three-point regression was created at each navigation transect (Figure 8-3). All flow measurements were taken with an ADCP or extracted from a nearby USGS gaging station. Extrapolation of the stage-discharge rating curve was limited to 0.4 times the lowest measured flow and 2.5 times the highest measured discharge value. Navigation transect data was then entered into a Microsoft Excel® spreadsheet for criteria evaluation. An iterative process of entering WSE values was conducted until the minimum depth and width criteria were met. This process was completed for all navigation and fish passage transects. Results are presented in Section 9.5 and Appendix E-3.


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-250

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Lateral Distance (X)

Long

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nal D

ista

nce

(Y)

Navigation Transect Plan ViewFlow Direction

Figure 8-1 Pee Dee River Navigation Transect No. 9 (Reach 3, Subreach 3) (Old Mill

Dam Weir Site at RM 216.5) Plan View X-Y.

90.5

91.0

91.5

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-700 -650 -600 -550 -500 -450 -400 -350 -300 -250 -200 -150 -100 -50 0 50


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vatio

n (Z

)

Navigation Transect Profile

Figure 8-2 Pee Dee River Navigation Transect No. 9 (Reach 3, Subreach 3) (Old Mill

Dam Weir Site at RM 216.5) Profile View X-Y.


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y = 190.87x - 372.91R2 = 0.9996

2.00

2.20

2.40

2.60

2.80

3.00

3.20

1.9640 1.9650 1.9660 1.9670 1.9680 1.9690 1.9700 1.9710 1.9720

Log Stage (feet)

Log

Dis

char

ge (c

fs)

Figure 8-3 Navigation Transect No. 9 Stage - Discharge Relationship.

9-1

Section 9 - Results and Analysis Through a series of meetings with the IFSG3 between February and July 2005, Progress Energy and its consultant, DTA, presented the results of all instream flow assessment tools described herein. During this time and continuing through March 2006, IFSG members have analyzed these results for a multitude of alternative flow releases at each of the two hydroelectric developments. In many cases, the results were viewed and analyzed using interactive computer programs that allowed the IFSG to efficiently and effectively analyze the effect of alternative flow regimes on fish habitat. Progress Energy provided study data and all proprietary programs for use on a laptop personal computer to the NCDWR to enable independent evaluation of flow alternatives by resource agencies associated with the IFSG. It is important for those interested in this analysis phase of the instream flow study to recognize that the end result of an instream flow study is not a set value, but models of simulated ranges of values to be used as tools in concert with other analytical tools to evaluate the effect of alternative stream flows on Project operations and fish and aquatic habitat. Because the IFSG has not settled on a set of recommended flows at this time, Progress Energy has elected to demonstrate the kinds of results and analyses the IFSG has been using in its evaluation of minimum flows. For demonstration of the analytical tools, Progress Energy selected Subreach 3 of Reach 2 (immediately below Blewett Falls Dam) and flow release levels of 500 and 2,000 cfs. These two release scenarios are arbitrary and are presented here for explanation purposes only. They are not intended to represent any position of any party in the IFSG. In this section, we present the results and demonstration analysis for: 1) weighted useable area; 2) habitat duration; 3) peaking flow; 4) mussel habitat; and 5) navigation assessment. 9.1 Weighted Useable Area Using the program HABTAT, WUA was calculated for the 29 target species, life stages, and guilds. An example WUA chart and table are presented in Table 9-1 and Figure 9-1. WUA results for all target species, life stages, and guilds for all subreaches (140 graphs) are presented in digital format in Appendix F-4. The WUA tables and figures show the relationship between discharge and the availability of habitat for focus species in terms of square feet per 1,000 linear ft of stream. WUA is a static relationship, independent of how much water is actually in the channel at any given time. The WUA function is unaffected by alternative flow releases at the dam. In reality, river flow and WUA vary by season, by day, and by hour, depending on the amount of precipitation and resulting inflow and hydro operations. For this reason, WUA is generally considered a building block of instream flow analysis; not the final result. The Habitat Duration Analysis, described previously in Section 8.2.6, is the next step in instream flow analysis.

3 The IFSG officially disbanded after completion of the instream flow study in July 2005. The group was reformed in

August 2005 and termed a TWG of the Relicensing Settlement Group which began settlement discussions during this same period. The TWG is synonymous with the IFSG and has the same participating members, but its role is slightly different. This group’s charges have been evaluating various flow alternatives for use in making recommendations for instream flow releases from the Project.

Section 9 Results and Analysis

9-2

Table 9-1 Study Site 2 Subreach 3 WUA (sq ft per 1,000 ft) for Some Target Species.

Discharge American Shad

Spawning 2 (AMSS2)

Shallow Slow Early Lifestage

(BLUCY)

Deep Slow Generic with

Cover (DSLOC)

Golden Redhorse

Adult (GORHA)

Shallow Fast Adult Low

Velocity (MMADA)

Robust Redhorse Spawning (RORHS)

Striped Bass Spawning (STBAS)

150 4,727 75,645 186,746 91,342 75,058 0 0 210 10,750 63,228 191,066 97,171 90,356 0 3 270 18,137 57,362 195,794 102,658 102,006 0 25 330 26,169 51,083 199,534 107,719 110,055 67 102 390 34,767 45,196 203,852 112,341 115,453 67 251 450 43,574 39,864 205,805 116,582 119,116 67 448 510 52,353 36,153 209,443 120,496 121,120 134 720 570 61,134 32,006 212,075 124,177 121,937 201 1,099 630 69,888 27,926 214,422 127,565 121,759 752 1,583 700 80,033 23,734 217,252 131,256 120,562 819 2,251 780 91,567 19,988 220,300 135,189 118,037 1,516 3,135 860 102,698 16,621 221,503 138,808 114,585 1,819 4,102 940 113,338 14,842 224,234 142,059 110,622 1,886 5,161

1,020 126,353 11,668 226,909 145,990 112,619 2,113 5,528 1,100 140,280 9,323 231,679 149,797 113,568 2,798 5,850 1,200 157,720 6,915 235,591 153,964 111,946 2,605 6,468 1,320 173,376 6,091 240,094 157,362 102,906 3,420 8,623 1,440 187,876 5,320 243,677 160,367 94,227 5,657 11,118 1,560 201,137 5,372 246,091 163,118 85,967 6,985 13,,923 1,680 213,327 4,819 249,,953 165,536 78,405 7,412 16,965 1,740 218,979 4,553 249,289 166,721 74,829 7,531 18,559 1,800 224,363 4,310 248,729 167,802 71,432 8,017 20,212 1,880 231,107 4,046 249,451 169,155 67,029 7,975 22,484 1,980 238,969 3,843 251,231 170,680 61,829 8,024 25,407 2,080 246,215 3,711 250,473 172,088 57,049 8,100 28,597 2,180 252,795 3,443 250,110 173,351 52,652 8,144 31,927 2,280 258,836 3,367 249,333 174,454 48,610 8,144 35,361 2,380 264,406 3,235 247,441 175,538 44,910 8,533 38,901 2,480 269,521 3,239 244,364 176,458 41,526 8,522 42,542 2,580 274,293 3,294 244,917 177,312 38,480 8,522 46,378 2,680 278,774 3,249 243,223 178,056 35,727 8,129 50,477 2,780 285,763 3,224 236,258 179,253 33,650 8,244 54,134 2,880 292,473 3,059 231,428 180,397 31,579 8,628 57,766 2,980 298,945 3,180 228,880 181,457 29,569 8,941 61,472 3,080 305,133 3,494 224,233 182,524 27,630 9,380 65,320 3,180 311,081 3,282 221,831 183,504 25,767 9,587 69,319 3,380 319,529 3,397 217,708 184,779 22,276 9,821 78,390 3,580 324,431 3,179 215,621 185,453 19,312 9,695 88,521 3,780 328,675 3,345 211,514 185,980 16,936 9,576 98,832 3,980 332,368 3,538 202,894 186,258 15,023 9,523 109,302 4,180 335,383 3,398 186,142 186,518 13,506 9,,496 119,,828 4,580 339,717 3,317 164,165 186,747 11,237 9,298 140,825 4,980 342,752 2,905 155,844 186,638 9,542 7,366 161,655 5,380 344,835 2,829 148,030 186,406 8,167 7,030 182,314 5,780 345,956 2,769 137,709 185,862 7,031 6,494 202,714 6,180 346,150 2,341 130,690 185,209 6,083 5,603 222,752 6,780 345,061 2,885 117,516 184,072 4,929 2,642 251,119 7,380 342,826 3,183 103,999 182,654 4,018 1,684 277,347 7,980 339,503 3,450 91,860 181,169 3,297 532 299,983 8,580 335,314 3,353 81,604 179,645 2,706 242 319,432


9-3

Discharge American Shad

Spawning 2 (AMSS2)

Shallow Slow Early Lifestage

(BLUCY)

Deep Slow Generic with

Cover (DSLOC)

Golden Redhorse

Adult (GORHA)

Shallow Fast Adult Low

Velocity (MMADA)

Robust Redhorse Spawning (RORHS)

Striped Bass Spawning (STBAS)

9,180 330,362 2,984 75,419 178,023 2,210 484 336,974 9,780 324,725 2,955 72,165 176,303 1,792 242 352,854

10,380 318,428 2,749 68,198 174,481 1,440 242 367,043 11,125 309,936 2,532 61,716 172,166 1,102 0 382,548 11,870 300,696 2,746 59,288 169,775 904 0 395,924 12,615 290,688 2,433 59,002 167,486 765 0 407,616 13,360 280,103 2,338 57,488 165,115 635 0 417,411 14,105 268,890 1,934 56,657 162,807 526 0 425,784 14,850 257,287 1,921 55,336 160,413 447 0 432,584 15,595 244,250 2,484 55,357 157,948 360 0 437,989 16,635 230,009 2,879 54,302 154,981 260 0 443,294

Pee Dee River Weighted Useable AreaReach 2 - Subreach 3 - Some Focus Species/Lifestages

0

50000

100000

150000

200000

250000

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350000

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0 2000 4000 6000 8000 10000 12000 14000 16000

Discharge

Wei

ghte

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0 fe

et o

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AMSS2 BLUCY DSLOC GORHA MMADA RORHS STBAS

Figure 9-1 Example Weighted Usable Area Chart for Some Target Species in the Pee Dee River.

Legend Acronym Species or Guild Legend Acronym Species or Guild AMSS2 American Shad Spawning BLUCY Shallow Slow Early Lifestage DSLOC Deep Slow Generic - Cover GORHA Golden Redhorse Adult MMADA Shallow Fast Adult Lower Velocity RORHS Robust Redhorse Spawning STBAS Striped Bass Spawning


9-4

9.2 Habitat Duration Analysis The ability of an alternative flow to provide increased habitat relative to baseline flow condition is best determined by comparing the total amount of habitat available under the alternative with the total amount of habitat available under the baseline condition. The basic tool for quantifying differences between an alternative and baseline conditions is habitat duration (Bovee 1998). The habitat duration quantifies total habitat by integrating WUA with basin hydrology and Project operations. 9.2.1 Habitat Duration Results Example results from the habitat duration model are presented below. Examples, rather than actual results, are presented for two reasons: 1) presentation of all the species, months, subreaches, and possible flow alternatives would require innumerable graphs and tables; and 2) as of the writing of this report, the final preferred flow alternatives have not been settled by the IFSG. Figure 9-2 is a habitat duration plot at Reach 2, Subreach 3 for the deep slow guild for the months of April and September. Represented are two different “alternative minimum flow release” scenarios from Blewett Falls Dam; 500 and 2,000 cfs. These two release scenarios are arbitrary and for explanation purposes only. Also shown on the plots is the habitat duration for the unregulated flow. As stated previously in Section 8.2.4, the alternative release scenarios depict a constant-level base flow release from the power plant 24 hours per day, 7 days per week. Generation flow in excess of base flow is not included in the alternative release. Essentially, the alternative release is a “minimum flow” that would be equaled or exceeded 100 percent of the time under actual conditions. There are pros and cons to discounting the effects of variable peaking or load-following discharges on habitat in the analysis. Some IFSG members argued that variable generation flows above the minimum flow should not be included since they are dependent on electrical demand and availability cannot be “guaranteed” in the license. The rationale put forth behind this approach was that base flow conditions represented the “worst case scenario” especially for river reaches immediately below the Project dams and for species with low mobility. Other members argued that generation flow should be included because those are the flows that would actually be in the river. The logic behind this approach is that as one proceeds downstream of the Project dams, generation flow variability attenuates with increasing distance downstream and more and more of the generation flow is available continuously and effectively adds to the minimum base flow. There were other arguments for and against the inclusion of variable generation discharges in the habitat duration analysis. However, it was recognized by all IFSG members that in order to include variable generation flow in the habitat duration analysis, spatial and temporal flow variation would need to be incorporated into the hydrograph through use of an unsteady state flow routing model at each hydraulic node. This would increase model complexity by several orders of magnitude. In the end, the IFSG did not include variable generation discharge in the habitat duration model analysis. The Licensee stated that this approach would consistently bias habitat analysis towards the lower range of the flow hydrograph and that this bias increased with increasing distance downstream.


9-5

April

0

0.5

1

1.5

2

2.5

3

3.5

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0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

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Percent of Time Habitat Equalled or Exceeded

Tota

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500 cfs 2000 cfs Unregulated

September

0

0.5

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1.5

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2.5

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3.5

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0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

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Tota

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500 cfs 2000 cfs Unregulated

Figure 9-2 Pee Dee River Habitat Duration - Reach 2, Subreach 3 - Deep Slow Generic Lifestage with Cover.


9-6

In reviewing Figure 9-2, please note that there is little if any difference in habitat duration between the 500 or 2,000 cfs curves for April and September. The reason for this is the very small difference in accretion between April and September between the dam (at RM 188.2) and the Subreach 3 hydrology node (RM 186.3). Note also that the habitat duration curves under the unregulated flow are different between months because the entire basin hydrology above the study site is used in the model. Finally, note that more habitat is created in September for the deep slow guild than is created in April. It appears that that higher flow in April diminishes overall habitat availability for this guild (see WUA curve in Figure 9-1). Habitat duration graphs were requested by the IFSG for Reach 2, Subreach 3 and are presented in Appendix F-3. While examination of habitat duration graphs provide a visual reference for habitat gains or losses under different flow scenarios, one cannot quantify these differences by simply looking at the graphs. To quantitatively compare habitat durations between two alternative flows or an alternative flow and a baseline flow, a metric must be used. One metric is total area under the curve. Another metric, the one used by the IFSG, is Index C and is explained in Section 8.2.6 and Appendix D-5. Because graphics are not quantitative, the IFSG used other analytical tools as described in Section 9.2.2 as the primary means of analyzing habitat duration results. 9.2.2 Habitat Duration Analysis As described in Section 8.2.6, DTA developed the Habitat Duration Interactive Analytical Tool to help evaluate the effect of alternative flow releases on fish habitat. This computer tool is necessary to manage, organize, and store the enormous number of possible permutations of species and life stages, time period, river reach, and flow alternatives that must be evaluated in the Pee Dee River instream flow study. Figure 9-3 shows an example of output that explains how the Interactive Tool works and how to read it. The primary metric used by the IFSG to evaluate one habitat duration versus another is Index C. Index C produced by an alternative flow release was calculated and compared to Index C relative to the three benchmarks as described below. Standards for each type of benchmark are not absolute; they merely serve as guidelines. ■ Percent of Maximum Index C Achievable

(NCDWR Guideline commonly ranges from 70 to 80 percent). ■ Percent of Index C Compared to Index C under Unregulated Flow Conditions

(NCDWR generally uses a guideline of 80 percent) ■ Percent of Index C Compared to Index C under Existing Flow Conditions

(No guideline - Generally improvement is desired) Figures 9-4 and 9-5 are printouts of the Interactive Analytical Tool showing habitat duration results (Index C) for combined subreaches for Reach 2 for seven of the 29 target species at flows of 500 and 2,000 cfs, respectively. These seven species were arbitrarily selected for demonstration purposes only. They do not represent species of any special concern. The two release scenarios (500 and 2,000 cfs) are arbitrary and are also presented here for explanation purposes only.


9-7

Each page of the Interactive Analytical Tool is one of hundreds of pages of output. In this case, Figure 9-3 shows the effect of a 2,000 cfs flow on Index C for each month for the three subreaches combined for Reach 2. The upper half of the table shows the level of Index C for a 2,000 cfs flow compared to the maximum achievable Index C. For example, in March, a flow of 2,000 cfs produces an Index C value of 323,026 for American shad spawning. This Index C value is 82.5 percent of the maximum achievable Index C in March. The lower half of Figure 9-3 shows the level of Index C for a 2000 cfs flow compared to the level of Index C under the unregulated flow condition. For example, in March a flow of 2,000 cfs produces an Index C value of 261,478 for American shad spawning. This Index C value is 123.5 percent of the level that would be produced under an unregulated flow. Resource agencies of the IFSG focused the analysis of alternative instream flows on seven “Driver Species/Lifestages”. Driver species/lifestages were those seven species that required the highest discharge to meet 80 percent of the unregulated flow Index C. Resource agencies of the IFSG also focused the analysis of instream flows on the subreach immediately below the Project dams, where accretion is least and low flow impacts may be the greatest. 9.3 Dual Flow Results The IFSG chose to conduct the dual flow analysis only in the sub-reaches immediately below the two developments because this is where the impacts of peaking would be greatest. Figures 9-6 and 9-7 present example dual flow results for the deep fast spawning guild and American shad spawning below Blewett Falls Dam. Results for all 15 non-mobile life stages for below both developments are presented in Appendix F-2 As stated previously in Section 8.3, effective habitat is calculated for each PHABSIM cell by comparing the suitability of the cell at each of two stream flows; the non-peaking and the peaking flow. In the overall comparison of the two flows, a cell may be more suitable at a higher flow than at a lower flow, or vice versa. The Dual Flow Analyzer only records the lower (or effective) of the two paired values of the cell (e.g., spatially overlapping habitat). If the habitat value is zero at either the low or high flow, it is not counted. The effective composite suitability is then multiplied by the cell’s surface area for the calculation of WUA. These data can then be graphed as shown above in Figures 9-6 and 9-7. Figure 9-6 shows that in a peaking scenario habitat is most available if the maximum peak is around 3,600 cfs. Habitat is least available if the peak is 8,712 cfs. Figure 9-7 shows that peaking has little if any diminishing effect on habitat for American shad spawning.


9-8

Main 1 2000 cfs Year Round Red = Less than 70%

11.4% 99.9% 89.5% 39.5%12.1% 100.0% 89.7% 38.4%

82.5% 12.5% 100.0% 89.9% 38.0%81.4% 11.6% 99.9% 89.4% 39.5% 98.8% 12.2%79.5% 9.3% 99.5% 88.8% 43.1% 99.4% 11.2%

8.8% 99.5% 44.4% 99.5% 11.0%9.0% 99.5% 88.6% 44.1%9.3% 99.6 43.5%9.2% 99.6% 44.0%9.0% 99.6% 88.5% 44.5%8.9% 99.5% 88.6% 44.0%9.8% 99.6% 89.0% 42.2%

% % 89.0% 42.1% 99.2% 11.4%

Combined arison to Maximum SR3/SR2/SR1 Pee Dee Reach 2 - Regulated Comp Combined SR3/SR2/SR1

% of % of % % of % o % of % of of fFlow Month Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max2000 Jan NA NA 3,007 74,234 78,103 44,761 NA NA NA NA2000 Feb NA NA 2,955 74,177 78,321 42,461 NA NA NA NA2000 Mar 323,026 2,947 74,200 78,469 41,393 NA NA NA NA2000 Apr 319,360 3,003 74,111 78,039 44,214 47,954 48,3382000 May 314,458 3,061 74,047 77,479 51,787 49,514 44,4882000 Jun NA NA 3,074 74,064 77,348 88.6% 54,118 49,903 43,6252000 Jul NA NA 3,059 74,025 77,302 52,970 NA NA NA NA2000 Aug NA NA 3,057 74,043 % 77,313 88.6% 51,912 NA NA NA NA2000 Sep NA NA 3,049 73,935 77,283 88.6% 52,018 NA NA NA NA2000 Oct NA NA 3,044 73,993 77,262 53,020 NA NA NA NA2000 Nov NA NA 3,066 74,036 77,369 53,367 NA NA NA NA2000 Dec NA NA 3,047 74,072 77,672 49,704 NA NA NA NA

Average: 81.1 10.1% 99.7

2000 cfs Year R

Am Shad Spawn2 SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

o 0 Blue = Greater than 99.9%

% of Re of Re of of Re of of of RegMonth Index C to Unreg Index C to Unreg Index C to Unreg Index C to Unreg Index C to Unreg Index C to Unreg Index C to Unreg

Jan NA NA 3,168 42,981 106,164 1,604 NA NA NA NAFeb NA NA 3,163 38,543 102,595 1,023 NA NA NA NAMar 261,478 3,180 37,694 101,530 913 NA NA NA NAApr 309,654 3,161 43,231 109,664 1,624 1,871 210,486May 371,912 3,162 61,009 120,329 4,191 6,303 132,220Jun NA NA 3,175 71,876 103.0% 119,989 64.5 6,844 11,192 94,882Jul NA NA 3,198 80,805 117,366 9,669 NA NA NA NAAug NA NA 3,212 84,486 87.6% 115,593 66.9% 11,636 NA NA NA NASep NA NA 3,339 96,585 76.5% 112,934 68.4% 19,413 NA NA NA NAOct NA NA 3,384 92,161 80.3% 109,885 70.3% 18,110 NA NA NA NANov NA NA 3,209 83,977 88.2% 117,058 66.1% 11,387 NA NA NA NADec NA NA 3,174 59,223 125.1% 116,937 66.4% 3,873 NA NA NA NA

Average:

Combined SR3/SR2/SR1 Pee Dee Reach 2 - Comparison to Un Combined SR3/SR2/SR1Red = Less than 80%

94.9% 172.7% 73.6% 2791.4%93.4% 192.5% 76.3% 4150.4%

123.5% 92.7% 196.8% 77.3% 4531.7%103.1% 95.0% 171.4% 71.2% 2722.2% 2563.3% 23.0%84.6% 96.8% 121.4% 64.4% 1235.8% 785.5% 33.6%

96.8% % 790.7% 445.9% 46.0%95.7% 91.6% 65.9% 547.8%95.2% 446.1%91.3% 268.0%90.0% 292.8%95.6% 468.7%96.0% 1283.3%

103.7% 94.4% 125.6% 69.3% 1627.4% 1264.9% 34.2%

regulated

g % g % Reg % g % Reg % Reg %Am Shad Spawn2 SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

Changeable Minimum Instream Flow Regimes

Changing these values would change the Index C results to the right and the

percentages in the table below.

Index C

Index e mean of all the vafrom the 50th percentile to the 100thpercentile under a habitat duration

curve.

Percent of Maximu dex C

is shows the compar Index C at 2000 cfs in March to the maximum

achievable Index C

m In

Th ison of

C is th lues

Percen egulated to Unregu

The Unregulated C value to the left is c ared to the Regulated Index C value in the table above at the same position.

This percentage shows that the Regulated Index C is lower in March with a minimum flow regime of 2000 cfs than in an

Unregulated flow condition for the same time period for this lifestage.

t of R lated

Index omp

Figure 9-3 Illustration of the Habitat Duration Interactive Analytical Tool.


9-9

Main 1 Option 1 500 CFS for all Months Red = Less than 70%

59.2% 81.5% 58.5% 98.7%58.3% 82.4% 59.4% 97.4%

33.6% 58.1% 82.8% 60.1% 96.6%30.1% 59.2% 81.5% 58.2% 98.7% 25.8% 1.0%25.5% 59.5% 79.9% 55.8% 99.8% 22.4% 0.6%

60.0% 79.4% 55.2% 98.9% 21.7% 0.5%60.0% 79.4% 55.0% 99.1%59.6% 79.5% 55.1% 99.3%60.0% 79.5% 55.0% 99.0%60.2% 79.4% 54.9% 98.8%59.7% 79.5% 55.3% 99.0%59.1% 80.4% 56.7% 100.0%

29.8% 59.4% 80.4% 56.6% 98.8% 23.3% 0.7%

Red = Less than 80%

491.7% 141.0% 48.1% 6973.2%449.0% 158.5% 50.5% 10516.8%

50.4% 429.5% 163.0% 51.6% 11522.1%38.2% 485.2% 139.8% 46.3% 6806.3% 670.0% 1.8%27.1% 619.4% 97.4% 40.5% 2860.3% 176.8% 1.8%

661.2% 82.3% 40.2% 1760.7% 97.2% 2.3%636.1% 73.1% 40.9% 1231.4%612.7% 70.0% 41.6% 1017.5%596.6% 61.1% 42.5% 602.8%604.5% 64.0% 43.6% 650.0%639.6% 70.5% 41.2% 1055.7%580.4% 100.9% 42.3% 3044.6%

38.6% 567.2% 101.8% 44.1% 4003.4% 314.7% 2.0%

regulated

Combined SR3/SR2/SR1 Pee Dee Reach 2 - Regulated Comparison to Maximum Combined SR3/SR2/SR1

% of % of % % of % o % of % of

g % g % Reg % g % Reg % Reg %Am Shad Spawn2

of fFlow Month Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max500 Jan NA NA 15,578 60,582 51,027 111,816 NA NA NA NA500 Feb NA NA 14,203 61,100 51,849 107,593 NA NA NA NA500 Mar 131,772 13,657 61,437 52,415 105,244 NA NA NA NA500 Apr 118,325 15,338 60,448 50,794 110,549 12,534 3,867500 May 100,820 19,588 59,437 48,710 119,864 11,147 2,394500 Jun NA NA 20,991 59,155 48,204 120,510 10,874 2,164500 Jul NA NA 20,340 59,073 48,029 119,070 NA NA NA NA500 Aug NA NA 19,680 59,110 48,074 118,400 NA NA NA NA500 Sep NA NA 19,919 59,031 47,954 117,012 NA NA NA NA500 Oct NA NA 20,454 58,983 47,871 117,715 NA NA NA NA500 Nov NA NA 20,521 59,190 48,284 120,210 NA NA NA NA500 Dec NA NA 18,421 59,784 49,446 117,920 NA NA NA NA

Average:

Option 1 500 CFS for all Months Blue = Greater than 99.9%


Jan NA NA 3,168 42,981 106,164 1,604 NA NA NA NAFeb NA NA 3,163 38,543 102,595 1,023 NA NA NA NAMar 261,478 3,180 37,694 101,530 913 NA NA NA NAApr 309,654 3,161 43,231 109,664 1,624 1,871 210,486May 371,912 3,162 61,009 120,329 4,191 6,303 132,220Jun NA NA 3,175 71,876 119,989 6,844 11,192 94,882Jul NA NA 3,198 80,805 117,366 9,669 NA NA NA NAAug NA NA 3,212 84,486 115,593 11,636 NA NA NA NASep NA NA 3,339 96,585 112,934 19,413 NA NA NA NAOct NA NA 3,384 92,161 109,885 18,110 NA NA NA NANov NA NA 3,209 83,977 117,058 11,387 NA NA NA NADec NA NA 3,174 59,223 116,937 3,873 NA NA NA NA

Average:

Combined SR3/SR2/SR1 Pee Dee Reach 2 - Comparison to Un Combined SR3/SR2/SR1SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

Am Shad Spawn2 SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

Figure 9-4 Static Version Example of the Interactive Analytical Tool at 500 cfs Release.


9-10

Main 1 Option 2 2000 CFS for All Months Red = Less than 70%

11.4% 99.9% 89.5% 39.5%12.1% 100.0% 89.7% 38.4%

82.5% 12.5% 100.0% 89.9% 38.0%81.4% 11.6% 99.9% 89.4% 39.5% 98.8% 12.2%79.5% 9.3% 99.5% 88.8% 43.1% 99.4% 11.2%

8.8% 99.5% 88.6% 44.4% 99.5% 11.0%9.0% 99.5% 88.6% 44.1%9.3% 99.6% 88.6% 43.5%9.2% 99.6% 88.6% 44.0%9.0% 99.6% 88.5% 44.5%8.9% 99.5% 88.6% 44.0%9.8% 99.6% 89.0% 42.2%

81.1% 10.1% 99.7% 89.0% 42.1% 99.2% 11.4%

Red = Less than 80%

94.9% 172.7% 73.6% 2791.4%93.4% 192.5% 76.3% 4150.4%

123.5% 92.7% 196.8% 77.3% 4531.7%103.1% 95.0% 171.4% 71.2% 2722.2% 2563.3% 23.0%84.6% 96.8% 121.4% 64.4% 1235.8% 785.5% 33.6%

96.8% 103.0% 64.5% 790.7% 445.9% 46.0%95.7% 91.6% 65.9% 547.8%95.2% 87.6% 66.9% 446.1%91.3% 76.5% 68.4% 268.0%90.0% 80.3% 70.3% 292.8%95.6% 88.2% 66.1% 468.7%96.0% 125.1% 66.4% 1283.3%

103.7% 94.4% 125.6% 69.3% 1627.4% 1264.9% 34.2%

regulated

% of % of % % of % o % of % of

g % g % Reg % g % Reg % Reg %Am Shad Spawn2

of fFlow Month Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max Index C Max2000 Jan NA NA 3,007 74,234 78,103 44,761 NA NA NA NA2000 Feb NA NA 2,955 74,177 78,321 42,461 NA NA NA NA2000 Mar 323,026 2,947 74,200 78,469 41,393 NA NA NA NA2000 Apr 319,360 3,003 74,111 78,039 44,214 47,954 48,3382000 May 314,458 3,061 74,047 77,479 51,787 49,514 44,4882000 Jun NA NA 3,074 74,064 77,348 54,118 49,903 43,6252000 Jul NA NA 3,059 74,025 77,302 52,970 NA NA NA NA2000 Aug NA NA 3,057 74,043 77,313 51,912 NA NA NA NA2000 Sep NA NA 3,049 73,935 77,283 52,018 NA NA NA NA2000 Oct NA NA 3,044 73,993 77,262 53,020 NA NA NA NA2000 Nov NA NA 3,066 74,036 77,369 53,367 NA NA NA NA2000 Dec NA NA 3,047 74,072 77,672 49,704 NA NA NA NA

Average:

Option 2 2000 CFS for All Months Blue = Greater than 99.9%


Jan NA NA 3,168 42,981 106,164 1,604 NA NA NA NAFeb NA NA 3,163 38,543 102,595 1,023 NA NA NA NAMar 261,478 3,180 37,694 101,530 913 NA NA NA NAApr 309,654 3,161 43,231 109,664 1,624 1,871 210,486May 371,912 3,162 61,009 120,329 4,191 6,303 132,220Jun NA NA 3,175 71,876 119,989 6,844 11,192 94,882Jul NA NA 3,198 80,805 117,366 9,669 NA NA NA NAAug NA NA 3,212 84,486 115,593 11,636 NA NA NA NASep NA NA 3,339 96,585 112,934 19,413 NA NA NA NAOct NA NA 3,384 92,161 109,885 18,110 NA NA NA NANov NA NA 3,209 83,977 117,058 11,387 NA NA NA NADec NA NA 3,174 59,223 116,937 3,873 NA NA NA NA

Average:

Combined SR3/SR2/SR1 Pee Dee Reach 2 - Comparison to Un Combined SR3/SR2/SR1SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

Combined SR3/SR2/SR1 Pe arison to Maximum e Dee Reach 2 - Regulated Comp Combined SR3/SR2/SR1Am Shad Spawn2 SS Y Early LS DS Gen Cov Gldn Redhorse Adlt SF A Low Vel Robst Redhors Spn Striped Bass Spn

Figure 9-5 Static Version Example of the Interactive Analytical Tool at 2,000 cfs Release.


9-11

0

25

50

75

100

70 320 570 820 1070 1320 1570 1820 2070 2320 2570 2820 3070

Thou

sand

s

Minimum Discharge (cfs)

Wei

ghte

d U

sabl

e A

rea

(Sq

Ft /

1000

Lin

ear F

t of S

trea

m)

880 1200 2400 3600 4900 6200 7500 8712 Figure 9-6 Pee Dee River Reach 2, Subreach 3 Hydro Dual Flow Analysis Deep Fast

Spawn Gravel, Small Cobble.

0

50

100

150

200

250

300

350

70 320 570 820 1070 1320 1570 1820 2070 2320 2570 2820 3070

Thou

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Minimum Discharge (cfs)

Wei

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d U

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(Sq

Ft /

1000

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880 1200 2400 3600 4900 6200 7500 8712 Figure 9-7 Pee Dee River Reach 2, Subreach 3 Hydro Dual Flow Analysis American

Shad Spawning 3. 9.4 Wetted Perimeter and Mussel Transect Results As explained in Section 8.4, wetted perimeter analyses were conducted at IFIM Transects T1 and T8 in Reach 1 and at several transects selected for evaluation of flow impacts on mussels. All wetted perimeter results are presented in Appendix E-2.


9-12

Wetted perimeter results for mussel were presented to the IFSG in an interactive Excel spreadsheet. An example static version of one transect in Reach 2, Subreach 3 is shown below at flows of 500 and 2,000 cfs. Note that these flow levels were arbitrarily chosen for illustration purposes only and do not constitute any recommended flow release. All mussel wetted perimeter results at flows of 500 and 2,000 cfs are presented in Appendix E-2. Wetted perimeter at mussel transects for recommended settlement flows will be presented as necessary in the final relicensing settlement agreement. Figure 9-8 shows that the cross-sectional bed profile at Transect T9 in Reach 2, Subreach 3 is nearly entirely covered with water at both 500 and 2,000 cfs. Average depth is approximately 1 ft greater and wetted perimeter is 26 ft greater at 2,000 cfs than at 500 cfs. In the interactive version, the IFSG could manipulate the flow to analyze wetted perimeter and coverage of preferred substrates used by different mussel species. 9.5 Navigation and Fish Passage Results Navigation transect data were entered into an Microsoft Excel® spreadsheet for criteria evaluation. An iterative process of entering WSE values was conducted until the minimum depth and width criteria were met for navigation and/or fish passage as described in Section 8.5 above. This process was completed for all navigation transects. Figure 9-9 shows an example of results for navigation at Transect No. 9 at Reach 2 Subreach 3. Note that flows indicated as necessary for fish navigation are based strictly on field survey results and the stage/discharge regression. Table 9-2 shows initial results for all navigation study transects. Note that the IFSG will analyze each of these flow/channel response functions in conjunction with their professional judgment, local knowledge, and experience to arrive at recommended base flows that assures recreational boating navigation and fish passage within the Project affected areas.


9-13

Figure 9-8 Example Static Version of Wetted Perimeter Analysis Tool for the Pee Dee

River. Instream Flow Mussel Study. Note: Water Levels Modeled are 2,000 and 500 cfs.


9-14

90.5

91.0

91.5

92.0

92.5

93.0

93.5

94.0

94.5

-700 -650 -600 -550 -500 -450 -400 -350 -300 -250 -200 -150 -100 -50 0 50


Vert

ical

Ele

vatio

n (Z

)

Navigation Transect Profile

One-Way Navigation Slot (68 ft) = 367 cfs

Figure 9-9 Pee Dee River navigation and fish passage Transect No. 9 (Reach 3, Subreach 3) (Old Mill Dam Weir Site at RM 216.5) profile view X-Y.

Table 9-2 Summary of preliminary flow requirements at navigation study sites for the

Pee Dee River.

Navigation Site River Mile Assessment Level Minimum Flow (cfs)

Two-Way Navigation 1,801 1 116.1 Fish Passage < 495*

Two-Way Navigation 1,530 2 161.9 Fish Passage 800

One-Way Navigation 1,762 3 165.1 Fish Passage 303

One-Way Navigation 2,550 5 183.4 Fish Passage 3,460

Two-Way Navigation 3,560 6 184.8 Fish Passage 534

One-Way Navigation 205 Two-Way Navigation 5,395 7

196.2

Fish Passage <136 * One-Way Navigation 671 8 211.0

Fish Passage 562 One-Way Navigation 367 9 216.5

Fish Passage 359 * Flow value beyond the reliable extrapolation point of stage-discharge rating curve.

10-1

Section 10 - Literature Cited Aadland, L.P., C.M. Cook, M.T. Negus, H.G. Drewes, and C.S. Anderson. 1991. Microhabitat

preferences of selected stream fishes and a community-oriented approach to instream flow assessments. Minnesota Department of Natural Resources Fisheries Investigation Report No. 406.

Appalachian State University. 1999. North Carolina’s Central Park: Assessing Tourism and

Outdoor Recreation in the Uwharrie Lakes Region. September 1999. Beal, R., K. McKown, G. Shepard, and W. Laney. 2000. 2000 review of the Atlantic States Marine

Fisheries Commission fishery management plan for Atlantic striped bass (Morone saxatilis). Becker, G.C. 1983. Fishes of Wisconsin. The University of Wisconsin Press, Madison, Wisconsin. Bovee, K. 1982. A guide to stream habitat analysis using the instream flow incremental

methodology. Instream Flow Information Paper No. 12. FWS/OBS-82/26. U.S. Fish and Wildlife Service, Office of Biological Services, Fort Collins, Colorado.

Bovee, K.D., B.L. Lamb, J.M. Bartholow, C.B. Stalnaker, J.Tayler and J. Henriksen. 1998. Stream

habitat analysis using the instream flow incremental methodology. U.S. Geological Survey, Biological Resources Division Information and Technology Report USGS/BRD-1998-0004. viii + 131 pp.

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curves. Model I: Shortnose sturgeon, Model II: Atlantic sturgeon, Southeastern Atlantic Coast River Basins, Draft, April 20, 2001. Edited by P.H. Brownell, National Marine Fisheries Service, Charleston, South Carolina.

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Section 10 Literature Cited

10-2

Electric Power Research Institute. 1999. American eel (Anguilla rostrata) scoping study. A literature review of life history, stock status, population dynamics, and hydroelectric impacts. TR-111873, Final Report, March 1999.

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redhorse, Moxostoma robustum. A report to the U.S. Fish and Wildlife Service, January 2001.

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index curves: white bass. U.S. Fish and Wildlife Service Biological Report 82(10.89), December 1984.

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Roanoke River, North Carolina. Pages 193-200 in K. E. Limburg and J. R. Waldman (eds.). Biodiversity, status, and conservation of the world’s shads. American Fisheries Society Symposium 35, American Fisheries Society, Bethesda, Maryland.

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manual–version II. U.S. Fish and Wildlife Service Biological Report 89(16). Washington, D.C.

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D.D. Darling, editor. Proceedings of the International Conference on Hydropower, American Society of Civil Engineers, New York.

Morlock, S.E. 1996. Evaluation of Acoustic Doppler Current Profiler measurements of river

discharge. USGS Water-Resources Investigations Report 95-4218. Indianapolis, Indiana. 41 pp.


10-3

National Marine Fisheries Service. 1998. Recovery plan for the shortnose sturgeon (Acipenser brevirostrum). Prepared by the Shortnose Sturgeon Recovery Team for the National Marine Fisheries Service, Silver Spring, Maryland.

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——. 2005. Shallow water fish, crayfish, and mussel surveys of the Pee Dee River and tributaries.

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stage and discharge. USGS Water Supply Paper 2175. 284 pp. Rhode, F.C., R.G. Arndt, D.G. Lindquist, and J.F. Parnell. 1994. Freshwater fishes of the

Carolinas, Virginia, Maryland, and Delaware. The University of North Carolina Press, Chapel Hill, North Carolina.

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minutes, June 13, 2002.


10-4

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curves: American shad. U.S. Department of Interior, Fish and Wildlife Service Biological Report 82(10.88), June 1985.

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States Marine Fisheries Commission fishery management plan for shad and river herring (Alosa). Atlantic States Marine Fisheries Commission.

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Stirratt, H.M., P. Perra, T. Smith, K. McKown, and D. St. Pierre. 2000b. 2000 review of ASMFC

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Simulation System of the Instream Flow Group, U.S. Fish and Wildlife Service, Fort Collins, Colorado.

U.S. Department of Agriculture. 2002. U.S. Department of Agriculture, Natural Resources

Conservation Service Website. ——. 2001. U.S. Department of Agriculture, Uwharrie National Forest Recreation Opportunity

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National Wildlife Refuge, Refuge Objectives. http://peedee.fws.gov/. ——. 2006. U.S. Fish and Wildlife Service, National Marine Fisheries Service, North Carolina

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APPENDICES

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