Unimpaired Flow Data Report Surface Water Availability Modeling and Technical Analysis for Statewide Water Management Plan Prepared for: Georgia Department of Natural Resources Prepared by: ARCADIS U.S., Inc. 2849 Paces Ferry Road Suite 400 Atlanta Georgia 30339 Tel 770.431.8666 Fax 770.435.2666 Our Ref.: GA063853/Rpt 2514 Date: April 12, 2010 This document is intended only for the use of the individual or entity for which it was prepared and may contain information that is privileged, confidential and exempt from disclosure under applicable law. Any dissemination, distribution or copying of this document is strictly prohibited. Table of Contents Executive Summary 1 1. Introduction 4 1.1 Need for Unimpaired Flows 4 1.2 Basic and Planning Node Selection 4 2. General Procedures for Unimpaired Flow Development 10 2.1 General Description of Unimpaired Flow Process 10 2.1.1 Reach Cases 11 2.2 Data Inventory and Management 12 2.2.1 Water Use Data 12 2.2.2 Streamflow Data 13 2.2.3 Routing Model Parameterization 13 2.2.4 Reservoir Physical and Operational Data 14 2.2.5 Reservoir Meteorological Data 14 2.2.5.1 Precipitation 15 2.2.5.2 Evaporation Time Series Development 25 2.2.5.3 Reservoir Runoff Coefficient Selection 27 2.2.6 Data Management Tools 32 2.2.7 Data Management Nomenclature 34 2.3 Reservoir Effects Calculation 40 2.3.1 Holdouts 41 2.3.2 Net Evaporation 41 2.3.3 Net Reservoir Effects 42 2.4 Flow Record Filling 42 2.4.1 Statistical Methods 44 2.4.2 Mean Flow Ratio 45 2.4.3 Drainage Area Ratio 46 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc i Table of Contents 2.4.4 Hydrologic Modeling 46 2.5 Local Incremental Flow Computation 47 2.6 Local Incremental Unimpaired Flow Computation 48 2.6.1 Aggregation of Impairments 48 2.6.2 Negative Local Unimpaired Flow Adjustments 48 2.6.3 Selection of Final Local Unimpaired Flow Time Series 49 2.7 Cumulative Unimpaired Flow Computation 50 2.8 Merger of Existing ACT and ACF Incremental Unimpaired Flows 50 2.9 Quality Control of Data 50 3. Apalachicola-Chattahoochee-Flint (ACF) River Basin 54 3.1 ACF Basin Description 54 3.2 Hydrological Data 54 3.2.1 Existing Unimpaired Flows 54 3.2.2 Streamflow Records 56 3.2.3 Reservoir Data 58 3.2.4 Climatological Data 59 3.3 Water Use Data 60 3.4 Reservoir Effects 61 3.4.1 Holdouts 63 3.4.2 Net Evaporation 63 3.4.3 Net Reservoir Effects 66 3.5 Streamflow Filling, Routing, and Reservoir Inflows 67 3.5.1 Methods Summary 67 3.5.2 Buford Dam (BUFORD_R) 68 3.5.3 Columbus (COLUMBUS) 68 3.5.4 Iron City (IRON_CTY) 68 3.5.5 Milford (MILFORD) 69 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc ii Table of Contents 3.5.6 West Point Reservoir (WESTPT_R) 70 3.5.7 Walter F. George Reservoir (WFG_R) 70 3.5.8 Jim Woodruff Reservoir (WOODRF_R) 70 3.6 Local Incremental Flow Calculation and Adjustments 70 3.7 Local Incremental Unimpaired Flow Calculation 72 3.7.1 Negative Local Unimpaired Flow Adjustments 72 3.7.2 Selection of Final Local Unimpaired Flow Time Series 73 3.7.3 Special Cases of Negative Incremental Flows 74 3.8 Merger of Existing and Extended Unimpaired Time Series 75 3.9 Quality Control 78 3.10 Cumulative Unimpaired Flows 78 3.11 Conclusions 78 4. Alabama-Coosa-Tallapoosa (ACT) River Basin 79 4.1 ACT Basin Description 79 4.2 Hydrological Data 80 4.2.1 Existing Unimpaired Flows 80 4.2.2 Streamflow Records 80 4.2.3 Reservoir Data 82 4.2.4 Climatological Data 84 4.3 Water Use Data 86 4.4 Reservoir Effects 87 4.4.1 Net Evaporation 87 4.4.2 Methods Summary 89 4.4.3 Allatoona Reservoir (ALATNA_R) 89 4.4.4 Carters Reregulation and Carters Reservoirs (C_REREG and CARTERS_R) 90 4.4.5 Gaylesville (GAYLES) 90 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc iii Table of Contents 4.4.6 Rome on the Oostanaula River (ROME_O) 91 4.4.7 Rome on the Etowah River (ROME_E) 92 4.4.8 Kingston (KINGSTON) 92 4.5 Local Incremental Flow Calculation and Adjustments 93 4.6 Local Incremental Unimpaired Flow Calculation 95 4.6.1 Negative Local Unimpaired Flow Adjustments 95 4.6.2 Selection of Final Local Unimpaired Flow Time Series 96 4.7 Merger of Existing and Extended Unimpaired Flow Time Series 96 4.8 Quality Control 97 4.9 Cumulative Unimpaired Flows 97 4.10 Conclusions 98 5. Ocmulgee-Oconee-Altamaha (OOA) Study Basin 99 5.1 OOA Basin Description 99 5.2 Hydrological Data 101 5.2.1 Existing Unimpaired Flows 101 5.2.2 Streamflow Records 101 5.2.3 Reservoir Data 101 5.2.4 Climatological Data 103 5.3 Water Use Data 105 5.4 Reservoir Effects 106 5.4.1 Holdouts 106 5.4.2 Net Evaporation 106 5.4.3 Net Reservoir Effects 109 5.4.4 Minimum Reservoir Releases 110 5.5 Streamflow Filling, Routing, and Reservoir Inflows 110 5.5.1 Methods Summary 111 5.5.2 Jackson (JACKSON) 111 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc iv Table of Contents 5.5.3 Penfield (PENFIELD) 112 5.5.4 Vernon (VERNON) 113 5.5.5 Baxley (BAXLEY) 113 5.6 Local Incremental Flow Calculation and Adjustments 114 5.7 Local Incremental Unimpaired Flow Calculation 115 5.7.1 Negative Local Unimpaired Flow Adjustments 116 5.7.2 Selection of Final Local Unimpaired Flow Time Series 116 5.8 Quality Control 117 5.9 Cumulative Unimpaired Flows 118 5.10 Conclusions 118 6. Savannah and Ogeechee (SO) River Basins 119 6.1 SO Basin Description 119 6.2 Hydrological Data 121 6.2.1 Existing Unimpaired Flows 121 6.2.2 Streamflow Records 122 6.3 Water Use Data 124 6.4 Reservoir Effects 126 6.4.1 Reservoir Operational Data 126 6.4.2 Holdouts 126 6.4.3 Net Evaporation 129 6.4.4 Net Reservoir Effects 129 6.5 Streamflow Filling, Routing, and Reservoir Inflows 133 6.5.1 Methods Summary 133 6.5.2 Reservoir Time Series Adjustments 134 6.5.3 Data Time Shifts 137 6.5.4 Russell-Thurmond Pumpback Operation 137 6.5.5 Hartwell Reservoir (HARTWL_R) 137 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc v Table of Contents 6.5.6 Richard B. Russell Reservoir (RBR_R) 140 6.5.7 Thurmond Reservoir (THRMND_R) 142 6.5.8 Burtons Ferry (BURTONS) 143 6.5.9 Kings Ferry (KINGSFY) 145 6.5.10 Augusta and Clyo (AUGUSTA, CLYO) 145 6.5.11 Savannah (SAVANNAH) 145 6.6 Local Incremental Flow Calculation and Adjustments 146 6.6.1 Richard B. Russell Reservoir (RBR_R) 146 6.6.2 Thurmond Reservoir (THRMND_R) 147 6.6.3 Other Nodes 148 6.7 Local Incremental Unimpaired Flow Calculation 149 6.7.1 Special Cases – Reservoir Effects 149 6.7.2 Negative Local Unimpaired Flow Adjustments 149 6.7.3 Selection of Final Local Unimpaired Flow Time Series 150 6.8 Quality Control 151 6.9 Cumulative Unimpaired Flows 152 6.10 Conclusions 152 7. Ochlockonee, Suwannee, Satilla, and St. Mary’s (OSSS) River Basins 153 7.1 OSSS Basin Description 153 7.2 Hydrological Data 153 7.2.1 Streamflow Records 153 7.3 Water Use Data 156 7.4 Streamflow Filling, Routing, and Reservoir Inflows 157 7.4.1 Methods Summary 157 7.4.2 Alapaha (ALAPAHA) 158 7.4.3 Bemiss (BEMISS) 158 7.4.4 Concord (CONCORD) 159 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc vi Table of Contents 7.4.5 Fargo (FARGO) 159 7.4.6 Jennings (JENNINGS) 159 7.4.7 Pinetta (PINETTA) 160 7.4.8 Quincy (QUINCY) 160 7.4.9 Quitman (QUITMAN) 160 7.4.10 Statenville (STATVL) 160 7.4.11 Thomasville (THOMASVL) 161 7.4.12 Offman (OFFMAN) 161 7.4.13 Gross (GROSS) 162 7.5 Local Incremental Flow Calculation and Adjustments 162 7.5.1 Concord (CONCORD) 163 7.5.2 Jennings (JENNINGS) 164 7.5.3 Pinetta (PINETTA) 164 7.5.4 Statenville (STATVL) 164 7.5.5 Final Adjustments to Unimpaired Local Incrementals 165 7.6 Local Incremental Unimpaired Flow Calculation 166 7.6.1 Negative Local Unimpaired Flow Adjustments 166 7.6.2 Selection of Final Local Unimpaired Flow Time Series 167 7.7 Quality Control 167 7.8 Cumulative Unimpaired Flows 168 7.9 Conclusions 168 8. Tennessee (TN) River Basin 169 8.1 TN Basin Description 169 8.2 Hydrological Data 169 8.2.1 Streamflow Records 169 8.3 Reservoir Data 172 8.4 Climatological Data 172 c:\documents and settings\administrator\desktop\surface water availability reports\unimpaired flows data report\uif_rpt_-_final_2010_04_27.doc vii Table of Contents 8.5 Water Use Data 173 8.6 Reservoir Effects 173 8.6.1 Reservoir Holdouts and Inflow Calculations 174 8.6.2 Net Evaporation 174 8.6.3 Net Reservoir Effects 174 8.7 Streamflow Filling, Routing, and Reservoir Inflows 175 8.7.1 Methods Summary 175 8.7.2 England (ENGLAND) 176 8.7.3 Chickamauga (CHICKMGA) 177 8.7.4 Blue Ridge Reservoir (BLRIDG_R) 178 8.7.5 Copperhill (COPRHILL) 179 8.7.6 Nottely Dam (NOTLY_R) 181 8.7.7 Chatuge Dam (CHATUG_R) 181 8.7.8 Little Tennessee (LITLE_TN) 182 8.8 Local Incremental Flow Calculation and Adjustments 182 8.9 Local Incremental Unimpaired Flow Calculation 183 8.9.1 Negative Local Unimpaired Flow Adjustments 183 8.9.2 Selection of Final Local Unimpaired Flow Time Series 184 8.10 Quality Control 185 8.11 Cumulative Unimpaired Flows 185 9.