WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN Texas Natural Resource Conservation Commission Austin, Texas Consultant: R. J. Brandes Company Austin, Texas

REQUIREMENTS FOR GRANTING WATER RIGHTS PERMITS TEXAS WATER CODE §11.134 … (b) The commission shall grant the application only if: (1) the application conforms to the requirements prescribed by this chapter and is accompanied by the prescribed fee; (2) unappropriated water is available in the source of supply; (3) the proposed appropriateion: (A) is intended for a beneficial use; (B) does not impair existing water rights or vested riparian rights; ….

SENATE BILL 1 of the 75th Texas Legislature Article 7, Section 7.01 Requires TNRCC to obtain or develop updated Water Availability Models for: • Six River Basins by December 31, 1999 • All Remaining River Basins by December 31, 2001

GENERAL LOCATION MAP Sulphur River Basin

SENATE BILL 1 of the 75th Texas Legislature Requires TNRCC to provide the following results from the Water Availability Models: 1. For each Water Right, the projected amount of water that would be available during a drought of record and when flows are at 75 and 50 percent of normal 2. For each Regional Water Planning Group, the projected amount of water that would be available if cancellation procedures were instigated by TNRCC 3. In coordination with TPWD, the potential impact of wastewater reuse on existing water rights, instream uses, and freshwater inflows to bays and estuaries.

ACTIVITIES INVOLVED IN WATER AVAILABILITY ANALYSES 1. Compilation and Organization of Data 2. Determination of Naturalized Streamflows (~ 50 Years of Monthly Values at Gage Locations) 3. Characterization of Existing Water Rights 4. Development of Water Availability Model 5. Operation of WAM for Different Scenarios (~ 50-Year Simulation Period) 6. Summary and Presentation of WAM Results

BASIC RESULTS FROM WATER AVAILABILITY ANALYSES 1. For Each Water Right, • Simulated Monthly Diversions • Simulated Monthly Reservoir Storage 2. For Each Model Control Point, • Simulated Monthly Unappropriated Water • Simulated Monthly Actual Streamflows

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN BASIN DESCRIPTION

GENERAL LOCATION MAP Sulphur River Basin

GENERAL FEATURES Sulphur River Basin X A S # U L P H R I V B C a s u n t o w i e m r F d v p k D l M

GENERAL FEATURES Sulphur River Basin • Drainage Area: 3,600 sq. miles at State Line • Humid Subtropical Climate, Rainfall: 40-47 in. • Generally Rural Land Use with Limited Urban • Predominantly Pasture/Cropland in the West • Predominantly, Forest Land in the East • 1990 & 2050 Population: 162,000 & 196,000 • Prolific Water Resources: 2.5 Million Ac-Ft/Yr

HISTORICAL AND PROJECTED WATER USE Sulphur River Basin CATEGORY 1980 1990 2000 (projected) 2050 Municipal 28,063 25,770 29,286 28,621 Manufacturing 45,120 88,281 87,627 93,844 Steam Electric 1,947 1,494 1,500 5,000 Mining 1,328 1,155 1,725 1,202 Irrigation 1,775 2,066 2,044 1,933 Livestock 6,459 9,540 9,934 TOTAL 84,692 128,306 132,116 140,534

MEAN AVERAGE RAINFALL Sulphur River Basin

MEAN ANNUAL RUNOFF Sulphur River Basin

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN WATER RIGHTS AND RETURN FLOWS

EXISTING WATER RIGHTS Sulphur River Basin

DIVERSION RIGHTS BY USE TYPE Sulphur River Basin CATEGORY Municipal Industrial Irrigation Mining Recreation Other TOTAL NUMBER OF RIGHTS 15 9 23 1 - - AUTHORIZED DIVERSIONS acre-feet/year 185,057 165,875 28,005 863 379,800

SPECIAL WATER RIGHTS FEATURES Sulphur River Basin • Multiple Priority Dates for Diversions • Multiple Priority Dates for Storage • Multiple Diversion Points • Multiple Reservoirs & Storage Allocations • Off-Channel Reservoirs • Minimum Instream Flow Requirements • Transbasin Diversions

RETURN FLOW LOCATIONS Sulphur River Basin

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN NATURALIZED STREAMFLOWS

NATURALIZED FLOW METHODOLGY Naturalized Flows represent historical streamflow conditions without the influence of man’s activities related to water rights and water use. NATURALIZED FLOWS = HISTORICAL STREAMFLOWS + HISTORICAL DIVERSIONS - HISTORICAL RETURN FLOWS + HISTORICAL RESERVOIR DEPLETIONS

U.S.G.S. STREAM GAGE LOCATIONS Sulphur River Basin

PERIODS OF RECORD FOR U.S.G.S. STREAM GAGES Sulphur River Basin

DEDUCED HISTORICAL INFLOWS FOR RESERVOIRS BASIC EQUATION INFLOW = MONTHLY CHANGE-IN-STORAGE + GROSS EVAPORATION LOSS - TOTAL RAINFALL ON RESERVOIR + RUNOFF FROM RESERVOIR + DIVERSIONS FROM RESERVOIR + RELEASES FROM RESERVOIR

ANNUAL NATURALIZED AND HISTORICAL GAGED STREAMFLOWS Subwatershed A - Sulphur River Basin

ANNUAL NATURALIZED AND HISTORICAL GAGED STREAMFLOWS Subwatershed E - Sulphur River Basin

NATURALIZED STREAMFLOW STATISTICS BY SUBWATERSHED Sulphur River Basin

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN DATA DEVELOPMENT

OTHER DATA REQUIRED FOR WATER AVAILABILITY ANALYSES Sulphur River Basin • Water Rights Diversion Descriptions • Water Rights Storage Descriptions • Monthly Return Flow Descriptions • Distributed Naturalized Streamflows • Monthly Net Reservoir Evaporation Rates • Reservoir Area-Capacity Relationships

NATURALIZED FLOW DISTRIBUTION Sulphur River Basin

TWDB EVAPORATION/RAINFALL HISTORICAL DATA QUADRANGLES Sulphur River Basin

ANNUAL NET RESERVOIR EVAPORATION RATES Sulphur River Basin

AREA-CAPACITY RELATIONSHIPS FOR WRIGHT PATMAN LAKE Sulphur River Basin

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN WRAP-SIM MODEL DEVELOPMENT

WRAP-SIM WATER AVAILABILITY MODEL Sulphur River Basin • Modified Version of Texas A&M WRAP Model • Developed by Dr. Ralph Wurbs (Texas A&M) • Simulates Unappropriated Water and Actual Streamflows in Response to Diversions and Reservoir Storage • Incorporates Prior Appropriation Doctrine • Tailored to Requirements of Senate Bill 1

SPECIAL FEATURES OF WRAP-SIM WATER AVAILABILITY MODEL Sulphur River Basin • Distributes Gaged Naturalized Streamflows • Simulates Off-Channel Reservoir Operations • Provides for Minimum Instream Flows • Accounts for Streamflow Channel Losses • Allows Specification of External Gains/Losses • Allows Monthly-Varying Conservation Storage

WRAP-SIM LINK-NODE NETWORK Sulphur River Basin

SPECIFIC OUTPUT FROM WRAP-SIM WATER AVAILABILITY MODEL Sulphur River Basin 1. For Each Water Right for 1940-1996 Period, • Simulated Monthly Diversions • Simulated Monthly Reservoir Storage 2. For Each Control Point for 1940-1996 Period, • Simulated Monthly Unappropriated Water • Simulated Monthly Actual Streamflows

SPECIAL ASSUMPTIONS MADE FOR WATER AVAILABILITY ANALYSES Sulphur River Basin • Wastewater Reuse Consistent with Reported Return Flows during Last Five Years • Continuous Return Flows from Municipal Discharges During Shortage Periods • Continuous Return Flows from Discharges Based on Groundwater and Import Sources • Simplified Representation of Off-channel Reservoirs

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN WRAP-SIM MODEL OPERATION

RUNS MADE WITH WRAP-SIM WATER AVAILABILITY MODEL Sulphur River Basin In Response to Requirements of Senate Bill 1, • REUSE RUNS • CANCELLATION RUNS • CURRENT CONDITION RUNS

SPECIFICATIONS FOR RUNS MADE WITH WRAP-SIM MODEL Sulphur River Basin

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN WRAP-SIM MODEL RESULTS

DIVERSIONS FOR JIM CHAPMAN LAKE Sulphur River Basin

DIVERSIONS FOR DUNHAM NO. 4148B Sulphur River Basin

STORAGE FOR JIM CHAPMAN LAKE Sulphur River Basin

UNAPPROPRIATED FLOWS AT D/S END OF SUBWATERSHED F Sulphur River Basin

UNAPPROPRIATED FLOWS D/S OF SUBWATERSHED C Sulphur River Basin

UNAPPROPRIATED FLOWS D/S OF SUBWATERSHED F Sulphur River Basin

UNAPPROPRIATED FLOWS D/S OF SUBWATERSHED C Sulphur River Basin

UNAPPROPRIATED FLOWS D/S OF SUBWATERSHED F Sulphur River Basin

UNAPPROPRIATED FLOWS D/S END OF SUBWATERSHED C Sulphur River Basin

RELIABILITY OF WATER AVAILABILITY FOR WATER RIGHTS DIVERSIONS Sulphur River Basin RUN DESCRIPTION PERCENT RELIABILITY By Month By Volume RUN 1 - Baseline, No Reuse 86.0 98.5 RUN 2 - Baseline, 50% Reuse 85.8 98.4 RUN 3 - Baseline, Full Reuse 85.8 98.4 RUN 4 - Baseline, Cancel, No Reuse 84.5 98.9 RUN 5 - 10-Yr Max. Use, No Reuse 90.0 97.9 RUN 6 - Baseline, Cancel, Full Reuse 84.8 98.9 RUN 7 - 10-Yr Max. Use, Full Reuse 89.9 97.9 RUN 8 - 10-Yr Max. Use, Current 89.2 98.0

POTENTIAL IMPROVEMENTS IN WATER AVAILABILITY MODEL Sulphur River Basin • Improved Accuracy of Naturalized Streamflows • Improved Accuracy of Small Drainage Areas • Improved Accuracy of Off-Channel Reservoir Representations • Improved Accuracy of Multiple-Diversion Point Representations

REMAINING TASKS FOR WATER AVAILABILITY ANALYSES Sulphur River Basin • Make WRAP-SIM Program Enhancements • Improve Water Rights Representations in WRAP-SIM Model • Review and Revise Final WAM Report • Prepare Water Availability Charts for Individual Water Rights

WATER AVAILABILITY MODELING for the SULPHUR RIVER BASIN Texas Natural Resource Conservation Commission Austin, Texas Consultant: R. J. Brandes Company Austin, Texas