1. An Interregional Water Solution with Conjunctive Use of Groundwater Haskell L. Simon President, Coastal Plains Groundwater Conservation District Vice President, Region K Water Planning Group

2. New Era for Water Planning Based on “Bottom Up” or “Grass Roots” Approach Address anticipated water shortages over a 50 year period by determining: Available water supplies Demands for water Strategies to achieve projected short falls SB1 (1997) Mandate for Statewide Water Plan

3. The Essence of the SB1 Process Top Down Approach vs. Bottom Up Approach Before Today

4. 16 Regions in Texas Each group represented by one or more individuals from 11 “Interest Groups” RWPG is responsible for preparing and adopting a regional water plan Regional Plans consolidated into the State Water Plan “Water for Texas 2002” Implementation of the Plan will require legislative and/or regulatory action. SB1 Regional Approach

5. Regional Water Planning Areas

6. Regional Planning Group Membership (11 Interest Groups) 1. Public 2. Counties 3. Municipalities 4. Agricultural Interests 5. Environmental Interests 6. Industries 7. Small businesses 8. River Authorities 9. Water Districts 10. Water Utilities 11. Electrical Generating Utilities

7. Year Million Acre-feet Projected Urban & Agricultural Water Uses

8. Total Water Demand by Type of Use (2003) Year 2000 Year 2060

9. Use by Source of Supply (2000) SURFACE WATER 65% GROUND- WATER 35%

10. 2050 Water Needs SB 1 Planning Process (entire state & border regions) Region K 2050 Shortfalls 160,000 acre-feet/yr of irrigation Some rural communities upstream of Highland Lakes (5,400 acre-feet/yr)

11. 2050 Water Needs SB 1 Planning Process (entire state & border regions) Region L Bexar County shortfall 350,000 acre-feet/yr of municipal use (current update to plan will reduce this amount)

12. Regional Cooperation Defines Project SB 1 Planning Process (entire state & border regions) Region K (LCRA) Region L (SAWS) LCRA- SAWS Water Project

13. Regional sharing of resources to meet future water needs The LCRA-SAWS Water Project is designed to meet the needs of both the lower Colorado River basin and the San Antonio area The lower Colorado River basin needs additional water to satisfy agricultural needs, protect Highland Lake levels and provide water for upstream rural communities San Antonio needs significant additional water to meet growth and economic development needs

14. Project Summary Construct off-channel reservoirs to store surface waters Institute practices and improvements to reduce agriculture’s demand for water Install groundwater wells to serve agriculture’s needs during drought Create up to 150,000 acre-feet per year for SAWS Meet environmental requirements Study Period activities determine implementability and permitting

15. LCRA-SAWS Water Project More stable water levels in Highland Lakes Water for agriculture Water for rural communities Austin San Antonio Lake Buchanan Freshwater inflows for Matagorda Bay Instream flows to maintain aquatic habitat Water for San Antonio (up to 150,000 ac-ft/yr)

16. LCRA SAWS Water Project Develop 330,000 ac-ft of water by: 1. Irrigation conservation - Onsite and system improvements in districts P P 3. Conjunctive use of groundwater for agricultural needs during drought Matagorda Bay Bay City Wharton Columbus Colorado Wharton Matagorda 2. Off-channel reservoirs

17. Legislation requires that in order for the project to proceed, the project must... 1. Protect and benefit basin interests 2. Be consistent with the state regional water plan 3. Provide inflows adequate to maintain the ecological health and productivity of Matagorda Bay 4. Maintain current instream river flow protections 5. Ensure that San Antonio practices stringent conservation measures 6. Provide for a broad public and scientific review process 7. Benefit stored water levels in Lakes Travis and Buchanan

18. We are at the beginning of a multi- year, comprehensive evaluation 2002 2007-2008 20102004 Technical Study Plan Development Technical Studies Permit Submittal & Continuation of Studies Permitting Review & Completion of Studies

19. Groundwater Average of 62,000 ac- ft per year in severe droughts Divert only to Colorado basin agricultural users Groundwater used only in times of drought

20. Groundwater Modeling Overview Simulate a range of withdrawals to meet agricultural needs during drought Evaluate impacts to groundwater/ surface water Assess impacts of pumping on groundwater quality Assess uncertainty with model predictions

21. Groundwater Study Objectives Potential mitigation techniques for users, if affected Saline water encroachment from the coast. Land surface subsidence Induced migration of poor quality native groundwater that could result from increased groundwater use Determine if additional groundwater can be developed without substantially affecting the current groundwater users and evaluate:

22. Comprehensive Groundwater Evaluation Defines consequences of conjunctive use Identifies mitigation needs and options Uses more data and performs more data analyses than the GAM Predictions will contain confidence limits based on uncertainty associated in calibrated model Model will be developed at the spatial resolution supported by the data 0.1 to 0.5 mile variable grid anticipated

23. Stay tuned...