June 2, Calvin Finch Ph.D. Texas A&M Water Conservation & Technology Center

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1 Expanding the Role of SAWS Twin Oaks ASR To Become the Primary Endangered Species Protection Activity at San Marcos and Comal Springs and the Texas A&M Aquifer Storage and Recovery Initiative. June 2, 2014 Calvin Finch Ph.D. Texas A&M Water Conservation & Technology Center 1

2 SAWS Twin Oaks ASR as the Primary Endangered Species Protective Activity and the Texas A&M ASR Initiative Edwards Aquifer as Water Source SAWS ASR Edwards Aquifer Habitat Conservation Plan Local and Regional Role for ASR Texas A&M ASR Initiative 2

3 Edwards Aquifer 3

4 Edwards Aquifer Karst (limestone aquifer) Fills up fast and levels fall fast based on use and rain Users include agriculture, San Antonio, small cities Comal and San Marcos Springs are dependent on aquifer levels endangered species, recreation, environmental flows, downstream water 4

5 Characteristics of Edwards Aquifer Edwards Aquifer can be managed based on recharge in long term; short term management is tougher. Pumping limits, drought restrictions, protection of recharge zone 5

6 Edwards Aquifer as Water Source Regulated Edwards Aquifer Authority, EAA Permit Limit 572,000 acre feet Active Water Market Drought Restrictions Reduce Availability by up to 44% Habitat Conservation Plan Stabilize Water Availability and Protect Species 6

7 Endangered Species 7

8 Endangered Species 8

9 History of the Edwards Issue In 1991, the Sierra Club filed a lawsuit to ensure the long term protection and survival of the federally protected endangered species Basic case: Unregulated usage of the Edwards Aquifer threatened minimum continuous springflows and jeopardized the continued existence of these species in the wild In 1993, Honorable Judge L. Bunton issued his ruling 9

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11 EARIP Basics 101: Review Edwards Aquifer Recovery Implementation Program (EARIP) Balances the recovery of listed species with water use and development through a multistakeholder process Informally convened: Early 2007 Formally Legislated: May 2007 (Senate Bill 3) Comal Springs run & aquatic vegetation June

12 Motivation for Bottom s Up Management In addition to lawsuits and threat of Federal Intervention. Using strictly pumping restrictions would require 85% cutbacks! Cost of large engineered solutions (quarries, new ASRS, off channel reservoirs) $400 million $1.7 billion capital costs $40 million $90 million O&M 12

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14 Motivation for including SAWS ASR as part of Management Plan Local operation indicated it had more capacity than originally planned Save SAWS and the Region large sum of money and access to Edward s water Modeling indicated the lease, fill, pump back, and reduce aquifer pumping had major impact on aquifer levels and spring flow Modeling indicated that both the local and Regional (HCP) goals could be accomplished with skillful management 14

15 Phase 1 Program and Reduced SAWS Pumping 15

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17 Local VS Regional Water 1) SAWS uses ASR water to keep out of advanced drought restrictions 2) SAWS is able to stabilize aquifer level during summer (after main agriculture irrigation ends) with restrictions and ASR use 3) Regional filling requirements reduce flexibility 17

18 Local VS Regional Water 1) Potential conflict is reduced if ASR is full, 120, ,000 acre ft 2) SAWS makes decisions about filling and use within certain parameters and with help of Regional committee. 3) SAWS plan to build second distribution pipeline west side of City will increase flexibility 18

19 Goals for Local and Regional Use of ASR 1) Region leases 50,000 acre ft of water in 3 categories based on depth of Drought of Record. Category 1 seeks to provide 16,667 acre ft per year until at least 40,000 acre ft in storage. 2) Drought of Record officially in place if 10 year rolling recharge amount falls to 500,000 acre ft. Return of maximum amount possible is required at that point. 3) SAWS only responsible for 126,000 acre ft over the 10 years of the Drought of Record and for a maximum of 46,300 acre ft in worst year. 19

20 Crediting Options Experience in 2014 and realization that it will be politically difficult to stop local deliveries of water to San Antonio while Regional Water was being stored led to Credit Option also called forbearance. SAWS can choose to credit existing water in the ASR to the Regional Account at its discretion to make it unnecessary to stop local recovery. In the end SAWS just reduces its pumping from the Edwards Aquifer even if Regional water cant be injected. 20

21 Goals for Local and Regional Use of ASR The results expected in this expansion of the use of the SAWS Twin Oaks ASR to meet Regional HCP goals reveals the potential value of the technology to water reserve inventories and planning. 21

22 Texas A&M Aquifer Storage and Recovery Initiative Funded as seed money by Texas A&M Engineering Experiment Station (TEES) with funds from Texas Legislative Exceptional Item for Water Conservation towards end of developing Texas A&M, San Antonio as a center of ASR research, expertise and education. 22

23 TAMU ASR Initiative Centered at new campus at San Antonio but includes team members from College Station and Corpus Christi in addition to San Antonio Civil Engineer, Mechanical Engineer, Microbiologist, Groundwater Modeler, Water Conservation Educator and Graduate Students. Research, Feasibility and Outreach 23

24 Texas A&M ASR Initiative Research Create a reactive transport modeling framework to represent biogeochemical processes specifically affecting ASR Determine chemical changes of injected and recovery waters due to contact with geologic formations and mixing Test framework based on existing data from Twin Oaks ASR facility 24

25 Texas A&M ASR Initiative Feasibility Assess the prospects for using ASR in 3 major Texas Aquifers Trinity, High Plains and Gulf Coast Extension and Outreach Create ASR website, speakers bureau; handouts, and short courses targeted at specific audience 25

26 Contact Information ASR Team Lead Calvin Finch, Ph.D. (210) x240 Principal Investigator ASR Initiative Gretchen R. Miller, Ph.D., P.E. (979)