Mitigating Drought Impacts on Estuary Inflows using Aquifer Storage and Recovery

Tuesday, February 27, 2018: 1:40 p.m.
James Dodson , GroundswellTX - Water & Coastal Resources Consulting, Victoria, TX
R. David G. Pyne, M.S.E. , ASR Systems LLC, Gainesville, FL
Joseph Trungale, M.S. , Trungale Engineering and Science, Austin, TX

Surface water in Texas is regulated under prior appropriation statutes recently amended to include provisions designed to protect instream flows and estuary inflows, but these provisions only apply to new or amended water rights. However, most river basins are already fully appropriated, leaving little real opportunity to utilize these new rules to achieve the instream flow and estuary inflow protection targets recently established through a process involving “Basin and Bay Area Stakeholder Committees (BBASC)” and expert science teams. The State of Texas continues to fund BBASCs to study adaptive management strategies designed to achieve the State’s goal of providing a “sound ecological environment” for Texas’ rivers and estuaries.

One adaptive management study recently commissioned by the Guadalupe-San Antonio (GSA)-BBASC investigated the use of two untapped categories of surface water flows – treated wastewater return flows and unappropriated water rights – and Aquifer Storage and Recovery (ASR) as a means of achieving the “Strategy Target Frequencies (STFs)” for the spring and summer freshwater inflow targets the GSA-BBASC established for the San Antonio Bay - Guadalupe Estuary System during drought periods.

A water availability model was used to calculate how much water from these two categories would be available for ASR storage during the “good years,” the total volume of ASR storage needed to meet the STFs for estuary inflows through a drought of record, and the volume of ASR recovery capacity required to deliver the stored water to the estuary during the spring and summer target periods. Modeling results were used to size ASR facilities to meet the STFs, and to prepare conceptual designs and cost estimates for a series of ASR facilities located along the lower Guadalupe River, just above the estuary. The project report included recommendations for state water policy changes needed to facilitate this innovative strategy.

James Dodson, GroundswellTX - Water & Coastal Resources Consulting, Victoria, TX
Mr. Dodson has worked on water supply and environmental flow protection issues involving river basins and estuaries in South Central Texas for over 25 years. His recent focus has been on investigating and developing conjunctive use projects which provide both municipal/industrial water supply and protect/enhance flows in rivers and freshwater inflows to estuaries along the Middle Texas Coast. Since it was formed in 2010, he has served as Program Facilitator for the San Antonio Bay Partnership, a nonprofit working to "protect, restore and enhance the natural resources and human uses of the San Antonio Bay - Guadalupe Estuary System."



R. David G. Pyne, M.S.E., ASR Systems LLC, Gainesville, FL
Mr. Pyne has worked as a professional engineer in the water supply, wastewater and water resouces fields, pioneering the development and implementation of Aquifer Storage Recovery (ASR) technologies, both in the U.S. and worldwide. He is the author of “Aquifer Storage Recovery: A Guide to Groundwater Recharge through Wells” – which, now in its second edition (2005), shares the knowledge he has amassed in his 35 years of groundbreaking work in the assessment, design, and development of ASR projects.


Joseph Trungale, M.S., Trungale Engineering and Science, Austin, TX
Mr. Trungale is an independent consultant with expertise in instream flow studies to quantify the effects of changing flow regimes on aquatic habitat. His expertise extends to groundwater-springflow studies, freshwater inflows for bays and estuaries, and regional/state water planning including water availability analysis and water rights review. Mr. Trungale brings his expertise in engineering and ecological science to the public policy and legal arenas. He works with diverse groups of stakeholders and scientists to develop innovative solutions to natural resource challenges that balance growing human needs for water with the need to protect and maintain sound ecological environments.