Aquifer Storage and Recovery
Aquifer Storage and Recovery
Aquifer Storage and Recovery (ASR) is a water supply strategy to store available water in a natural aquifer during wet times for later recovery and use. After extensive research in multiple counties, a portion of the Carrizo-Wilcox aquifer in Bastrop County was identified as the best suited to test for an aquifer storage and recovery project.
Partnership Approach
Austin Water is working with stakeholders in Bastrop County to develop protections and benefits for the Bastrop County community through this project. We want to hear from Bastrop County residents to help us find the best solutions, together.
While the challenges in our communities may differ, we are all connected by our most precious resource, water. Austin wants to work together with our Bastrop County neighbors as we all plan for Central Texas’ future water needs.
Austin Water and Bastrop County stakeholders have drafted a binding agreement that reflects protections, benefits and safeguards for the project. The agreement will be considered for approval in October and November 2025. A draft of the agreement is available for review.
What's Next
Our ask right now is simple: Allow us three years to study water compatibility and show that we’re good neighbors you can trust.
In this phase, groundwater samples and core samples will be tested in a lab to understand baseline geochemistry and will be tested with Austin Water drinking water to observe and document any interactions. Based on these results, appropriate treatment processes can be designed for the next project phase (a small scale pilot) to prevent adverse reactions and protect the health of the aquifer.
During the field-testing phase Austin Water will:
Include input from the ASR Technical Advisory Group about testing methods and criteria.
Share test results with the ASR Technical Advisory Group, Bastrop County stakeholders, and the public.
Continue to engage in a collaborative process.
Bastrop stakeholders will have a voice in the decision-making process.
After receiving test results, the ASR Technial Advisory Group, Bastrop County stakeholders, and Austin Water will make a recommendation about whether the project should continue to the next phase.
Austin Water wants to work with stakeholders to develop a project that can also provide regional benefits. As Central Texas continues to experience rapid population growth and increasing water demands, innovative strategies like ASR will be critical to securing the state’s water future.
Let's Talk Water
Austin Water will hold open house meetings and office hours during Sept. 2025. Please join us to make your voice heard and learn more.
Tell us more about what is important to you – complete this questionnaire.
The project team is available to make presentations to community and professional groups. Please send an email to aw-asr@austintexas.gov to request a presentation.
Frequently Asked Questions
Austin has completed a comprehensive evaluation of numerous aquifers within the region, across eight counties. The Carrizo-Wilcox, which is successfully used for ASR in Bexar County, was determined to be able to meet project goals and provide the storage capacity scale that Austin Water needs.
After careful scientific study, a portion of the Carrizo-Wilcox Aquifer in Bastrop County was identified as the focus area because it has favorable hydrogeology, is closer to the existing system infrastructure, and is in an area where water can be stored deep in the aquifer well and below levels of local wells. An area in Bastrop County several miles south of Paige, TX is the current focus area for the next phase of field testing.
Travis County was thoroughly evaluated but was not identified as the focus area because the hydrogeology is less favorable than Bastrop County, resulting in lower water storage capacity.
For more information relating to aquifers and groundwater please refer to the following link, https://www.twdb.texas.gov/groundwater/index.asp
No, Austin’s ASR project will not take native groundwater. The project will store Austin’s existing water supplies for later use. Austin’s ASR project will not take out more volume of water than it puts into the aquifer, per state ASR requirements from the Texas Commission on Environmental Quality.
In the next stages of ASR development, Austin Water will perform field testing to gather core samples and native groundwater samples and test those in a laboratory setting to understand baseline geochemistry and compatibility with Austin Water drinking water. This will allow design of appropriate treatment processes to prevent adverse water quality reactions and protect the health of the aquifer. After this step, Austin Water will develop a small-scale ASR pilot project to further characterize how Austin’s drinking water that will be stored in the ASR may interact with native groundwater. Extensive water quality testing will be done before a decision is made to move to each subsequent phase of the project.
Austin’s ASR project is planned to store water from Austin’s drinking water system. Water for ASR will be treated before it goes in the ground to ensure compatibility with the aquifer and existing groundwater. When ASR water is recovered, it will be treated to be fully compatible with AW’s existing drinking water quality.
The amount of land needed for an ASR project is based on location and aquifer characteristics. We currently estimate that up to approximately 7,000 acres will be needed for the wellfield and a half mile buffer. Only about 200 acres of that amount will be needed for wells, facilities, and aboveground improvements.
To legally protect the stored water, the land above the storage zone must be protected from pumping. Landowners will be compensated for purchase or lease of land and may remain on the land to continue local farming and ranching operations.
Austin Water will seek to operate the ASR wells in a manner that minimizes local well impacts. We understand from other ASR projects that overall water levels for adjacent wells typically increase when water is being added to the ASR and decrease when ASR water is being withdrawn. Austin’s ASR project will not withdraw (or recover) more water than was stored. Austin Water will improve and lower wells where necessary.
Austin Water’s 2024 Water Forward plan has a goal of storing 60,000 acre feet of water in the planned ASR project by 2040 and 300,000 acre feet by 2080.
No, Austin’s ASR project is not planned to capture flood waters. The ASR project will store drinking water from Austin's core supply source, the Colorado River and Highland Lakes. An ASR project for flood mitigation is not feasible due to infrastructure and storage requirements as well as cost.
Austin Water will pay for this project over a number of years using strategies that allow us to finance large projects while keeping customer rates affordable. Austin Water’s debt management strategies have made it possible to address two competing needs – spending on improvements infrastructure for dependable water service while keeping water rates down and affordable for customers of all incomes. Securing near-zero percent interest loans also helps Austin Water fund major infrastructure projects at a tremendous cost savings for the utility and its customers.
It is a priority for Austin Water to choose a location for the project that will allow us to protect the water that we store. AW will have control of the land above our stored water, but due to the early stage of the project, we have not yet identified specific strategies to achieve that. Other ASR projects, for example, have purchased the land above their stored water to protect it, and leased the land back to farmers or ranchers. Additionally, Texas Commission on Environmental Quality (TCEQ) requirements for ASR state that ASR projects must be able to maintain control over their stored water.
The ASR team will hold community meetings to share information and collect input on the ASR project and will attend meetings in the community throughout the project. Community engagement events will be conducted in the summer of 2022 to receive input on the criteria and weightings that will be used by the project team to evaluate different project alternatives.
We are also developing an Equity and Affordability Road Map and Tool to help implement the ASR project with an equity and affordability lens. These products will help guide our community engagement efforts along with determining potential equity impacts and mitigation options when evaluating ASR project configurations.
Let's Talk Water
Take a few minutes to give us your input in this short questionnaire.
Please join us at an upcoming Open House or Office Hours session. We are here to listen, share information, and work beside you to protect what matters.
Bastrop Open House
Bastrop Office Hours
Paige Open House
Paige Open House
Smithville Open House
Giddings Office Hours
Drop-in and talk one-on-one
Smithville Office Hours
*Results of each project phase will be evaluated to determine whether the project will move to the next phase.