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. Austin Water is currently studying aquifers in our region to determine the most favorable areas for an Aquifer Storage and Recovery project in the future.
HOW ASR SYSTEMS WORK
When water supplies are plentiful, an Aquifer Storage and Recovery system will store available drinking water from Austin Water in a natural aquifer underground. When our regular water supply becomes low, stored water is pumped out of the aquifer, treated to meet drinking water standards, and distributed to customers. Water collected and stored in an ASR system would be available under Austin’s existing water rights, allowing Austin to maximize local water resources.
From 2008-2016, a historic drought hit Central Texas, reducing water in the Highland Lakes to historically low levels. In response, Austin Water created Water Forward, an integrated plan to guide Austin’s water future for the next 100 years. The City Council-approved Water Forward plan includes conservation, reuse, and water supply strategies to ensure a diversified, sustainable, and resilient water future for Austin. Aquifer Storage and Recovery is one of the water supply projects included in Water Forward. An ASR project will make Austin’s water supply more resilient to the effects of climate change and drought and could provide a second source of water during emergencies, like freeze events or flooding.
EQUITY AND AFFORDABILITY
Austin Water is committed to using an equity and affordability lens to implement this project. The first phase of the ASR project includes development of an equity and affordability road map and tool.
The project team is available to make presentations to community and professional groups. Please follow this link to request a presentation.
Frequently Asked Questions
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 Highland Lakes. An ASR project for flood mitigation is not feasible due to infrastructure and storage requirements as well as cost.
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.
No, the intent of Austin’s ASR project is not to take native groundwater but to 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 TCEQ ASR requirements.
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.
A review of all significant aquifers in Travis and the surrounding counties was performed to investigate characteristics beneficial for ASR projects. Some of those characteristics included: storage capability, potential well capacity, and groundwater regulations. Based on the characteristics, the Trinity and Carrizo-Wilcox aquifers in Bastrop, Lee, and Travis counties have the best potential for Austin’s ASR project.
For more information relating to aquifers and groundwater please refer to the following link, https://www.twdb.texas.gov/groundwater/index.asp
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.
In the next stage of ASR development, we will do more detailed water quality testing through an ASR pilot project. This will let us characterize how the source water stored in the ASR will interact with native groundwater. Extensive water quality testing will be done to ensure compatibility.
Since we have not yet identified specific locations for ASR wellfield areas, we do not have data at this point on potential effects on adjacent wells. 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. This is an important issue and is something we will be considering as we move forward.
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.
2020-2023: Identify where to pilot
2024-2027: Design, construct, and test pilot; develop recommendations for full-scale ASR
2028-2029: Preliminary Engineering for full-scale ASR
2029-2030: Design for full-scale ASR
2031-2035: Construction of full-scale ASR
Water Forward Integrated Water Resource Plan
Feb. 11, 2022 Presentation to Water Forward Task Force
Texas Water Development Board ASR Resources