Walking on water? Austin taking steps to store surplus underground for future drought
With Austin weathering one of its worst droughts in at least a decade, as the effects of climate change become more apparent, the city hopes to store a few months' worth of drinking water underground to prepare for even worse dry spells.
The public will have one last scheduled chance on Thursday to weigh in on how the city should choose where it will store Austin's surplus water.
More on climate change:5 ways you can help tackle climate change in Austin right now
Helen Gerlach, project manager for the water supply strategy called aquifer storage and recovery, or ASR, said Tuesday that Austin has a choice among three aquifers, which are natural layers of rock or sediment below the ground that can hold large amounts of water, in Travis, Lee and Bastrop counties. The aquifers by 2040 would store about 60,000 acre-feet of water. For context, the entire city used nearly three times that amount of water last year.
An acre-foot is the amount of water it takes to cover an acre in water a foot deep.
The larger plan is to have 240,000 acre-feet of water, or more than a year's supply, stored by the year 2115. A baby born this year would be 93 by the time the aquifer reaches that level.
"Aquifer storage and recovery is a key part of the plan to help mitigate the effects of climate change because it provides additional storage that we could access during a drought," Gerlach said. "By storing the water underground, you're not losing water due to evaporation."
Austin's fall fire risk:'Heat-driven fires to wind-driven fires': Here's how wildfire risk is changing for Austin
Why does Austin need an aquifer?
Austin residents can think of aquifer storage and recovery like a savings account, with city leaders pulling from its normal drinking water supply during rainy years and storing away extra to be used during drought or emergencies.
An eight-year drought, spanning from 2008 to 2016, drained water levels at the Highland Lakes — a chain of lakes along the Colorado River from Lake Buchanan to Lake Austin — to historic lows. The lakes are a water source for Austin, so fears of them running dry prompted the city to create its Water Forward Plan.
The Water Forward Plan focuses on strategies to ensure Austin will have drinkable water as climate change progresses over the next 100 years, with ASR being one of its largest drought-focused projects.
Air Quality: Austin had more Ozone Action Days this year than in 8 years combined. Here's why that could change
It's predicted that Austin in the next 50 years could see temperatures rise from a summer average high of 96.9, to summer average highs of between 97.9 and 100.2, according to a 2014 study of Austin conducted by ATMOS Research and Consulting. Toward the end of the century, the range of averages could rise even higher, between 98.6 degrees to 103.8, the study said.
Hotter temperatures mean the likelihood of even more extreme drought, but climate experts also are banking on potentially longer periods of heavy rainfall that could provide enough water to help the city through its dry spells.
San Antonio, El Paso and Kerrville have all successfully used aquifers for their not-so-rainy days, so Austin is able to take notes on their success when creating its own plan.
Want to go electric?Affordability still a roadblock to buying an electric car? Here's why it's getting better
What's next?
The next step in the project is choosing among the aquifers in Travis, Lee and Bastrop counties, so Austin has created a set of criteria to help pick the best one.
The public, in a virtual meeting 6 p.m. Thursday, will have a chance to review the criteria — ranging from overall cost, the potential to expand storage and accessibility — and share their thoughts. Residents will also be able to comment on how the plan will address equity and affordability concerns, specifically how it will affect nearby communities.
Austin Water right now is working to make the project more affordable through low-interest state loans, but the utility is still planning to pay for the project through rates paid by customers.
More on Climate Change:How planting fruit trees could help cool down Austin's heat island amid climate change
"We're interested in hearing any feedback people want to provide," Gerlach said. "We're specifically presenting on the evaluation criteria we will be using to help select an ASR location. We've got the technical evaluation criteria, as well as an equity and affordability framework that we're using to evaluate possible locations."
Gerlach continued that she's "hoping to get feedback from folks on changes we could make or things that we could include" to choose the best aquifer.
Once a location is chosen, Austin plans to begin field testing at the site in 2024 to make sure the aquifer is what they expected. After that, the city would build a small pilot program starting in 2025 that would operate for one or two years.
It could take up to seven more years for the final design and construction of the full-scale system to be complete, meaning that residents might have to wait until the mid-2030s for the project to be fully operational.
"We're undertaking the project now because it's important to give ourselves lots of lead time for community engagement, piloting, construction and storing water to meet our 2040 goals," the city said in a statement.
Residents can register for the virtual meeting using the Zoom link at austintexas.gov/news/austin-water-seeks-community-feedback-aquifer-storage-and-recovery-project. They can also provide input online at https://austinasrinput.com/.
Water Quality:Austin Water to test for human-made chemicals linked to cancer, fertility issues
This article originally appeared on Austin American-Statesman: Walking on water? Austin taking steps to store surplus underground
