In a stab at broadening water supplies in an increasingly crowded region, a groundwater district that straddles Travis and Hays counties is raising money to study building a desalination plant.
The Barton Springs/Edwards Aquifer Conservation District is asking the state for $275,000 to study the feasibility of a facility that could pump and clean brackish groundwater.
Desalination plants, once the province of science fiction, have become increasingly popular as the water in rivers, lakes and other sources is spoken for or politically difficult to secure.
There are at least 30 such plants across the state, with the largest, El Paso’s Kay Bailey Hutchison Desalination Plant, capable of cleaning 27.5 million gallons a day.
San Antonio is building a facility of its own that could be up and running by late 2016.
But Central Texas, flush with the Colorado River and the Edwards Aquifer, has long sidestepped the need to invest in major desalination facilities, which generally cost more than existing surface and groundwater sources.
That may be changing, as communities forecasting heavy population increases cast about for ways to meet the washing, bathing, drinking and lawn-watering needs of residents and businesses.
“Conventional water supplies are exhausted already,” said groundwater district general manager John Dupnik.
The state’s South Central Texas regional water plan foresees at least three brackish groundwater desalination projects atop area aquifers by 2060, at a cost of $378 million, providing up to 42,220 acre-feet, or 13.8 billion gallons, of water a year.
An acre-foot of water is about what four average Austin homes use in a year.
The groundwater district, which serves at least 60,000 people, has asked the Texas Water Development Board for money to help pay an engineering firm to drill and analyze the results from a test well east of Interstate 35, which will likely be at least 800 feet deep, said Brian Smith, a hydrogeologist with the district.
This week the district, which will contribute $285,000 in salary time and equipment, is seeking letters of support from Travis County and Hays County for the feasibility project. The district also will examine whether the saline portion of the aquifer can be used as a kind of natural underground reservoir — another strategy being employed in other parts of the state.
The Austin-based Lower Colorado River Authority has estimated that it could cost at least $1,000 per acre-foot to turn brackish groundwater into usable water. On the other hand, squeezing more out of current water resources — through conservation — costs $250 to $450 per acre-foot.
Local and state officials have examined the possibility of Austin-area desalination before.
In 2012 the state General Land Office looked at building a desalination plant between Austin and New Braunfels on state land.
The project was deemed uneconomical, said Land Office spokesman Jim Suydam.