More cities are exploring the use of groundwater across the Rio Grande Valley, including Raymondville, Mercedes, and Brownsville.

McAllen just announced their newest groundwater project.

McAllen Utilities Director Mark Vega said the city uses about 28 million gallons per day from the Rio Grande.

The city broke ground on new groundwater test wells that they hope will produce an additional 8 million gallons of water.

“Right now McAllen, as well as 95% of the Rio Grande Valley, depends on the Rio Grande, Vega said. “With the recent droughts that we've had, with Mexico not repaying the water debt, it really puts us in a very precarious position. So we would like to diversify our water portfolio."

Groundwater from the six test wells is salty. It will be treated by reverse osmosis systems, which the city is also buying.

Vega said the brackish groundwater project will be the most expensive in the utility's history, at about $180 million, or $22 million for each million gallons produced.

The North Alamo Water Supply Corporation started using groundwater 25 years ago. Groundwater makes up about a quarter of the water they serve their customers.

“You don't have to come in and build 10 million gallons a day, you can come and build a facility that's only 2 or 3 million gallons or 1 million gallons,” NAWSC General Manager Steven Sanchez said. “But you can prepare it to where you can continue to add onto it."

Sanchez said small cities that want groundwater can keep their costs low by keeping their wells close to their water treatment facilities, which can add to the project costs.

Some cities have access to better groundwater, or wells that are less salty. All that will add to the overall price. 

“We'll have an alternative to draw from as opposed to just the Rio Grande, and that's a big factor,” Vega said. 

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