Groundwater is a proven crutch for dry times, but how much weight can it hold?

Photo © Brett Walton / Circle of Blue Colorado’s San Luis Valley is pinched by two mountain ranges, the San Juan peaks to the west and the Sangre de Cristo, seen here, to the east. The Rio Grande flows through the Valley before entering New Mexico.

A few weeks ago, I wrote about how groundwater withdrawals have rescued farmers in southern New Mexico from scant surface water from the Rio Grande. Thanks to consecutive subpar snow seasons in the Rockies, the eponymous reservoir that serves Elephant Butte Irrigation District is more than 80 percent empty.

Farmers responded in 2011 by pumping a record amount of groundwater. They are likely to do so again this year. And that has caught the attention of municipal officials in nearby Las Cruces, which uses the same aquifers to supply its population of nearly 100,000.

Asked by the Las Cruces Sun-News if he was concerned about the increase in groundwater use, city councilman Greg Smith said, “Absolutely.” He went on to say that there could be more cooperation between large-scale irrigators, small-scale farmers, and the city.

Not Just New Mexico

The Texas Tribune reports that 50 miles downstream, near El Paso, the Rio Grande has run dry for the first time in a decade. The largest city in western Texas (pop. 650,000) will pump more groundwater and fire up the world’s largest inland desalination plant to cover the shortfall. In many places, aquifers have long been the easy emergency water source: drill a well and pump. But groundwater tables, including in the Texas Panhandle, are falling. Combine the ease of access with declining surface runoff, climate change, and growing demand, and you have a recipe for disaster.

Few States Rewriting Groundwater Management

This legislative session, for example, Kansas Governor Sam Brownback signed five water conservation bills, several of which provide longer planning horizons for groundwater use. But in Texas, the state Supreme Court ruled this winter in favor of landowners’ rights when it comes to groundwater pumping. The implications of the ruling, especially for conservation and groundwater regulation, are still to be determined.

Have a groundwater story to share? Contact Brett Walton

–Brett Walton

Circle of Blue reporter