June 26, 2016--After years of drought and overuse, the San Luis Valley aquifer refills (High Country News)

The San Luis Valley in southern Colorado is an 8,000-square-mile expanse of farmland speckled with potato, alfalfa, barley and quinoa fields between the San Juan and Sangre de Cristo mountain ranges. Only about 7 inches of rain fall each year in the San Luis Valley. But while farmers and ranchers can’t depend on moisture above ground, they make up the difference beneath it. The valley is underlain by a vast aquifer, which is punctured by more than 6,000 wells that pump water onto the valley’s crops and supports the livelihoods of 46,000 residents. For generations, the aquifer provided enough water to sustain the arid farming community. But beginning in 2002, a multi-year drought shrunk the nearby streams and water table. Farmers and ranchers began to notice the falling levels of the Rio Grande and the rapidly draining aquifer. Some wells throughout the valley abruptly stopped working.

The aquifer dwindled so much that the Closed Basin Project, a Bureau of Reclamation pumping effort that had long met downstream water diversions and delivered flows to the Rio Grande River to maintain the Alamosa National Wildlife Refuge, failed to convey enough water to the valley’s farms and ranches. “We operate in a highly over-appropriated system,” says Cleave Simpson, manager of the Rio Grande Water Conservation District, the main water management entity in the San Luis Valley. “Agriculture had overgrown and far outstretched water supply.” Without change, state water regulators could shut off thousands of wells. So the valley’s farmers and ranchers, unlike other agriculture communities in the West, did something nearly unprecedented: They decided not to ignore the problem.

In 2006, the Rio Grande Water Conservation District and San Luis Valley water users created the sub-district project, an innovative solution for solving water problems. The plan would charge farmers and ranchers $75 per acre-foot for the groundwater they pumped, and in turn use the funds to pay farmers to fallow portions of their fields, limiting demand on the water supply, as High County Newsreported in 2013. The experiment began at sub-district 1, the valley’s largest of six sub-districts, which sits at the heart of the San Luis Valley in aptly named Centre, just west of the Great Sand Dunes National Park. Today, four years into the operation of the project after it launched in 2012, the aquifer is rebounding. Water users in sub-district 1 have pumped one-third less water, down to about 200,000 acre feet last year compared to more than 320,000 before the project. Area farmers have fallowed 10,000 acres that once hosted thirsty alfalfa or potato crops. Since a low point in 2013, the aquifer has recovered nearly 250,000 acre-feet of water. By 2021, the sub-district project plans to fallow a total of 40,000 acres, unless the ultimate goal of rebounding the aquifer can be reached through other conservation efforts, like improving soil quality and rotating to more efficient crops. To read the full article visit the High Country News.