Years of lower-than-average precipitation have forced the issue of irrigation water to the front burner for potato grower-shippers in Colorado’s San Luis Valley.

“Historically we’ve had abundant water, but we kind of overmined our aquifer,” said Jim Ehrlich, executive director of the Colorado Potato Administrative Committee, Monte Vista.

The potential for an irrigation water shortage will not affect the 2010-11 deal.

“We’re pretty much done with the growing season,” said Lee Jackson, operations manager for Farm Fresh Direct LLC, Monte Vista.

Growers had vine-killed about half of the valley’s potato acreage, he said in mid-August. It is the future, however, that concerns the area’s close-knit potato community.

The valley’s dilemma is an unusual situation in that much of the growing area for potatoes — and other crops — is atop a closed basin, said Carla Worley, partner at Hi-Land Potato Co., Monte Vista.

More than a century ago, the state began to construct canals to deliver Rio Grande River water to parts of south central Colorado.

“They crossed the divide from the river to the closed basin, and it sort of filled up the bathtub,” Worley said.

Lower rainfall totals in recent years have meant fewer diversions and less water being put back into the valley’s aquifer, she said. It is a problem the industry began to address in 2003.

“We’ve been looking at working together as an industry — working as a community — instead of doing individual plans,” Worley said. “We’re working with one another and looking at the whole situation.”

Discussions have included water subdistricts designed to bring everything back into balance, Ehrlich said, though litigation has been a hold up.

New laws passed by the Colorado Legislature “now allow us to regulate water as a community and to charge assessments to users,” Worley said.

Building ponding basins to recharge the aquifer is a common practice among many grower-shippers.

“One solution could be to charge larger assessments to those growers who don’t recharge,” Worley said.

Another potential solution is to switch to more effective irrigation methods, she said. Most growers use center-pivot irrigation systems and use wells to provide the water. A smaller number of growers use linear sprinklers.

Researchers at Colorado State University, Fort Collins, are conducting experiments with drip irrigation systems, but the porous soil in the San Luis Valley does not lend itself to drip, Worley said.

Addressing the potential of a water shortage before it becomes a reality should put to rest any concerns that the valley will disappear as a potato growing region.

“It’s not a matter of running out of water,” Worley said. “It’s just that it’s probably going to be more expensive.”