BURLEY, Idaho — While managing flood waters is the most immediate concern for water managers in Southern Idaho, the biggest issue by far is the health of the Eastern Snake River Plain Aquifer.

At the core of the problem is the state’s over-allocation of water rights, water managers told the Water in Idaho and the West conference last week.

“The short of it is we have a real problem out there. We’re mining an aquifer we’re not able to replenish,” said Randy Brown, chairman of the Southwest Irrigation District.

In the past, the state liked handing out water rights but not managing water, he said.

About 25 years ago, the groundwater pumpers in his district saw the writing on the wall and knew they had to address the issue themselves. Landowners in the area spent $60 million on infrastructure to facilitate soft conversions from groundwater use to surface water use and spend about $4 million annually to lease surface water.

That keeps them from tapping about 70,000 acre-feet annually from the aquifer.

They’ve also directly recharged about 5,000 acre-feet a year and have undertaken a new project to recharge as much as 20,000 acre-feet annually.

While those efforts have helped stabilize the aquifer, it’s going to take a lot more to replenish it, he said.

“It’s not a healthy aquifer. Water levels have been going down for years and years and years. We struggle to stabilize it, but the aquifer is not stable by any means,” he said.

The district’s hydrologist measures ground water levels in multiple districts and says those levels are decreasing by 1 to 1-1/2 feet a year. The land mass above the aquifer is 6 million acres, and raising water levels is a monumental task, he said.

“It’s a big problem we need to solve. It takes cooperation, and ground water people need to step up,” he said.

The recent agreement between the Surface Water Coalition and Idaho Ground Water Association — to reduce aquifer consumption by 240,000 acre-feet a year and restore the aquifer to a sustainable level — was monumental, but it’s going to take time to turn the tide, he said.

That agreement is to never let the aquifer fall below 2015 levels, and the goal is to increase ground water levels, said Brian Olmstead, general manager of the Twin Falls Canal Co.

“We’re trying to manage the aquifer as a reservoir,” he said.

Ground water pumpers agreed to a reduction in pumping every year to restore the aquifer. While he doesn’t like to see acres dried up, if the aquifer gets any lower it’ll mean severe reductions for his irrigators, he said.

The agreement sets some pretty high goals over the next 12 years or so, and hopefully they will be met, he said.

“The aquifer has to recover,” he said.

Other issues

With 17 hydroelectric projects in the state, Idaho Power is involved in a lot of water issues around the state and has a long history of conflict with other water uses, said Jon Bowling, the company’s lead engineer on water management.

The company is trying to figure out how to maintain minimum flows at its Swan Falls plant as the Snake River declines.

“Our goal is to provide the lowest-cost reliable energy we can — keep the rates low and the lights on,” he said.

The agreement between surface and groundwater users is a good start to improving the health of the aquifer and spring flows to help maintain minimum flows for generating hydroelectricity, but it sets some tough targets, he said.

The proliferation of domestic wells is another concern. With 6,000 new domestic wells drilled annually, 30,000 acres of cropland annually would have to be dried up to offset the domestic wells going in, said Randy Bingham, former manager of the Burley Irrigation District.

“At some point we have to get a handle on domestic use,” said state Sen. Kelly Anthon, District 27. There needs to be a higher level of accountability for municipalities. Some large cities in Idaho aren’t even metering water usage, he said.

Another issue is the 2 million acre-feet of water that leaves the state every year. That water could be used for recharge, Brown said.

The state’s annual allocation of $5 million for recharge is a drop in the bucket compared to the state’s budget and what is needed, he said.