A historic water agreement approved in 2015 to resolve decades of litigation between the Eastern Snake Plain’s groundwater and surface water users could soon face its toughest test yet, Idaho House Speaker Scott Bedke said.
The Eastern Snake Plain Aquifer supplies water to about 2 million acres of farmland, as well as cities and industries. About half of the irrigation supply is surface water, and half is pumped from wells.
Aquifer levels have been declining since the 1950s due to increased well irrigation, thereby depleting springs that bolster river flows and injuring surface water irrigators with senior water rights. Years of drought and the increased use of efficient sprinklers rather than flood irrigation, which allows excess water to seep back into the aquifer, have also played a role in the declining aquifer levels.
During the 2015 season, passage of the water call settlement prevented the drying of more than 400,000 acres of groundwater-irrigated agricultural land, according to Bedke, R-Oakley. The agreement has also been crucial in during the current drought year.
“This year was a year much like that one, and you would have been looking down the barrel of 150,000 to 200,000 acres that would have been shut off,” Bedke said. “The agreement covered all of that.”
As Bedke noted, however, having back to back drought years would really put a strain on the agreement.
“If we don’t get about 120 percent of normal precipitation this year, it’s only at that point, that much above average, that any of the seniors get a full water right,” Bedke said. “We do still live in the arid West and this part of the state is agricultural, based on production and processing and everything that comes around it.”
Under the agreement’s terms, participating groundwater users were given safe harbor from water calls. In exchange, they agreed to reduce their groundwater use by 240,000 acre-fee per year, representing a reduction of about 12 percent from historic use. They also agreed to lease and deliver 50,000 acre-feet of storage water annually to the senior irrigators, represented by the Surface Water Coalition. Furthermore, they had to install meters on wells by 2018, among other provisions.
The agreement included benchmarks to be met toward recovering the aquifer.
To help in the effort, the state agreed to recharge an average of 250,000 acre-feet of water into the aquifer each year. Managed recharge entails intentionally allowing surface water to seep into the groundwater by running it into gravel pits, spill basins or through unlined canals in strategic locations.
“We stopped the drop in the aquifer and we’re building back. We met the state’s goals and the agreement’s goals to put 250,000 acre-feet back into the aquifer each year,” Bedke said. “In fact, for this year we’re averaging 387,000 acre-feet.”
Nonetheless, Bedke acknowledged the upcoming milestones established under the agreement may be out of reach due to the recent drought.
“They did set themselves goals to be at certain levels by certain dates. It’s highly unlikely now at the trajectory we’re on that we hit the 2026 goal,” Bedke said, emphasizing that the agreement is adaptive to changing circumstances.
Bedke believes the agreement has also eliminated the bad blood of the past between irrigators, which should make it easier to resolve any challenges on the horizon.
He believes irrigators are understanding “maybe we’re not getting everything we want but we’re getting everything we need. We don’t want to put our neighbors out of business.
“There’s just a little bit more good will in the conversation than there was before,” said Bedke, who was instrumental in getting the sides to reach the settlement. “If we go back to back (dry years) it will test all of that.”
The Idaho Water Resource Board is now mulling three options for creating new managed aquifer recharge sites in the Upper Snake River Valley. Two of the state’s proposals would entail building pipelines and pumping water to a spill basin — adding power bills to the cost of recharging water.
One pipeline would pass beneath Interstate 15 and transport water to a spill basin within the lava flows of Hell’s Half Acre, located between Blackfoot and Idaho Falls. The second pipeline would pump water from the Roberts area to a spill basin near Mud Lake.
The third project would avoid the need for pumping. Water would be gravity fed east of the state’s current Egin Bench recharge site into a spill basin within lava fields.
All three project sites have been strategically selected to retain water in the aquifer for as long as possible.
Bedke believes the pipeline to Mud Lake would cost prohibitive. He believes the Egin Bench project is a good possibility, but he emphasized the state has to start considering projects that retain recharge water in the aquifer for varying lengths of time to space out when it will arrive at springs and become available to surface irrigators.
Bedke said raising Anderson Ranch Dam in Elmore County to add an extra 30,000 acre-feet of storage may be a good option. Furthermore, he said lining the New York Canal and the Aberdeen-Springfield Canal could reduce losses to seepage and improve water management.
Bedke said federal funding from the American Rescue Plan Act of 2021 should be available to help fund development of new recharge infrastructure.