Agreement settles water rift in nation’s top potato-producing state
Irrigation water is the lifeblood of agriculture in western states. Desert or rangeland awaited early settlers, who had to divert water from streams and rivers or dig canals to bring the vital resource to farms from reservoirs.
Water is particularly important — and can be contentious — in the nation’s top potato-producing state.
Water use in Idaho, which produced 145 million cwt. of potatoes in 2023 and sees growers harvest between 300,000- 320,000 acres each year, is governed by the prior appropriation doctrine. The doctrine gives senior water rights holders (the earliest users of the water) priority over junior rights holders. During shortages, senior appropriators are allowed to use all of their allotted water, while junior users may receive some or none of their allotment.
With a water shortfall forecasted earlier this year, the Idaho Department of Water Resources (IDWR) issued a curtailment order requiring 6,400 junior water rights holders who pump off the Eastern Snake Plain Aquifer to shut off their water. At the time of the May 30 order, the department projected that the senior water rights users in the Twin Falls Canal Co. could face a water shortage of 74,100 acre-feet.
An acre-foot is a unit of volume that measures the amount of water it would take to cover an acre of land in water one foot deep.
An outcry arose from owners of the up to 500,000 acres in eastern Idaho at risk of curtailment. Many irrigators had to turn off water in the middle of the growing season.
The curtailment order stayed in place for three weeks until an agreement ended it for 2024. Idaho Gov. Brad Little issued an executive order mandating a new, long-term deal be reached by Oct. 1.
In November, a long-term agreement was ratified by members of the Idaho Surface Water Coalition and the Idaho Ground Water Association. The new agreement gives groundwater users their water allotment in four-year increments instead of determining allocations one year at a time. It also calls for groundwater districts to conserve a minimum of 205,000 acre- feet of water annually.
“It was a tough year of negotiations, but I never doubted our farmers could get this done,” Little said in a written statement. “Idahoans have always solved our own problems, and the new mitigation plan charts a better path for all water users in the years ahead while ensuring Idahoans maintain control of our water destiny.”
FIRST IN TIME, FIRST IN RIGHT
Idaho’s water history is a complicated tale. Every water right has a date when it was applied for when the land was homesteaded. The prior appropriation doctrine established senior and junior water rights, also known as first in time, first in right.
In addition, the state’s irrigation water is managed as one resource, with surface water and groundwater managed together.
“If a senior right is being injured by a junior right, the junior has to shut off or cut back until the senior right has its water,” said Scott Bedke, a farmer/rancher and Idaho’s lieutenant governor. “This can be disruptive to the local economy when it is strictly enforced with no modifications. The only thing you can do legally to modify the prior appropriations doctrine is create mitigation plans.”
Personal relationships can also be affected. Imagine Property A’s original owner moved into the area 140 years ago, settled in the lower end of a valley with a stream running through it and established the first water right, irrigating from that stream. Property B’s first owners settled in the upper part of the valley 10 years later.
“The families have lived next to each other for decades, their kids married and they become a community,” Bedke said. “But the people on farm B know that if farm A needs the water, the B farm must shut off or cut down their use, to satisfy the right for farm A.”
If the farm owners work out ways to solve the issue, that mitigation plan is filed with IDWR, whose director must sign off on it.
“If we do the things on the list, irrigators gain a safe harbor from the harshness of prior appropriation; the mitigation plan shields folks from suddenly having to turn off their water,” Bedke said.
Those plans become more complicated as more irrigators are added. Bedke and co-mediator Jeff Raybould, IDWR board chairman, created a mitigation plan in 2009 and again in 2016.
The newest version, the 2024 Stipulated Mitigation Plan entered into with nine groundwater districts across the Eastern Snake Plain Aquifer, features four key components:
PROPORTIONALITY
Under the 2016 agreement, everyone had to follow the mitigation steps. “All nine groundwater districts were stuck with each other; if one didn’t perform, either the others had to pick up the slack or they all were in breach of the agreement and all got penalized,” Bedke said. “That was unfair. So we created a system in which if you do yours, then you enjoy safe harbor and if I don’t do mine, I get all the consequences of not following the agreement.
“When you have done your responsibility, you acquire your prorated share.”
RECHARGE
Recharge occurs when water seeps into the ground to replenish underground aquifers. Although some recharge happens incidentally, intentional recharge can restore groundwater levels and store water for later use.
“The 205,000 acre-feet of pumping reduction leaves me with a certain amount that I can pump,” Bedke said. “I want to be able, through my own devices, to improve my allocation. Enter private recharge. All recharge is not created equal, however.”
Senior rights holders experience a leach gain between Blackfoot and Minidoka, with Twin Falls Canal Co.’s water entering the river between those two areas, he said.
“In order to get credit and increase their allocation, they need to recharge in an area where the water will go into the river and is connected and hydrologically significant to that leach gain,” Bedke said. “If they can do this, they get credit for private recharge, which can increase their allocation.”
AVERAGING
Crop rotation, and the water requirements of different crops, also play a role.
“If I’m going to put water into the aquifer on a good year so I can take it out on a bad year, I’ve got to be able to average my water use,” Bedke said. “This is simple math, but it’s never simple because one year I grow barley and the next year I grow potatoes.”
The four-year increments allocated in the new agreement can influence crop rotation decisions.
“Having a four-year block of water allows for management decisions at the farm level and not by the state or water district,” Bedke said. “The farmer gets a block of water and can choose to maybe use 20% of it one year, and 35% the next year. But when it’s gone, it’s gone.”
MEASURING
The four-year allocations make accurate, transparent data collection paramount, “so everyone knows where the neighbors are in their water use and farm managers know where they are in terms of allocations,” Bedke said.
Future water usage could also be affected by other factors including projects currently in the works, such as drilling recharge wells or managed recharge programs that convert groundwater farms to surface water farms.
“These will all help,” Bedke said. “There won’t be one answer; there might be 100 answers on how we do this. Every locality has some unique things they can do.”
The four-year water block allotments create a de facto trial period that can help make the road ahead clearer, he said.
“We’ll see how it goes for those four years, and if it’s going well, the agreement extends for another four years, and so on,” Bedke said. “We can look at it again every four years to make sure it’s working.”
