‘On the slow road to demise’: Idaho water system can’t absorb climate change stress

Idaho is in the midst of an ongoing water crisis that threatens a key economic sector: agriculture. Though that crisis has been abated this year by a last-minute deal, it will return.

Climate change is reducing the amount of water available each year. There’s less snowpack, and it melts earlier, extending the period with both little rainfall and little water available for irrigation.

And the way we regulate water exacerbates the problem, encouraging farm closures rather than conservation.

The basic problem is one that will be very hard to solve because it is inherent in the fundamental principle of water management in most of the West: the doctrine of prior appropriation.

Prior appropriation developed in the context of the mid-1800s West.

Imagine the first farmer in an area sets up next to a creek that they divert from time to time to water their field. If a second farmer settles land upstream, what’s to prevent them from diverting and using the entire stream for their farm, putting the first farmer out of business?

The prior appropriation system allows the first farmer to lay claim to the water they need through a water right. And since they were there first, their water right is senior to the second farmer’s. If the first farmer doesn’t get the water they need, they’re allowed to tell the second farmer to stop watering.

This was a sensible system when new farms were being established in large numbers because it prevented more farms from being set up than the water system could handle.

But in the context of climate change, where there’s a little less water each year over time, prior appropriation makes less sense.

Imagine you have 10 farmers using the same river to irrigate their crops. If the amount of water available drops by 10% from its historical level, there are two basic ways to deal with that:

1. The farmer with the most junior water rights goes out of business (and the amount of food produced shrinks by 10%).

2. Everyone finds ways to grow the same crops with 10% less water each by reducing waste.

The second option is obviously better — nobody goes out of business, and there’s more food. But prior appropriation provides no incentive for senior water users to make investments to use water more efficiently. Investments cost money. Curtailing other users is free.

Alan Jackson, the water manager of the Bingham Groundwater District, said these incentives show up clearly in the numbers. The average groundwater user puts between 1.6 and 2.0 feet of water on their land over the course of a year. Surface water users divert closer to 6.5 feet.

Much of that extra water doesn’t actually wind up on fields, Jackson said. It’s sent through canal systems, to ensure that far-off farms have enough water, and then the excess runs off through spillways at the end.

More efficient systems that involve automated gates every few miles can be much more efficient, but they’re expensive.

“There is no incentive for anyone to be any more efficient because if you become more efficient and you use less water, you effectively give that water up,” Jackson said.

Idaho Ground Water Association co-chair Stephanie Mickelsen said the future of Idaho’s agricultural system requires efficiency measures. “It’s going to take all of us, surface and groundwater users, to be able to make this work,” she said.

Unless Idaho can find ways to incentivize efficiency in the use of water, many in eastern Idaho fear farms will simply blink out over time.

“If the only answer to climate change is to shut off acres, we’re on the slow road to demise,” Jackson said.

Bryan Clark is an opinion writer for the Idaho Statesman based in eastern Idaho.