Idaho is a big state stretching nearly 500 miles from the Canadian border to the Nevada/Utah border.
The climate of northern Idaho is much like the rest of the Pacific Northwest. There, water falls from the sky in substantial quantities. But, southern Idaho is a different story.
For instance, Twin Falls gets, on average, only 9.36 inches of precipitation a year. That’s enough water to grow rather small sagebrush but not much else.
My neck of the woods, Idaho Falls, doesn’t do much better, with less than 11 inches of precipitation in an average year.
As a result of limited rainfall, Southern Idaho is one of the parts of the United States most vulnerable to water shortages in drought years. In the 1920s and 1930s, Idaho was hit hard by a lengthy drought. In modern times, droughts have been more separated but still can have significant impact when precipitation is limited.
Southern Idaho’s farms, ranches, businesses and municipalities are dependent on the availability of water primarily from an intricate system of wells and diversions from the Snake River and other rivers and streams.
Under Article XV of the Idaho Constitution, water is declared a “public use” and is regulated by the State of Idaho. Water can be appropriated for private use with priority given to domestic, agriculture, mining and manufacturing uses in that order.
Water is appropriated by users under the doctrine of prior appropriation, which means a water right is created when water is diverted and applied to a beneficial use, establishing a right against others based on the date of first diversion for the amount of water then diverted.
So, if on August 17, 1890, your predecessor on your land built a ditch from a local stream that diverted a certain quantity of water, your right would have that priority date which would protect your use of water from anyone with a water right after that date. In a year you are shortchanged, you can request a “call of the river” asking the Idaho Department of Water Resources to cut off water use by those upstream from you who have junior rights, ie. with dates after your initial priority date. The impact of such calls can be dramatic.
Last year, Rangen, Inc., primarily known as a Magic Valley feed supplier, requested an upstream curtailment to preserve water for its fish farm near Hagerman. The request impacted a vast area consisting of 14 Idaho cities, 200 livestock operations (mostly dairies) and encompassing 157,000 acres of ground (that is 245 square miles). Later, over 322,000 acres of irrigated land in Eastern Idaho were added (over 500 square miles of surface area).
The University of Idaho calculated the lost farm revenues from just the Magic Valley portion of the water call. Their estimate was that impact would be between $163 million to $179 million in diminished crop sales, plus a substantial loss of jobs.
Luckily, the Rangen water call was averted by building a pipeline to their fish farm. But, the pressure on Idaho’s limited water resources continues to grow. The massive aquifer which stretches from Ashton to the Magic Valley with water equivalent to Lake Erie has been shrinking for decades, primarily because of diminished flood irrigation. There are efforts to recharge by diverting additional surface water into the aquifer. But such efforts require surplus water.
Particularly vulnerable to water shortages are Idaho’s cities, many of which lack sufficient water rights for future growth. Domestic well water is given priority in Idaho but municipal systems provide water for multiple uses, thus taking them outside the domestic use protection. Thus, city water providers must compete for water rights with every other user. Many Idaho systems lack sufficient senior water rights to guarantee sufficient water in drought years.
Conservation has a role to play. Many municipal systems have older pipes that leak, wasting water. Agriculture water can be stretched further by lining canals to limit leakage. But, such an approach is expensive and has the side effect of reducing seepage to the aquifer.
Some users exceed their entitlement. Domestic well users in Idaho are only entitled to water one-half acre from their well. Many water far more ground. Expect future crackdowns.
Could Idaho boost the quantity of water available? Perhaps.
The Idaho Water Resource Board is experimenting this winter with a $200,000 aerial cloud seeding project. The goal is to boost the snowpack on Idaho’s mountains.
For some years, a proposal has circulated in eastern Idaho to rebuild the Teton Dam (the source of the massive 1976 flood) to add additional storage capacity. Such would likely draw significant opposition from the residents of Sugar City and Rexburg who were hard hit in 1976. But, this may be more a question of getting the engineering right.
Private partners might also have a role to play. Many, if not most, of the canals in Idaho were built under the Carey Act, which granted newly-watered land to canal builders, which could then be resold for a profit. That system was the primary driver behind the development of agriculture in much of the Snake River Plain.
Maybe Idaho needs a system of incentives to increase private development of new water resources.
Last Friday’s New York Times carried a story about private attempts in California to provide additional sources of water for that drought-wracked state. The two highlighted examples were a ocean water desalinization plant to provide 10% of San Diego’s municipal water and a 34,000 acre project in the Mojave Desert to tap billions of gallons of deep water through a massive well system at the cost of hundreds of millions of dollars.
The Idaho equivalents might be private efforts to develop ultra-deep wells in the Snake River Plain, removing salt or other containments from water that is currently unsuitable, or other creative approaches. The Idaho Legislature might want to consider incentives for such efforts to add to the Idaho water supply in the future.