In this arid climate, Treasure Valley communities depend on three Boise River reservoirs that together provide nearly a million acre feet of water storage. The storage is usually adequate to meet the need for irrigation water, but this year, some of the valleys irrigation districts and canal companies stopped delivering water to farms, schools and subdivisions in early September because of low water supplies.
While uncommon and unfortunate, short water years are not unexpected or unprecedented. The Treasure Valley has experienced numerous droughts, but changing climate patterns may decrease the reliability of winter snowfall even further.
On Sept. 20, the Idaho Statesman printed an opinion by Tim Page, manager of the Boise Project Board of Control. Page described the shortage his irrigation districts endured this year and appropriately expressed concern for future drought. Page suggested more reservoir storage may be needed.
New or higher dams, however, wont create new water; even our smartest engineers cant make it snow. So instead of depending on Congress to appropriate millions to study and design new storage space, we need to invest those dollars into implementing changes to eliminate inefficiencies and make the best use of every acre foot of water we have.
One way to do this would be to stop diverting more water than needed to serve suburban and commercial areas. Buildings, roads and parking lots occupy thousands of acres that were farmed in the 20th century. Development happened so fast and so extensively that irrigation entities havent had the chance to work with municipalities and homeowners associations to make the adjustments necessary to ensure excess water isnt diverted.
When water is plentiful, few take time to worry about efficiency, but this year it wasnt. This year, delivering water as if farms dominated the landscape exacerbated the impacts of a low snowpack.
The premise here is straightforward: Irrigation districts and canal companies should divert only the amounts necessary to deliver water to the lands in their service areas that are actually irrigated. Rather than pushing as much as two times more water than a given parcel can use, the irrigation entities should leave the water in reservoir storage or in the river for other users who, in turn, would not have to call on storage as often or as early. Diverting more than is needed means water flows past subdivisions unused and ends up back in the river via drains and creeks.
The irrigation districts and canal companies may recite various justifications for diverting as much water as they do, but before more money is spent studying additional storage, critical information needs to be shared.
How many acres of irrigable land do the irrigation interests serve? How much water is being diverted per irrigated acre? Which subdivisions use a timed rotation to share water supplies? How much water is showing up in drains or as increased river flows at the state line?
Irrigation accounts for more than 90 percent of the Treasure Valleys water diversions. Bringing suburban lawn and landscaping irrigation into line with the per-irrigated-acre diversions that apply to the Valleys farmers would yield significant water savings. This course of action provides reliable insurance against drought and allows local stakeholders to act now instead of waiting indefinitely for Congressional appropriations to build new storage to capture runoff from snow that may never fall.
Improved efficiency is the quickest, cheapest and most reliable way to drought-proof the Treasure Valley.
Liz Paul is Boise River Campaign Coordinator for Idaho Rivers United.