Idaho Water Resource board lays out aquifer recharge plans

The Idaho Water Resource Board hopes to recharge 80,000 acre-feet of water into the Eastern Snake Plain Aquifer this winter.

Since October, approximately 36,000 acre-feet has been returned to the aquifer.

The board said the target would have been higher if necessary infrastructure was complete. Recharge project manager Wesley Hipke said a number of potential canals and recharge basins would not be available until next year.

There now are two canal companies participating in recharge in the mid-Snake region, including the Milner-Gooding Canal operated by the American Falls Reservoir District No. 2 and Twin Falls Canal Co. The North Side Canal Company and Southwest Irrigation District conducted recharge at the start of the season but shut down during the coldest months. They plan to restart in the spring. Future projects are being considered that would allow these entities to recharge through the winter.

In the Upper Snake River Valley, three construction projects are under way to boost recharge capacity, among other things:

New head gates are being built in the Great Feeder Canal near Rigby at an approximate cost of $1.2million at the main diversion location on the South Fork of the Snake River. The new head gates were needed for basic canal operations but they also will help with recharge. The Water Board is contributing $500,000 to that project.
New flow control structures and measurement devices are being installed at the Jenson Grove spreading basin in Blackfoot next to I-84 at a cost of $53,000. The Water Board is contributing $26,500 to that project.
A new recharge canal is being built in the Egin Lakes recharge area near St. Anthony to increase recharge capacity from 50 cfs to 150 cfs per year. The Water Board is paying for the full cost of that $1,030,000 project because it is being built solely for recharge. The Water Board will have exclusive rights to use the Egin Lakes recharge area when the Board’s water is available.

The Egin Lakes project is scheduled to be completed by March and will be operable if surplus flows are available for recharge, Hipke said. “The idea is to create as much recharge infrastructure as possible so we can recharge water when we have it,” he said.

The Water Board has a water right for approximately 1,200 cubic feet per second to divert water from the Snake River for recharge. However, the board is not counting on any recharge water to be available in the upper valley this year because runoff is likely going to be used to fill the reservoir system.