Idaho aquifer recharge marks record year

The Idaho Water Resource Board has approved $730,000 for two new projects intended to increase the capacity of the board’s managed recharge program. The action came during a two-day meeting in Idaho Falls last week. One will add an additional 100 cubic feet per second (cfs) of recharge capacity from the Big Wood and Little Wood rivers. That project is estimated to cost around $150,000. In the Upper Snake River Valley, the board approved $580,000 to expand the Egin Lakes recharge canal. Recharge Project Manager Wesley Hipke said it would expand the project by 60 cfs. A hydropower bypass project is also under development that will increase wintertime recharge capacity in the North Side Canal by 130 cfs. Hipke said the historic winter of 2016-17 enabled the board to recharge a record 317,714 acre feet of water into the Eastern Snake Plain Aquifer (ESPA). The board’s goal is an average of 250,000 acre feet of water each year.
The recharge cost $2.4 million in conveyance fees to participating canal companies and irrigation districts. The companies and districts are compensated based on the number of days and amount of water delivered. The board intends to develop enough system recharge capacity to maximize recharge diversions during high water years. “We are continuing to look for new recharge partners to expand our recharge capacity and provide flexibility and redundancy in the system,” Hipke said. The 250,000 acre-feet annual goal can be met if at least 840 cfs is recharged for 150 days. This year, the board was able to recharge for over 221 days. “This was a perfect example of the need for enough system capacity and recharge partners to make the most of a year with abundant water supply,” Hipke said. The Water Resource Board is continuing to study options for surface water storage as well. The panel toured Island Park Reservoir shoreline properties and infrastructure during its Idaho Falls visit. The board has hired a consultant to evaluate the potential effects of raising the water surface elevation of the reservoir. That expansion might be used to improve recreation and fishery conditions in the reservoir and the river downstream as well as provide additional storage water for use in the Henry’s Fork Basin, on the ESPA recharge, or to meet minimum stream flows downstream.