Irrigation canals to keep flowing well after harvest
By DAVE WILKINS
An aquifer-recharge project will keep water flowing through some Idaho irrigation canals after most crops have been harvested this fall.
The Idaho Water Resource Board approved a plan to divert between 30,000 and 60,000 acre-feet of water back into the Eastern Snake Plain Aquifer from mid-October to mid-November. The actual amount will depend on weather conditions and the availability of water and canals to carry it, state officials said.
The majority of the recharge will take place below American Falls Reservoir using natural-flow water under the board's water right. Some recharge will also occur above American Falls at Egin Lakes using storage water leased by the board from the Fremont-Madison Irrigation District.
The water will be released into canals at the conclusion of the irrigation season and then allowed to seep into the aquifer rather than be diverted into farmers' fields.
The board allocated $200,000 for the late-season recharge project and agreed to pay water conveyance fees of up to $3 per acre-foot.
Recharge has been identified as a key component of the state's plan to balance supply and demand on the Eastern Snake Plain Aquifer.
The Lake Erie-sized underground resource provides water for homes, crops, livestock and fish farms across much of Southern Idaho.
The late-season recharge project was made possible by good snow accumulation last year, a cool wet spring and expectations for adequate reservoir carryover storage above American Falls this winter, said Bob McLaughlin, a spokesman for the Idaho Department of Water Resources.
A similar recharge project in March and April prior to the irrigation season resulted in 104,000 acre-feet of water being recharged in the Upper Snake River basin, state water officials said.
Participating canal companies and irrigation districts included the American Falls Reservoir District No. 2, Fremont-Madison Irrigation District, Idaho Irrigation District, Aberdeen-Springfield Canal Co., the Burgess Canal and Irrigation Co. and the Harrison Canal and Irrigation Co.
Changing irrigation practices, including the widespread conversion of gravity-flow irrigation to sprinkler systems and increased groundwater pumping, have contributed to declining aquifer levels, experts agree.
Staff writer Dave Wilkins is based in Twin Falls. E-mail: firstname.lastname@example.org .