Aquifer sustainability

Aquifer sustainability

David Sparks Ph.D.
David Sparks Ph.D.
The 2009 Eastern Snake Plain Aquifer Comprehensive Aquifer Management Plan was designed to restore the aquifer to sustainable levels. Ten years later, significant progress has been made to meet the ESPA CAMP’s long-term goal of restoring 600,000 acre-feet water to the ESPA on an annual basis by 2030, staff officials reported to the Idaho Water Resource Board last week.

At the present time, more than 500,000 acre-feet of water is being restored to the aquifer on an annual basis as a result of multiple efforts by the board and stakeholders in the region.

A 10-year review of the ESPA CAMP was requested by Idaho House Speaker Scott Bedke last May, with a report due to the Idaho Legislature and Gov. Brad Little by the beginning of the 2020 legislative session.

A series of board committee meetings have been scheduled to review the progress of stabilization activities on the ESPA. During the Joint Aquifer Stabilization and Planning Committee meeting last week, a number of groups testified in support of the board’s sustainability initiatives and complimented the board, and other participants, for moving ahead aggressively on ESPA restoration initiatives.

Lynn Tominaga, executive director of the Idaho Ground Water Appropriators , noted that under the 2015 historic water settlement between IGWA and the Surface Water Coalition, an average of 240,000 acre-feet of water is being restored to the ESPA each year through reductions in ground water pumping and reduced acres being irrigated. “We’re all working together to stabilize the aquifer,” Tominaga said. “Ground water users have been doing their share. We compliment the board for all of their work, and we need to keep pushing ahead toward ESPA sustainability.”

“The CAMP is working; the science says it’s working,” added Brian Olmstead, general manager of the Twin Falls Canal Company and a spokesman for the Surface Water Coalition. “We are all working together. We applaud and support the board’s recharge program and other initiatives. We need everybody who’s involved in stabilizing the aquifer to continue their work.”

That said, Olmstead said the state cannot allow any further development of farmland in the ESPA region, and it should support improvements in water quality in the mid-Snake region.

Idaho Power Company officials also supported the board’s multi-pronged efforts to restore the ESPA, including ongoing efforts to recharge an annual average of 250,000 acre-feet into the aquifer, but expressed concern about reduced winter flows for generating hydropower.

“We have seen the value of the ESPA aquifer recharge program, and we have supported it. That hasn’t changed,” said Kresta Davis-Butts, senior manager of resource planning and operations hydrology for Idaho Power.

Idaho Power is a net importer of energy in the winter months, which can increase the cost of electricity for customers, she said. It would be valuable to have some water flows passing Milner Dam in the winter months, while the board’s ESPA recharge program is in full swing, to help with hydropower production, and with water quality, fisheries and recreation, she said.

Asked how much more flow Idaho Power would like during that time, Davis-Butts did not give a number. “We’re not seeing a negative impact right now, but if we have zero flow at Milner in the winter, there are consequences,” she said. “Winter hydro production is important.”

The board has a decreed water right for its winter recharge program. Under state law, hydropower production is subordinate to other water rights. However, Water Board Chairman Roger Chase said the board would pay close attention to the issue and balancing aquifer-sustainability interests with Idaho Power’s concerns.

In other business, the board:

Approved funds to cost-share the development of four injection wells with the A&B Irrigation District and two injection wells with the Twin Falls Canal Company for the board’s ESPA recharge program.

Approved spending $204,000 for the first year of a five-year study on the Raft River hydrologic basin. The Raft River area has been designated as a Critical Ground Water Area since 1963. Since that time, ground water levels have continued to decline, depending on location. Other entities will contribute to the study, staff officials said.

Took a field trip to Anderson Ranch Dam with Bureau of Reclamation officials to learn about technical design considerations and other issues that will be addressed in an environmental impact study for a 6-foot raise of the dam to create 29,000 acre-feet of new water storage. A final EIS will be issued by the BOR in July 2020.

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