BOISE — Recent water level monitoring data shows the volume of water stored in the Eastern Snake Plain Aquifer has increased by about 350,000 acre-feet in the past year and 2.2 million acre-feet in the past five years, officials told the Idaho Water Resource Board Thursday.
Mike McVay, an IDWR hydrogeologist, explained his method for estimating the change in the volume of water stored int he ESPA, which relies on water level measurements from 269 ground water wells and a conservative approach to provide more confidence in long-term trends.
“I removed some of the flashier wells that are close to recharge sites to increase our confidence,” McVay said.
Aquifer discharge in the Thousand Springs area and along the Snake River between Blackfoot and Minidoka also are trending upward over the past five years, IDWR hydrologists said.
“If we’re seeing higher levels in the aquifer, we should be seeing higher discharge from the springs, the primary outlet for the aquifer,” said Matt Anders, IDWR hydrologist.
In an annual accounting of the aquifer withdrawal reductions agreed to by ESPA groundwater users in the 2015 historic water settlement between the Idaho Ground Water Appropriators and the Surface Water Coalition, IGWA has met and exceeded their annual target of 240,000 acre-feet of water in the past year, officials said.
IGWA members reduced groundwater use by 260,000 acre-feet and provided an additional 90,000 acre-feet of water as aquifer recharge, said Brian Ragan, an IDWR hydrologist who tracks the settlement agreement on an ongoing basis.
“What a great time to work on water resources because I get to share in your accomplishments,” IDWR Director Gary Spackman told the board.
“It’s great to see the upward trend continuing,” added board Chairman Roger Chase. “Our plan is working.”
In other news, the Board approved 12 flood-management grants statewide at a cost of $860,000. The Board followed staff recommendations and rankings of 14 projects that were submitted statewide.
The grantees are as follows: Lewis Soil Conservation District, $18,425; Clearwater Soil and Water Conservation District, $24,687; City of Bellevue, $57,880; Twin Falls Canal Company and City of Twin Falls, $51,000; Flood Control District #10 — Eagle Island North Channel project, $47,500; Flood Control District #10 — Canyon County project; $175,000, City of Orofino, $200,000; Idaho Soil and Water Conservation District — Lower Cottonwood Cr. project, $27,935; Idaho Soil and Water Conservation District — Sill Creek project -$10,96010.Idaho Soil and Water Conservation District –Clear Creek project, $18,570; Raft River Flood Control District #15, $80,525; Pioneer Irrigation District, $148,500.
All projects required a 50% match.
In other action, the Board received a briefing on the Boise River Feasibility Study, which is evaluating the feasibility of raising Anderson Ranch Dam by up to 6 feet on the South Fork of the Boise River to create more storage water. A Draft Environmental Impact Statement was released on July 31, on the BOR’s web site: https://www.usbr.gov/pn/studies/boisefeasibility/index.html.
The public comment period opened on July 31 and will close on Sept. 14, BOR officials said. A virtual public meeting is planned for Aug. 26 from 6-8 p.m. The Board also approved the use of funds from the Idaho National Laboratory and U.S. Department of Energy to track ground water levels and water quality in the Raft River area.