Mike McVay, an IDWR hydrogeologist, explained his method for estimating the change in the volume of water stored in the ESPA, which relies on water level measurements from 269 groundwater 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 is trending upward over the last 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,” noted 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 (IGWA) and the Surface Water Coalition, IGWA has met and exceeded their annual target of 240,000 acre-feet of water in the last 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.