Idaho Water Resource Board reviews $575 million in projects, ARPA allocations and recharge work

Jeff Raybould, chairman of the Idaho Water Resource Board, told the House Resources Committee the board has received roughly $575 million in appropriations since 2019 and manages programs spanning aging‑infrastructure grants, ARPA‑funded projects, recharge and cloud‑seeding partnerships, and regional sustainability initiatives.

Raybould said the board’s Water Management Account holds roughly $337 million in principal and interest and that about $250 million in ARPA funds were allocated to projects including an Anderson Ranch Dam raise, a Mountain Home Air Force Base pipeline project, ESPA recharge infrastructure, American Falls Dam spillway repair, the New York Canal rehabilitation, and other regional investments.

He outlined several grant programs: an aging‑infrastructure competitive grant program that covers up to one‑third of project cost (maximum $2 million per project) and has awarded about $56 million to 90 projects; a groundwater‑to‑surface‑water conversion grant (up to 50% of project cost, capped at $5 million) that has awarded roughly $13 million across 11 grants; and a telemetry and monitoring grant to fund telemetry installations (up to 50% of eligible cost, maximum $250,000) with applications due March 28.

Raybould described the board’s cooperative cloud‑seeding program — operated by Idaho Power with board and local funding — that uses three aircraft, 57 generators and weather instruments and averages additional runoff in targeted basins at a reported average cost of about $3.77 per acre‑foot.

He reviewed ongoing and planned capital projects: Anderson Ranch Dam raise (estimated additional 29,000 acre‑feet with a six‑foot raise; design ~60% complete; partial federal cost share under the WIIN Act), the Mountain Home Air Force Base pipeline (state‑funded transmission to be completed in 2025; Air Force water‑treatment plant scheduled for 2026), American Falls spillway rehabilitation, Lewiston Orchards exchange, New York Canal rehabilitation (liner and cement cover to reduce breach risk in Boise area), Raft River pipeline, and other regional water‑supply and recharge projects.

On ESPA recharge capacity, Raybould said the board currently has roughly 2,000 cfs capacity in the Lower Valley and nearly 600 cfs in the Upper Valley and recommended expanding Upper Valley capacity, estimating the state likely needs several times the current capacity to capture high‑runoff years and stabilize the aquifer. He said last year more than 600,000 acre‑feet of water passed Milner Dam unused when recharge or storage capacity was insufficient; on longer averages the board estimates about 1.7 million acre‑feet can pass Milner in years with high runoff.

Members questioned incidental‑recharge effects when canals are lined (which reduces leakage into aquifers). Raybould said the board weighs safety and infrastructure risk against lost incidental recharge and, in the New York Canal project, expects incidental recharge loss on the order of 25,000–30,000 acre‑feet per year for the section being lined; the board is exploring compensatory recharge options elsewhere in Treasure Valley.

Raybould said the board is pursuing both upper‑basin recharge capacity and projects to capture winter flows that now pass Milner, and that funding choices must balance expected frequency of high‑runoff years against infrastructure cost.