Idaho Water Resource Board reports $575 million since 2019; highlights recharge, Anderson Ranch raise and cloud‑seeding

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 summarized how the board has allocated funds for regional water sustainability projects, aging infrastructure grants, cloud seeding, ESPA recharge infrastructure and other projects.

Raybould provided program details and recent results: the board’s water management account holds roughly $337 million in principal and interest; ARPA monies of $250 million have been used for major projects including Anderson Ranch Dam raise, the Mountain Home Air Force Base pipeline, ESPA recharge infrastructure, American Falls spillway repair, the Lewiston Orchards exchange project and the New York Canal rehabilitation.

On recharge and capacity the board presented averages and capacity numbers: modeling and project data cited by the board show state‑sponsored managed recharge averaged about 268,000 acre‑feet per year from 2016–2023 and private pumping reductions and private recharge averaged about 341,000 acre‑feet per year over the same period — a combined average near 600,000 acre‑feet. Raybould said current recharge capacity is roughly 2,000 cubic feet per second in the Lower Valley and nearly 600 cfs in the Upper Valley, and the board estimates significantly more Upper Valley capacity is needed to capture high runoff years.

Major projects and grants noted in testimony: - Anderson Ranch Dam raise: a 6‑foot raise to add about 29,000 acre‑feet of storage; estimated cost just under $126 million, with approximately 11% federal participation under the WIIN (WIIN/WIIN‑type) authorization; construction anticipated in 2026. - Mountain Home Air Force Base pipeline: state constructing the transmission pipeline (estimated $40 million) to deliver a sustainable raw‑water supply; Air Force building a treatment plant, with completion expected in 2026. - Aging Infrastructure Grant Program: competitive grants covering up to one‑third of project costs (cap $2 million per project); $56 million awarded across 90 projects in five rounds. - Groundwater‑to‑surface‑water conversion grants: up to 50% of project costs (cap $5 million); 11 grants awarded totaling roughly $13 million. - ESPA telemetry and monitoring grants: up to 50% of telemetry costs, up to $250,000 per award; applications due March 28 (as announced in testimony). - New York Canal rehabilitation: lining and lining fabric with concrete to reduce breach risk; board said lining could reduce incidental recharge but concluded safety risks near populated benches justified the initial six‑mile lining and board will pursue compensating recharge elsewhere.

Cloud seeding: Raybould described a cooperative cloud‑seeding program operated by Idaho Power with board and local user funding: three aircraft, 57 generators, and meteorological support. The board stated the program produces an average additional runoff of about 950,000 acre‑feet and an average operational cost of about $3.77 per acre‑foot.

On unrecovered spill past Milner Dam, Raybould said on average roughly 1.7 million acre‑feet passes Milner in years when capture capacity is limited; in a large water year the total can be much higher. He and board staff urged a balanced approach to deciding how much infrastructure to build to capture occasional large flows and how much to invest to stabilize aquifers in high‑runoff years without overbuilding for rare conditions.

Ending: Raybould said the board is working statewide and will continue to prioritize recharge, infrastructure and measurement, and he described planned pilot efforts (Treasure Valley recharge pilot) and an increased focus on Upper Valley recharge capacity.