💧 Idaho Energy Profile

Hells Canyon Complex (1,167 MW)

The Hells Canyon Complex (Idaho Power; FERC License No. 1971; three dams — Brownlee, Oxbow, Hells Canyon — on the Snake River at the Idaho-Oregon border, Hells Canyon gorge) comprises the largest privately-owned hydroelectric development in the United States. The three dams: Brownlee Dam (Idaho Power; 585 MW; 395 ft tall; Brownlee Reservoir — the largest reservoir on the Snake River; completed 1958; generates 2,780 GWh/yr in an average year); Oxbow Dam (190 MW; completed 1961); Hells Canyon Dam (392 MW; 330 ft tall; the lowest of the three; completed 1967; Hells Canyon Reservoir). The Complex generates approximately 3,800–4,500 GWh/yr in average water years — roughly 40% of Idaho Power's annual electricity supply from just three facilities. Idaho Power's FERC relicensing: the original Hells Canyon Complex FERC licence expired in 2003 — Idaho Power has been operating under annual licence extensions since 2003 while negotiating a new 40–50 year licence. The relicensing process is one of the most complex FERC proceedings in US history: it involves FERC, USFWS, NOAA Fisheries, BLM, NPS, Idaho DEQ, Oregon DEQ, Nez Perce Tribe, Shoshone-Bannock Tribes, recreational interests, and downstream irrigators. Key disputed issue: Idaho Power must implement a comprehensive fish passage and habitat programme as a relicensing condition — including trap-and-haul facilities for lamprey, passage improvements for bull trout, and minimum flow regimes. The relicensing settlement (in negotiation): Idaho Power has agreed in principle to a multi-decade environmental enhancement package valued at ~$100–150M for fish and wildlife, in exchange for a new 40–50 year licence. The new licence is expected by 2026–2028.

Four Lower Snake River Dams — Breach Debate

The four Lower Snake River dams (owned and operated by the US Army Corps of Engineers, in partnership with the Bonneville Power Administration which markets their power): Ice Harbor (608 MW; 1962; near Pasco, WA), Lower Monumental (810 MW; 1969; near Kahlotus, WA), Little Goose (810 MW; 1970; near Starbuck, WA), and Lower Granite (810 MW; 1975; Granite, WA — 140 miles inland from the Columbia; the most upstream of the four) are all located in Washington State — but their impact is primarily on Idaho's Snake River basin ecology and energy economics. Total capacity: 3,038 MW (nameplate) — but these are run-of-river dams with very low capacity factors (~20–25%), generating approximately 8–10 TWh/yr in average water years. Salmon context: the four dams converted 140 miles of free-flowing Snake River into a series of slow reservoirs, eliminating approximately 100 miles of critical spawning habitat for Snake River fall chinook salmon, sockeye, steelhead, and bull trout — all now ESA-listed. Snake River sockeye reached as low as 1 wild returning adult in 1994 (the Redfish Lake Creek stock). Snake River spring/summer chinook returns: ~100,000 in 2023 vs. ~1–2 million historically. Breaching option: the Biden Administration's 2023 Columbia Basin Restoration Initiative proposed studying Lower Snake River dam breaching as the primary tool for salmon recovery — replacing their power output with wind and solar. The $1B Columbia Basin Framework agreement (2024) — signed by the Biden administration, Pacific Northwest tribes, and Washington/Oregon governors — included a framework for regional investment in salmon recovery and renewable energy. Idaho Power impact: if the four Lower Snake River dams were breached, Idaho Power would lose use of the lower Snake River water regulation (the dams buffer seasonal flow variability, improving Hells Canyon Complex generation stability by ~10–15%). Idaho Power supports maintaining the Lower Snake River dams and opposes breaching. The Nez Perce Tribe (whose ancestral fishing rights date to the 1855 Walla Walla Treaty) are the most ardent advocates for dam removal.

Irrigation & Agricultural Water Competition

Idaho's hydroelectric system and its irrigated agriculture sector are inextricably linked — and increasingly in tension. The Eastern Snake Plain Aquifer (ESPA) — the largest aquifer in the Pacific Northwest, stretching 10,000 square miles beneath the Snake River Plain — provides water for 3.5 million acres of irrigated land and 430,000 people in southern Idaho. The ESPA is primarily recharged by surface water diversions from the Snake River — meaning drought years that reduce Snake River flows reduce both hydroelectric generation and aquifer recharge. Climate change impact: NRCS and USGS models project 15–30% reduction in Snake River annual flow by 2070 under RCP 8.5 scenarios, driven by reduced Sierra Nevada/Rockies snowpack (shifted from snow to rain, earlier spring runoff). Idaho Power's hydrology challenge: Idaho Power's hydroelectric generation varies dramatically with water year — from ~19 TWh in drought years (e.g., 2021 — the worst Snake River water year since 1977) to ~25 TWh in above-average years (e.g., 2017). This 30% swing in annual generation creates enormous resource adequacy challenges: in drought years Idaho Power must purchase expensive Western spot market power to serve load, dramatically raising customer bills. Idaho Power's 2021 drought: Idaho Power's hydro generation fell ~27% below normal; the company purchased $140M+ of additional power at spot market prices — costs that flowed through to customers as a ~12% rate increase. Idaho's agricultural electricity demand: irrigation pumping is Idaho Power's largest load sector — pumping from the Snake River and ESPA accounts for ~35% of Idaho Power's summer peak demand. Ironically, reduced Snake River flows → less hydropower generated + more pumping required from deeper ESPA wells (more electricity) — a negative feedback loop that climate change will intensify.