Basin accounting
Idaho's water basins
Reporting districts roll up to nine basins. Each basin has its own adjudication status, hydrology, and management challenges. Click any basin for the full drill-down.
Basins managed
9
PODs statewide
10,801
2024 volume
8.43M AF
Rights tracked
16,794
Eastern Snake Plain Aquifer
One of the largest aquifers in North America. Conjunctively managed with surface flows on the Snake. Subject of the 2015 SWC settlement and the 2024 curtailment order.
PODs
4,678
2024 volume
1,884K AF
Rights
7,397
Reporting rate
81%
Upper Snake (above Milner Dam)
Mainstem Snake River and tributaries from Wyoming border to Milner. Includes Henrys Fork, Teton, and South Fork.
PODs
3,227
2024 volume
1,803K AF
Rights
4,637
Reporting rate
62%
Middle Snake / Magic Valley reach
Milner to Hells Canyon. Spring-fed reaches at Thousand Springs, hydropower constraints, and the 1994 Swan Falls agreement.
PODs
550
2024 volume
3,365K AF
Rights
1,025
Reporting rate
32%
Bear River
Tri-state compact (ID/UT/WY). Includes Malad and Bear Lake systems.
PODs
293
2024 volume
561K AF
Rights
325
Reporting rate
46%
Big Wood / Lost River systems
Mostly closed basins; includes Big Wood, Little Wood, Lost River, Camas. Subject of ongoing GWMA studies.
PODs
1,144
2024 volume
120K AF
Rights
1,748
Reporting rate
57%
Boise / Payette / Owyhee
Treasure Valley demand and high-growth area. Owyhee feeds the Owyhee Project (multi-state).
PODs
592
2024 volume
191K AF
Rights
994
Reporting rate
69%
Salmon / Lemhi
Anadromous-fish habitat. Listed steelhead and Chinook stocks. Lemhi MOU and basin recovery plan.
PODs
32
2024 volume
0K AF
Rights
90
Reporting rate
0%
Lower Snake / Hells Canyon
Below Hells Canyon Dam. Idaho Power license conditions and FERC compliance.
PODs
135
2024 volume
501K AF
Rights
477
Reporting rate
93%
IDWR-administered
PODs administered directly by IDWR (special / cross-basin / state-owned).
PODs
150
2024 volume
6K AF
Rights
101
Reporting rate
23%
Strategic plan FY26-29
Basin accounting models
IDWR's strategic plan calls for "developing basin accounting models" that link surface flows, groundwater pumping, and replacement water in a single ledger. WMIS NextGen's basin view stitches together POD measurements (10,801 statewide), water rights (16,794 tracked), mitigation plans (14 active and pending), and curtailment orders — basin by basin.