Idaho Dams
395 dams tracked by the National Inventory of Dams
Total Dams
395
High Hazard
97
24.6%
Poor / Unsatisfactory
42
Average Age
76 yrs
Hazard Classification
High97 (24.6%)
Significant141 (35.7%)
Low156 (39.5%)
Condition Assessment
Satisfactory76 (19.2%)
Fair248 (62.8%)
Poor / Unsatisfactory42 (10.6%)
Not Rated29 (7.3%)
Federal
33
State
14
Local
18
Private
325
Tallest Dams
- Thompson Mtis789 ft
- Dworshak Dam717 ft
- Anderson Ranch Dam456 ft
- Arrowrock Dam350 ft
- Lucky Peak Dam340 ft
High Hazard Dams
- Thompson MtisHigh
- Dworshak DamHigh
- Anderson Ranch DamHigh
- Arrowrock DamHigh
- Lucky Peak DamHigh
Poor Condition Dams
- Magic DamUnsatisfactory
- Fish CreekPoor
- OrchardPoor
- Saint JohnUnsatisfactory
- Louisa CreekPoor
All Dams in Idaho
Showing 226–250 of 395
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Hulet No 2 Dike Owyhee County | 13 | 1987 | Low | Poor |
| Hulet No 2 Dam Owyhee County | 55 | 1987 | Significant | Fair |
| Hulet Owyhee County | 99 | 1976 | High | Fair |
| Hughes Valley County | 43 | 1957 | Significant | Fair |
| Hubbard Dam Ada County | 23 | 1902 | Low | Not Available |
| Hot Springs No 3 Elmore County | 28 | 1984 | Significant | Fair |
| Hot Springs No 2 Elmore County | 41 | 1968 | High | Fair |
| Horsethief Valley County | 53 | 1967 | Significant | Fair |
| Horseshoe Bend Diversion Boise County | 8 | 1995 | Low | Fair |
| Horseshoe Custer County | 29 | 1967 | Low | Not Rated |
| Hornet Creek Upper South Washington County | 19 | 1913 | Significant | Fair |
| Hornet Creek Upper North Washington County | 21 | 1913 | Significant | Fair |
| Hornet Creek Lower Washington County | 26 | 1913 | Low | Fair |
| Hollenbeak Valley County | 29 | 1972 | Low | Fair |
| Holbrook Valley County | 17 | 1955 | Low | Satisfactory |
| Hidden Springs Cell 3a Ada County | 43 | 2007 | Significant | Satisfactory |
| Hidden Lake Valley County | 26 | 1970 | Significant | Fair |
| Herrick Valley County | 38 | 1953 | Significant | Fair |
| Henrys Lake Fremont County | 25 | 1923 | High | Fair |
| Henrys Fork Ranch Fremont County | 23 | 1987 | Low | Fair |
| Hells Canyon Adams County | 330 | 1967 | High | Satisfactory |
| Heil No 1 Twin Falls County | 24 | 1974 | Low | Fair |
| Hayden Lake Kootenai County | 13 | 1910 | Low | Fair |
| Hawkins Bannock County | 35 | 1870 | Significant | Fair |
| Haw Creek Gem County | 27 | 1970 | Significant | Fair |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.