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 76–100 of 141
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Idc-Effluent Storage Ada County | 23 | 1998 | Significant | Satisfactory |
| Hulet No 2 Dam Owyhee County | 55 | 1987 | Significant | Fair |
| Hughes Valley County | 43 | 1957 | Significant | Fair |
| Hot Springs No 3 Elmore County | 28 | 1984 | Significant | Fair |
| Horsethief Valley County | 53 | 1967 | Significant | Fair |
| Hornet Creek Upper South Washington County | 19 | 1913 | Significant | Fair |
| Hornet Creek Upper North Washington County | 21 | 1913 | Significant | Fair |
| 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 |
| Hawkins Bannock County | 35 | 1870 | Significant | Fair |
| Haw Creek Gem County | 27 | 1970 | Significant | Fair |
| Hardisty Owyhee County | 31 | 1914 | Significant | Fair |
| Hansen Latah County | 18 | 1976 | Significant | Satisfactory |
| Hancock Adams County | 29 | 1931 | Significant | Fair |
| Hammond Bear Lake County | 33 | 1933 | Significant | Fair |
| Hall Elmore County | 33 | 1945 | Significant | Poor |
| Grouse Creek North Custer County | 110 | 1994 | Significant | Satisfactory |
| Grasmere North Dam Owyhee County | 22 | 1936 | Significant | Poor |
| Grasmere East Dam Owyhee County | 11 | — | Significant | Poor |
| Granite Lake Valley County | 25 | 1949 | Significant | Fair |
| Gimlet Blaine County | 24 | 1987 | Significant | Fair |
| Gatfield No 2 Gem County | 20 | 1951 | Significant | Fair |
| Gatfield No 1 Gem County | 16 | 1938 | Significant | Fair |
| Galena No 2 Mtis Shoshone County | 48 | — | Significant | Fair |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.