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 326–350 of 395
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Spencer Idaho County | 15 | 1954 | Significant | Fair |
| Spencer Owyhee County | 23 | 1939 | Significant | Fair |
| Spring Creek Camas County | 17 | 1918 | Low | Fair |
| Springfeild Bird Haven Bingham County | 13 | — | Low | Poor |
| Spring Valley Latah County | 47 | 1962 | High | Fair |
| Squaw Creek Owyhee County | 61 | 1968 | High | Fair |
| Stanislaw Lake Blaine County | 13 | 1997 | Significant | Fair |
| Star No 6 Shoshone County | 33 | 1979 | High | Fair |
| Stewart Gulch Main Fork Ada County | 76 | 1998 | Significant | Satisfactory |
| Stewart Gulch North Fork Ada County | 38 | 1997 | Significant | Satisfactory |
| Stewart Ranch Caribou County | 15 | 1965 | Low | Fair |
| Stoneridge Bonner County | 28 | 1969 | Significant | Fair |
| Strickland Owyhee County | 35 | 1927 | Low | Fair |
| Strong Arm No 1 (Upper) Franklin County | 39 | 1887 | High | Fair |
| Strong Arm No 2 (Lower) Franklin County | 27 | 1897 | Significant | Poor |
| Sublett Cassia County | 48 | 1914 | High | Fair |
| Sulphur Gulch Payette County | 23 | 1976 | Low | Fair |
| Summit Camas County | 13 | 1941 | Low | Fair |
| Summit Custer County | 19 | 1921 | Low | Fair |
| Sunset Palisades Nez Perce County | 41 | 1973 | Significant | Fair |
| Sunshine No 2 Shoshone County | 54 | — | Significant | Fair |
| Surmeier Payette County | 32 | 1978 | Significant | Fair |
| Swan Falls Ada County | 88 | 1901 | High | Satisfactory |
| Taylor Lower Owyhee County | 18 | 1965 | Significant | Fair |
| Taylor Upper Owyhee County | 18 | 1964 | Significant | Fair |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.