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 26–50 of 395
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Twin Lakes Kootenai County | 14 | 2005 | Significant | Fair |
| Twin Granite Adams County | 25 | 1920 | Low | Fair |
| Twin Falls Jerome County | 19 | 1935 | Low | Satisfactory |
| Twenty Four Mile Caribou County | 27 | 1928 | Significant | Fair |
| Trail Diversion Elmore County | 28 | 1962 | Low | Fair |
| Trail Creek Dam Blaine County | 23 | 1937 | High | Fair |
| Trail Elmore County | 30 | 1960 | Significant | Fair |
| Toponce Ditch Dam Lower Caribou County | 18 | — | Low | Fair |
| Tom J Dike Valley County | 27 | 1995 | Significant | Fair |
| Tom J Valley County | 57 | 1995 | Significant | Fair |
| Tingey Franklin County | 25 | 1955 | Low | Fair |
| Tindall Owyhee County | 13 | 1951 | Low | Fair |
| Thorn Creek Dam Gooding County | 22 | — | Low | Not Rated |
| Thompson Srd Custer County | 77 | 1982 | Significant | Satisfactory |
| Thompson No 2 Clearwater County | 19 | 1970 | Significant | Fair |
| Thompson No 1 Main Dam Nez Perce County | 17 | 1967 | Significant | Fair |
| Thompson Mtis Custer County | 789 | 1982 | High | Fair |
| Texas Basin Owyhee County | 121 | 1979 | High | Fair |
| Teapot Upper Elmore County | 28 | 1977 | Significant | Poor |
| Teapot Lower Elmore County | 32 | 1977 | Significant | Fair |
| Taylor Upper Owyhee County | 18 | 1964 | Significant | Fair |
| Taylor Lower Owyhee County | 18 | 1965 | Significant | Fair |
| Swan Falls Ada County | 88 | 1901 | High | Satisfactory |
| Surmeier Payette County | 32 | 1978 | Significant | Fair |
| Sunshine No 2 Shoshone County | 54 | — | Significant | Fair |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.