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 51–75 of 76
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Post Falls Earth Dike Kootenai County | 16 | 1990 | High | Satisfactory |
| Post Falls South Channel Kootenai County | 25 | 1906 | High | Satisfactory |
| Ravenscroft Diversion Gooding County | 10 | 1983 | Low | Satisfactory |
| Rhead Ranch Elmore County | 34 | 1974 | Low | Satisfactory |
| Rundell Idaho County | 19 | 1975 | Significant | Satisfactory |
| Salmon Falls Creek Twin Falls County | 13 | 1956 | Low | Satisfactory |
| Shoshone Falls Dam 1 Jerome County | 16 | 1907 | Low | Satisfactory |
| Shoshone Falls Dam 2 Jerome County | 16 | 1907 | Low | Satisfactory |
| Shoshone Falls Dam 3 Jerome County | 15 | 1907 | Low | Satisfactory |
| Shoshone Falls Dam 4 Twin Falls County | 18 | 1907 | Low | Satisfactory |
| Simplot Decant Pond Power County | 21 | 2009 | Low | Satisfactory |
| Slack Owyhee County | 20 | 1916 | Low | Satisfactory |
| Smoky Canyon No 2 Caribou County | 108 | 1992 | Significant | Satisfactory |
| Stewart Gulch Main Fork Ada County | 76 | 1998 | Significant | Satisfactory |
| Stewart Gulch North Fork Ada County | 38 | 1997 | Significant | Satisfactory |
| Swan Falls Ada County | 88 | 1901 | High | Satisfactory |
| Thompson Srd Custer County | 77 | 1982 | Significant | Satisfactory |
| Twin Falls Jerome County | 19 | 1935 | Low | Satisfactory |
| Twin Lakes South Franklin County | 36 | 1920 | High | Satisfactory |
| Upper Diversion Dam #1 Bonneville County | 23 | 1982 | Low | Satisfactory |
| Upper Diversion Dam #2 Bonneville County | 33 | 1982 | Low | Satisfactory |
| Upper Salmon Falls A-Plant Diversion Dam Twin Falls County | 9 | 1937 | Low | Satisfactory |
| Upper Salmon Falls A-Plant & Forebay Twin Falls County | 85 | 1937 | Low | Satisfactory |
| Upper Salmon Falls B-Plant Forebay Twin Falls County | 73 | 1947 | Low | Satisfactory |
| W-Drain Gooding County | 17 | 2008 | Significant | Satisfactory |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.