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 301–325 of 395
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Shiner Upper Lemhi County | 29 | 1968 | Significant | Fair |
| Shoofly Owyhee County | 46 | 1977 | Low | Fair |
| 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 |
| Silver Lake Fremont County | 13 | 1915 | Significant | Fair |
| Simplot Decant Pond Power County | 21 | 2009 | Low | Satisfactory |
| Simplot Effluent Irrigation Lagoon Bannock County | 39 | 1981 | High | Fair |
| Sirucek Reservoir Jerome County | 17 | 2003 | Low | Poor |
| Slack Owyhee County | 20 | 1916 | Low | Satisfactory |
| Smalley Valley County | 35 | 1952 | Low | Fair |
| Smoky Canyon No 1 Caribou County | 80 | 1983 | Low | Fair |
| Smoky Canyon No 2 Caribou County | 108 | 1992 | Significant | Satisfactory |
| Snow Creek North Owyhee County | 13 | 1957 | Low | Fair |
| Snow Creek South Owyhee County | 11 | 1957 | Low | Fair |
| Soda Caribou County | 103 | 1925 | High | Fair |
| Soda Creek Dike Caribou County | 16 | 1967 | Low | Fair |
| Soda Creek Main Dam Caribou County | 36 | 1967 | High | Fair |
| Soldiers Meadow Dam Nez Perce County | 69 | 1922 | High | Not Available |
| Sommerville Owyhee County | 29 | 1926 | Low | Fair |
| Soulen Auxiliary Dike Washington County | 7 | 1935 | Low | Fair |
| Soulen Family Dam Valley County | 22 | 2009 | Low | Fair |
| Soulen Main Dam Washington County | 18 | 1935 | Significant | Fair |
| South Fork Detention Dam Custer County | 31 | — | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.