Idaho has 3 high hazard dams with a condition assessment of poor or unsatisfactory. These are dams where failure would probably cause loss of human life and where recognized safety deficiencies have been identified.
Of the 96 high hazard dams in Idaho, 3 (3%) have concerning condition ratings — 2 rated poor and 1 rated unsatisfactory.
Condition scale, best to worst
- Satisfactory No existing or potential safety deficiencies recognized; acceptable performance expected under all loading conditions.
- Fair No deficiencies under normal operating conditions; a rare flood or earthquake could create one.
- Poor A safety deficiency is recognized under normal operating conditions; remedial action is necessary.
- Unsatisfactory Worst rating. The dam is considered unsafe; a deficiency requires immediate or emergency remedial action.
"Not rated" means no assessment is on file in the National Inventory of Dams.
| Dam | County | Height (ft) | Condition | Last inspected | Purpose | Year |
|---|---|---|---|---|---|---|
| Fish Creek | Blaine | 92 | Poor | 10/29/20196 yrs ago | Irrigation | 1923 |
| Saint John | Oneida | 43 | Unsatisfactory | 04/23/20197 yrs ago | Irrigation | 1918 |
| Lost Valley | Adams | 31 | Poor | 06/18/20197 yrs ago | Other | 1910 |