Dams in Custer County, Idaho

15Total Dams
2High Hazard
4Significant

Dam Safety in Custer County, Idaho

Custer County has 15 dams tracked in the National Inventory of Dams. Of these, 2 are classified as high hazard — meaning failure would probably cause loss of human life. Another 4 carry a significant hazard classification. Currently, 4 dams have a condition assessment of poor or unsatisfactory.

The average dam in Custer County is 63 years old. The most common purpose is other. The tallest dam is Thompson Mtis at 789 ft.

DamHazardConditionHeight (ft)PurposeYear
Thompson MtisHighFair789Tailings1982
MackayHighFair75Other1918
Grouse Creek NorthSignificantSatisfactory110Tailings1994
Thompson SrdSignificantSatisfactory77Water Supply1982
Mosquito FlatSignificantFair58Other1950
Bar DSignificantFair26Irrigation1950
Bradshaw Detention Dam #4LowNot Rated49Flood Risk Reduction1967
Bradshaw Detention Dam #3LowNot Rated33Flood Risk Reduction
South Fork Detention DamLowNot Rated31Flood Risk Reduction
HorseshoeLowNot Rated29Flood Risk Reduction1967
Lehman Creek UpperLowPoor22Other1925
Lehman Creek LowerLowPoor21Recreation1999
SummitLowFair19Irrigation1921
Challis LakeLowPoor19Irrigation1951
Flying Joseph DamLowPoor14Other2008