Dams in Mono County, California

20Total Dams
14High Hazard
1Significant

Dam Safety in Mono County, California

Mono County has 20 dams tracked in the National Inventory of Dams. Of these, 14 are classified as high hazard — meaning failure would probably cause loss of human life. Another 1 carry a significant hazard classification. Currently, 4 dams have a condition assessment of poor or unsatisfactory.

The average dam in Mono County is 100 years old. The most common purpose is water supply. The tallest dam is Long Valley at 126 ft.

DamHazardConditionHeight (ft)PurposeYear
Long ValleyHighSatisfactory126Water Supply1941
Grant LakeHighPoor87Water Supply1940
Gem LakeHighPoor80Hydroelectric1917
BridgeportHighSatisfactory63Water Supply1924
Rush MeadowsHighPoor50Hydroelectric1925
Lundy LakeHighSatisfactory48Hydroelectric1911
Saddlebag LakeHighSatisfactory45Hydroelectric1921
Agnew LakeHighPoor30Hydroelectric1916
Tioga Lake AuxiliaryHighSatisfactory19Hydroelectric1928
RhinedollarHighSatisfactory18Hydroelectric1927
Ler Twin LakeHighFair16Water Supply1888
Upper Twin LakeHighFair14Water Supply1905
Topaz LakeHighSatisfactory11Flood Risk Reduction1937
Lake MaryHighNot Rated10Water Supply1934
Lake MamieSignificantNot Rated6Water Supply1968
Upper GorgeLowSatisfactory44Other1953
Lobdel LakeLowSatisfactory27Water Supply1948
Poore Lake ReservoirLowSatisfactory23Water Supply1900
Black ReservoirLowSatisfactory18Water Supply1905
Walker LakeLowSatisfactory12Water Supply