Lake Mary

Lake Mary is an earth dam located in Mono County, California, built in 1934. It carries a High hazard potential classification.

About Lake Mary

The primary purpose of Lake Mary is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Usda Fs (federal).

The dam stands 10 feet tall and stretches 205 feet across, has a maximum storage capacity of 1,300 acre-feet, and collects water from a drainage area of 7 square miles. Completed in 1934, the structure is well-established, with more than 75 years of service.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 10/24/2013. That was 12 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardNot Rated ConditionEmergency Action Plan: No

Location

StateCalifornia
CountyMono
Nearest CityMammoth Lakes
Coordinates37.60533, -119.00885

Physical Characteristics

Dam TypeEarth
NID Height10 ft
Dam Height10 ft
Dam Length205 ft
Year Completed1934 (92 years old)

Storage & Hydraulics

NID Storage1,300 acre-ft
Max Storage1,300 acre-ft
Normal Storage1,000 acre-ft
Drainage Area7 sq mi
Spillway TypeControlled

Ownership & Safety

PurposeWater Supply
OwnerUSDA FS
Owner TypeFederal
Hazard ClassificationHigh
Condition AssessmentNot Rated
Last Inspection10/24/2013
Emergency Action PlanNo

Identifiers

NID IDCA10388
Federal IDCA10388
More InfoState Dam Safety Program

Nearby Dams