Lake Marie

Lake Marie is an earth dam located in Napa County, California, built in 1908. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Lake Marie

The primary purpose of Lake Marie 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 County Of Napa (local government). It impounds the Tr Tulucay Cr near Napa.

The dam stands 60 feet tall and stretches 454 feet across, creates a reservoir covering 8 acres, has a maximum storage capacity of 170 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1908, the structure is over a century old.

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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 10/15/2024.

At 60 feet, this dam is taller than 95% of all dams in the United States.

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 HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountyNapa
Nearest CityNapa
River/StreamTr Tulucay Cr
Coordinates38.25980, -122.22930

Physical Characteristics

Dam TypeEarth
NID Height60 ft
Dam Height60 ft
Dam Length454 ft
Year Completed1908 (118 years old)

Storage & Hydraulics

NID Storage170 acre-ft
Max Storage170 acre-ft
Surface Area8 acres
Drainage Area1 sq mi

Ownership & Safety

PurposeWater Supply
OwnerCounty of Napa
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection10/15/2024
Emergency Action PlanYes

Identifiers

NID IDCA00004
Federal IDCA00004
More InfoState Dam Safety Program

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