Farmington Dam

Farmington Dam is an earth dam located in San Joaquin County, California, built in 1951. It carries a High hazard potential classification.

About Farmington Dam

The primary purpose of Farmington Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Usace - Sacramento District (federal). It impounds the Rock And Littlejohn Creeks near Farmington.

The dam stands 58 feet tall and stretches 7,800 feet across, creates a reservoir covering 4,100 acres, has a maximum storage capacity of 119,314 acre-feet, and collects water from a drainage area of 212 square miles. Completed in 1951, the structure is well into its service life at over 50 years 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. An emergency action plan is in place for this dam. The most recent inspection on record was 07/14/2025.

At 58 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 HazardNot Available ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountySan Joaquin
Nearest CityFarmington
River/StreamRock And Littlejohn Creeks
Coordinates37.90680, -120.93406

Physical Characteristics

Dam TypeEarth
NID Height58 ft
Dam Height58 ft
Dam Length7,800 ft
Year Completed1951 (75 years old)

Storage & Hydraulics

NID Storage119,314 acre-ft
Max Storage119,314 acre-ft
Normal Storage6,623 acre-ft
Surface Area4,100 acres
Drainage Area212 sq mi
Max Discharge12,600 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeFlood Risk Reduction
OwnerUSACE - Sacramento District
Owner TypeFederal
Hazard ClassificationHigh
Condition AssessmentNot Available
Last Inspection07/14/2025
Emergency Action PlanYes

Identifiers

NID IDCA10104
Federal IDCA10104
More InfoState Dam Safety Program

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