Castle

Castle is an earth dam located in Merced County, California, built in 1991. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Castle

The primary purpose of Castle 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 County Of Merced (local government). It impounds the Canal Creek near Merced.

The dam stands 40 feet tall and stretches 2,027 feet across, creates a reservoir covering 1,280 acres, has a maximum storage capacity of 7,510 acre-feet, and collects water from a drainage area of 28 square miles. Completed in 1991, the structure is 35 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. 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 03/24/2025.

At 40 feet, this dam is taller than 87% of dams nationwide.

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
CountyMerced
Nearest CityMerced
River/StreamCanal Creek
Coordinates37.40420, -120.54620

Physical Characteristics

Dam TypeEarth
NID Height40 ft
Dam Height40 ft
Dam Length2,027 ft
Year Completed1991 (35 years old)

Storage & Hydraulics

NID Storage7,510 acre-ft
Max Storage7,510 acre-ft
Surface Area1,280 acres
Drainage Area28 sq mi

Ownership & Safety

PurposeFlood Risk Reduction
OwnerCounty of Merced
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection03/24/2025
Emergency Action PlanYes

Identifiers

NID IDCA01355
Federal IDCA01355
More InfoState Dam Safety Program

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