Headgate Rock

Headgate Rock is an earth dam located in La Paz County, Arizona, built in 1941. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Headgate Rock

The primary purpose of Headgate Rock is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bia (federal). It impounds the Colorado River near Parker.

The dam stands 70 feet tall and stretches 1,975 feet across, creates a reservoir covering 768 acres, has a maximum storage capacity of 29,485 acre-feet, and collects water from a drainage area of 239 square miles. Completed in 1941, 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. 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 11/30/2021.

At 70 feet, this dam is taller than 96% 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 Arizona 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

StateArizona
CountyLa Paz
Nearest CityParker
River/StreamColorado River
Coordinates34.16850, -114.27730

Physical Characteristics

Dam TypeEarth
NID Height70 ft
Dam Height45 ft
Dam Length1,975 ft
Year Completed1941 (85 years old)

Storage & Hydraulics

NID Storage29,485 acre-ft
Max Storage29,485 acre-ft
Normal Storage7,025 acre-ft
Surface Area768 acres
Drainage Area239 sq mi
Max Discharge140,000 cfs
Spillway TypeControlled

Ownership & Safety

PurposeIrrigation
OwnerBIA
Owner TypeFederal
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection11/30/2021
Emergency Action PlanYes

Identifiers

NID IDAZ10437
Federal IDAZ10437
More InfoState Dam Safety Program

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