Cook Reservoir

UNKNOWN· Graham, Arizona· Built 1940· Earth· 18 ft tall
High Hazard Water Supply State Government

Key Takeaway

Cook Reservoir is classified as high hazard in Arizona. It was completed in 1940 and is 86 years old. Its primary use is water supply. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 18 ft (taller than 25.1% in AZ)
Dam Length450 ft
Dam TypeEarth
Max Storage59 acre-ft
Normal Storage0 acre-ft
Surface Area17 acres
Drainage Area1 sq mi
Year Completed1940 (86 years old)
NID IDAZ00245

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: January 14, 2021
State Regulated: Yes
Regulatory Agency: ARIZONA DEPARTMENT OF WATER RESOURCES

Ownership

EASTERN ARIZONA COLLEGE

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Cook Reservoir?

Cook Reservoir is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Cook Reservoir?

Cook Reservoir is owned by EASTERN ARIZONA COLLEGE (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Cook Reservoir built?

Cook Reservoir was completed in 1940, making it 86 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Cook Reservoir?

Cook Reservoir serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Cook Reservoir?

Cook Reservoir has a dam height of 18 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Cook Reservoir last inspected?

Cook Reservoir was last inspected on January 14, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.