Magma Retarding

GILA RIVER - TR· Pinal, Arizona· Built 1964· Earth· 21 ft tall
High Hazard Flood Risk Reduction Private

Key Takeaway

Magma Retarding is classified as high hazard in Arizona. It was completed in 1964 and is 62 years old. Its primary use is flood risk reduction. 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 21 ft (taller than 32.9% in AZ)
Dam Length28,900 ft
Dam TypeEarth
Max Storage18.7K acre-ft
Normal Storage0 acre-ft
Surface Area935 acres
Drainage Area62 sq mi
Max Discharge1,000 cfs
Year Completed1964 (62 years old)
NID IDAZ00083

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: December 16, 2019
State Regulated: Yes
Regulatory Agency: ARIZONA DEPARTMENT OF WATER RESOURCES

Ownership

MAGMA FLOOD CONTROL DISTRICT

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Magma Retarding?

Magma Retarding 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 Magma Retarding?

Magma Retarding is owned by MAGMA FLOOD CONTROL DISTRICT (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Magma Retarding built?

Magma Retarding was completed in 1964, making it 62 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 Magma Retarding?

Magma Retarding serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Magma Retarding?

Magma Retarding has a dam height of 21 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 Magma Retarding last inspected?

Magma Retarding was last inspected on December 16, 2019. 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.