Upper Lake Mary

WALNUT CREEK· Coconino, Arizona· Built 1941· Earth· 38 ft tall
Significant Hazard Recreation Water Supply Local Government

Key Takeaway

Upper Lake Mary is classified as significant hazard in Arizona. It was completed in 1941 and is 85 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 38 ft (taller than 66.8% in AZ)
Dam Length845 ft
Dam TypeEarth
Max Storage21.0K acre-ft
Normal Storage16.6K acre-ft
Surface Area1,058 acres
Drainage Area54 sq mi
Max Discharge11,000 cfs
Year Completed1941 (85 years old)
NID IDAZ00016

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: June 26, 2018
State Regulated: Yes
Regulatory Agency: ARIZONA DEPARTMENT OF WATER RESOURCES

Ownership

CITY OF FLAGSTAFF

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper Lake Mary?

Upper Lake Mary is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Upper Lake Mary?

Upper Lake Mary is owned by CITY OF FLAGSTAFF (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Upper Lake Mary built?

Upper Lake Mary was completed in 1941, making it 85 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 Upper Lake Mary?

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

How tall is Upper Lake Mary?

Upper Lake Mary has a dam height of 38 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 Upper Lake Mary last inspected?

Upper Lake Mary was last inspected on June 26, 2018. 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.