Lower Lake Mary

WALNUT CANYON· Coconino, Arizona· Built 1907· Earth· 33 ft tall
High Hazard Water Supply Fish And Wildlife Pond Recreation Federal Government

Key Takeaway

Lower Lake Mary is classified as high hazard in Arizona. It was completed in 1907 and is 119 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 33 ft (taller than 59.3% in AZ)
Dam Length650 ft
Dam TypeEarth
Max Storage22.4K acre-ft
Normal Storage11.0K acre-ft
Surface Area910 acres
Drainage Area27 sq mi
Max Discharge3,298 cfs
Year Completed1907 (119 years old)
NID IDAZ00015

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: September 10, 2020
State Regulated: No

Ownership

USDA FS

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lower Lake Mary?

Lower Lake Mary 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 Lower Lake Mary?

Lower Lake Mary is owned by USDA FS (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lower Lake Mary built?

Lower Lake Mary was completed in 1907, making it 119 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 Lower Lake Mary?

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

How tall is Lower Lake Mary?

Lower Lake Mary has a dam height of 33 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 Lower Lake Mary last inspected?

Lower Lake Mary was last inspected on September 10, 2020. 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.