Lake Helene Dam

Muddy Branch-TR· Montgomery, Maryland· Built 1950· Earth· 27 ft tall
High Hazard Flood Risk Reduction Local Government

Key Takeaway

Lake Helene Dam is classified as high hazard in Maryland. It was completed in 1950 and is 76 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 27 ft (taller than 67.4% in MD)
Dam Length420 ft
Dam TypeEarth
Max Storage177 acre-ft
Normal Storage1 acre-ft
Surface Area1 acres
Drainage Area0 sq mi
Max Discharge253 cfs
Year Completed1950 (76 years old)
NID IDMD00300

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: March 15, 2023
State Regulated: Yes
Regulatory Agency: MD Dam Safety

Ownership

City of Gaithersburg

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Helene Dam?

Lake Helene Dam 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 Lake Helene Dam?

Lake Helene Dam is owned by City of Gaithersburg (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Helene Dam built?

Lake Helene Dam was completed in 1950, making it 76 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 Lake Helene Dam?

Lake Helene Dam 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 Lake Helene Dam?

Lake Helene Dam has a dam height of 27 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 Lake Helene Dam last inspected?

Lake Helene Dam was last inspected on March 15, 2023. 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.