Lake Helene Dam
Lake Helene Dam is an earth dam located in Montgomery County, Maryland, built in 1950. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Helene Dam
The primary purpose of Lake Helene Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Gaithersburg (local government). It impounds the Muddy Branch-tr near Gaithersburg.
The dam stands 27 feet tall and stretches 420 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 177 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1950, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 04/18/2024.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Maryland dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Maryland |
| County | Montgomery |
| Nearest City | Gaithersburg |
| River/Stream | Muddy Branch-tr |
| Coordinates | 39.11933, -77.24070 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 27 ft |
| Dam Height | 27 ft |
| Dam Length | 420 ft |
| Year Completed | 1950 (76 years old) |
Storage & Hydraulics
| NID Storage | 177 acre-ft |
| Max Storage | 177 acre-ft |
| Normal Storage | 1 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 253 cfs |
| Spillway Type | None |
Ownership & Safety
| Purpose | Recreation |
| Owner | City of Gaithersburg |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/18/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | MD00325 |
| Federal ID | MD00325 |
| More Info | State Dam Safety Program |