Mountain Lake Dam
Mountain Lake Dam is an earth dam located in Morris County, New Jersey. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Mountain Lake Dam
The primary purpose of Mountain Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Mountain Lakes Borough (local government). It impounds the Troy Brook near Parsippany.
The dam stands 15 feet tall and stretches 100 feet across, creates a reservoir covering 76 acres, has a maximum storage capacity of 1,060 acre-feet, and collects water from a drainage area of 1 square miles.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 12/06/2024.
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 New Jersey 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 | New Jersey |
| County | Morris |
| Nearest City | Parsippany |
| River/Stream | Troy Brook |
| Coordinates | 40.88403, -74.44513 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 100 ft |
Storage & Hydraulics
| NID Storage | 1,060 acre-ft |
| Max Storage | 1,060 acre-ft |
| Normal Storage | 760 acre-ft |
| Surface Area | 76 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 79 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Mountain Lakes Borough |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/06/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00284 |
| Federal ID | NJ00284 |
| More Info | State Dam Safety Program |