October Mountain Lake Dam
October Mountain Lake Dam is an earth dam located in Berkshire County, Massachusetts, built in 1972. It carries a High hazard potential classification and has a satisfactory condition assessment.
About October Mountain Lake Dam
The primary purpose of October Mountain Lake Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Ma Department Of Conservation & Recreation (state). It impounds the Tributary Of Mountain Brook near Washington.
The dam stands 39 feet tall and stretches 1,800 feet across, creates a reservoir covering 96 acres, has a maximum storage capacity of 1,930 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1972, the structure is well into its service life at over 50 years old.
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 04/30/2024.
At 39 feet, this dam is taller than 86% of dams nationwide.
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 Massachusetts 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 | Massachusetts |
| County | Berkshire |
| Nearest City | Washington |
| River/Stream | Tributary Of Mountain Brook |
| Coordinates | 42.34729, -73.18798 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 39 ft |
| Dam Length | 1,800 ft |
| Year Completed | 1972 (54 years old) |
Storage & Hydraulics
| NID Storage | 1,930 acre-ft |
| Max Storage | 1,930 acre-ft |
| Normal Storage | 1,130 acre-ft |
| Surface Area | 96 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 190 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | MA Department of Conservation & Recreation |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/30/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA02561 |
| Federal ID | MA02561 |
| More Info | State Dam Safety Program |