Cobble Mountain Reservoir Dam
Cobble Mountain Reservoir Dam is an earth dam located in Hampden County, Massachusetts, built in 1930. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Cobble Mountain Reservoir Dam
The primary purpose of Cobble Mountain Reservoir Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Springfield Water And Sewer Commission (local government). It impounds the Little River near Russell.
The dam stands 245 feet tall and stretches 730 feet across, creates a reservoir covering 1,150 acres, has a maximum storage capacity of 97,200 acre-feet, and collects water from a drainage area of 45 square miles. Completed in 1930, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 11/14/2023.
At 245 feet, this dam is taller than 99% of all dams in the United States.
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 | Hampden |
| Nearest City | Russell |
| River/Stream | Little River |
| Coordinates | 42.12203, -72.89163 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 245 ft |
| Dam Length | 730 ft |
| Year Completed | 1930 (96 years old) |
Storage & Hydraulics
| NID Storage | 97,200 acre-ft |
| Max Storage | 97,200 acre-ft |
| Normal Storage | 72,930 acre-ft |
| Surface Area | 1,150 acres |
| Drainage Area | 45 sq mi |
| Max Discharge | 33,540 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Springfield Water and Sewer Commission |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/14/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00068 |
| Federal ID | MA00068 |
| More Info | State Dam Safety Program |