Tyler Dam
Tyler Dam is an earth dam located in Middlesex County, Massachusetts, built in 1965. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Tyler Dam
The primary purpose of Tyler 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 Assabet River near Marlborough.
The dam stands 34 feet tall and stretches 1,400 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 5,500 acre-feet, and collects water from a drainage area of 38 square miles. Completed in 1965, 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 04/04/2023.
At 34 feet, this dam is taller than 80% 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 | Middlesex |
| Nearest City | Marlborough |
| River/Stream | Assabet River |
| Coordinates | 42.34578, -71.61401 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Length | 1,400 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 5,500 acre-ft |
| Max Storage | 5,500 acre-ft |
| Normal Storage | 10 acre-ft |
| Surface Area | 2 acres |
| Drainage Area | 38 sq mi |
| Max Discharge | 900 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 | 04/04/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA01195 |
| Federal ID | MA01195 |
| More Info | State Dam Safety Program |