Nepaug East Dike
Nepaug East Dike is an earth dam located in Hartford County, Connecticut, built in 1916. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Nepaug East Dike
The primary purpose of Nepaug East Dike 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 Metropolitan District Commission (public utility). It impounds the Nepaug River near Collinsville.
The dam stands 57 feet tall and stretches 700 feet across, creates a reservoir covering 850 acres, has a maximum storage capacity of 40,540 acre-feet, and collects water from a drainage area of 31 square miles. Completed in 1916, the structure is over a century 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 07/27/2023.
At 57 feet, this dam is taller than 95% 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 Connecticut 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 | Connecticut |
| County | Hartford |
| Nearest City | Collinsville |
| River/Stream | Nepaug River |
| Coordinates | 41.82269, -72.93434 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 57 ft |
| Dam Height | 30 ft |
| Dam Length | 700 ft |
| Year Completed | 1916 (110 years old) |
Storage & Hydraulics
| NID Storage | 40,540 acre-ft |
| Max Storage | 40,540 acre-ft |
| Normal Storage | 29,300 acre-ft |
| Surface Area | 850 acres |
| Drainage Area | 31 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Metropolitan District Commission |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/27/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00370 |
| Federal ID | CT00370S03 |
| More Info | State Dam Safety Program |