Little Cohas Brook Dam
Little Cohas Brook Dam is a concrete dam located in Rockingham County, New Hampshire, built in 1953. It carries a Low hazard potential classification and has a satisfactory condition assessment.
About Little Cohas Brook Dam
The primary purpose of Little Cohas Brook Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Nh Dot (state). It impounds the Little Cohas Brook near Londonderry.
The dam stands 10 feet tall and stretches 70 feet across, creates a reservoir covering 17 acres, has a maximum storage capacity of 867 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1953, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 10/17/2022.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New Hampshire |
| County | Rockingham |
| Nearest City | Londonderry |
| River/Stream | Little Cohas Brook |
| Coordinates | 42.91770, -71.41690 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 10 ft |
| Dam Height | 10 ft |
| Dam Length | 70 ft |
| Year Completed | 1953 (73 years old) |
Storage & Hydraulics
| NID Storage | 867 acre-ft |
| Max Storage | 867 acre-ft |
| Normal Storage | 39 acre-ft |
| Surface Area | 17 acres |
| Drainage Area | 6 sq mi |
| Max Discharge | 1,011 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | NH DOT |
| Owner Type | State |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/17/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NH00509 |
| Federal ID | NH00509 |
| More Info | State Dam Safety Program |