Northwood Lake Dam
Northwood Lake Dam is a concrete dam located in Merrimack County, New Hampshire, built in 1926. It carries a High hazard potential classification and has a poor condition assessment.
About Northwood Lake Dam
The primary purpose of Northwood Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Nh Des Water Division (state). It impounds the Little Suncook River near Epsom.
The dam stands 13 feet tall and stretches 169 feet across, creates a reservoir covering 665 acres, has a maximum storage capacity of 3,200 acre-feet, and collects water from a drainage area of 23 square miles. Completed in 1926, 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 08/31/2021.
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 New Hampshire 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 | New Hampshire |
| County | Merrimack |
| Nearest City | Epsom |
| River/Stream | Little Suncook River |
| Coordinates | 43.21979, -71.29063 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 13 ft |
| Dam Height | 13 ft |
| Dam Length | 169 ft |
| Year Completed | 1926 (100 years old) |
Storage & Hydraulics
| NID Storage | 3,200 acre-ft |
| Max Storage | 3,200 acre-ft |
| Normal Storage | 2,100 acre-ft |
| Surface Area | 665 acres |
| Drainage Area | 23 sq mi |
| Max Discharge | 1,629 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | NH DES WATER DIVISION |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 08/31/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NH00285 |
| Federal ID | NH00285 |
| More Info | State Dam Safety Program |