Cohas Avenue Dam
Key Takeaway
Cohas Avenue Dam is classified as low hazard in New Hampshire. It was completed in 1874 and is 152 years old. Its primary use is water supply.
Physical Details
| Dam Height | 20 ft (taller than 70.9% in NH) |
| Dam Length | 1,000 ft |
| Dam Type | Earth |
| Max Storage | 61 acre-ft |
| Normal Storage | 49 acre-ft |
| Surface Area | 3 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1874 (152 years old) |
| NID ID | NH00771 |
Safety Information
No probable loss of human life and low economic/environmental losses expected.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
MANCHESTER WATER WORKS
Local Government
Nearby Dams
Massabesic Lake Dam
Hillsborough, NH
High Hazard 30 ftPine Island Pond Dam
Hillsborough, NH
Low Hazard 19 ftManchester Airport Det Pond Dam
Rockingham, NH
Low Hazard 27 ftDorrs Pond Dam
Hillsborough, NH
High Hazard 9 ftLittle Cohas Brook Dam
Rockingham, NH
Low Hazard 10 ftGoldfish Pond Dam
Merrimack, NH
Low Hazard 16 ftWoodbury Estate Pond Dam
Hillsborough, NH
Significant Hazard 16 ftAmoskeag
Hillsborough, NH
High Hazard 29 ftFrequently Asked Questions
What is the hazard classification of Cohas Avenue Dam?
Cohas Avenue Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Cohas Avenue Dam?
Cohas Avenue Dam is owned by MANCHESTER WATER WORKS (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Cohas Avenue Dam built?
Cohas Avenue Dam was completed in 1874, making it 152 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Cohas Avenue Dam?
Cohas Avenue Dam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Cohas Avenue Dam?
Cohas Avenue Dam has a dam height of 20 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was Cohas Avenue Dam last inspected?
Cohas Avenue Dam was last inspected on October 8, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.