Blackwater Dam, also known as Dry Reservoir, is a gravity-type dam located on the Blackwater River in Webster, New Hampshire.
Wind
Humidity
Built in 1941 by the US Army Corps of Engineers, the dam stands at a height of 75 feet and has a maximum storage capacity of 93,400 acre-feet. Its primary purpose is flood risk reduction, with a spillway width of 241 feet to manage water levels during periods of high discharge.
The dam is associated with two other structures and is owned, funded, designed, and regulated by the US Army Corps of Engineers. It has a high hazard potential and is subject to regular inspections and emergency action plans. USACE actively manages dam-related flood risks by monitoring its condition, prioritizing risk-reducing activities, and collaborating with local emergency managers to ensure preparedness and response in case of an emergency.
With a drainage area of 128 square miles and a moderate risk assessment score, Blackwater Dam plays a crucial role in water resource management in Merrimack, New Hampshire. As climate change continues to impact water resource availability and extreme weather events, the dam's role in flood risk reduction and water management becomes increasingly vital for ensuring the safety and resilience of the surrounding communities.
Year Completed |
1941 |
Dam Length |
1150 |
Dam Height |
75 |
River Or Stream |
BLACKWATER RIVER |
Primary Dam Type |
Gravity |
Surface Area |
1 |
Hydraulic Height |
64 |
Drainage Area |
128 |
Nid Storage |
93400 |
Structural Height |
69 |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
75 |