Mansfield Hollow Dam - Dike A and B, also known as Mansfield Hollow Lake, is a federal-owned structure located in Willimantic, Connecticut.
Wind
Humidity
Constructed in 1952 by the US Army Corps of Engineers, this gravity dam stands at a height of 78 feet and has a hydraulic height of 74 feet. With a dam volume of 1,458,000 cubic feet and a storage capacity of 76,000 acre-feet, it primarily serves the purpose of flood risk reduction along the Nachaug River.
Managed by the US Army Corps of Engineers, Mansfield Hollow Dam plays a crucial role in mitigating flood risks in the region by monitoring its structural health, conducting regular inspections, and engaging with local emergency managers to ensure preparedness in case of dam-related emergencies. The dam has a high hazard potential and a moderate risk assessment level, highlighting the importance of ongoing risk management measures to safeguard the surrounding communities and infrastructure. While the dam is equipped with an uncontrolled spillway and emergency action plan, efforts are continuously made to address potential flood risks and enhance public safety.
Despite its critical role in flood control, Mansfield Hollow Dam is not immune to the unpredictable nature of severe weather events and the inherent limitations of water storage capacity. As such, the US Army Corps of Engineers remains vigilant in its risk management approach, constantly working to address evolving threats and ensure the structural integrity of the dam. By collaborating with local stakeholders, maintaining emergency preparedness, and conducting necessary maintenance and repairs, the USACE strives to uphold the safety and resilience of Mansfield Hollow Dam for the benefit of the surrounding communities and environment.
Year Completed |
1952 |
Dam Length |
14050 |
Dam Height |
78 |
River Or Stream |
NACHAUG RIVER |
Primary Dam Type |
Gravity |
Surface Area |
450 |
Hydraulic Height |
74 |
Drainage Area |
159 |
Nid Storage |
76000 |
Structural Height |
78 |
Hazard Potential |
High |
Nid Height |
78 |
Natchaug River At Willimantic
|
322cfs |
Willimantic River Near Coventry
|
189cfs |
Shetucket River Near Willimantic
|
777cfs |
Mount Hope River Near Warrenville
|
32cfs |
Little River Near Hanover
|
44cfs |
Yantic River At Yantic
|
147cfs |
| Location | Reservations | Toilets |
|---|---|---|
Highland Campground
|
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Brialee
|
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Wilderness Lake Campground
|