Mansfield Hollow Dam - Dike D and E, also known as Mansfield Hollow Lake, is a Federal-owned structure located in Willimantic, Connecticut.
Wind
Humidity
Built in 1952 by the US Army Corps of Engineers, this gravity dam stands at a height of 78 feet and stretches over 14,050 feet in length. With a primary purpose of flood risk reduction, the dam has a normal storage capacity of 2,800 acre-feet and a maximum storage capacity of 76,000 acre-feet. The dam's spillway, measuring 690 feet wide, is uncontrolled, allowing for the release of excess water to manage water levels and maintain the dam's structural integrity.
The dam's hazard potential is classified as high, with a moderate risk assessment rating of 3. To manage flood risks associated with the dam, the US Army Corps of Engineers conducts regular inspections, maintenance, and repairs to ensure its proper functioning. An Emergency Action Plan (EAP) is in place, meeting guidelines and regularly updated to address potential emergencies. The Corps also collaborates with local emergency managers and the public to raise awareness and support preparedness efforts in case of a dam-related emergency.
Overall, Mansfield Hollow Dam - Dike D and E plays a crucial role in mitigating flood risks in the area, with the US Army Corps of Engineers actively managing and monitoring the dam to ensure its safety and effectiveness. Through ongoing risk assessments, maintenance activities, and community engagement, the Corps continues to prioritize the dam's integrity and the safety of those living downstream.
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
|
257cfs |
Willimantic River Near Coventry
|
157cfs |
Shetucket River Near Willimantic
|
588cfs |
Mount Hope River Near Warrenville
|
30cfs |
Little River Near Hanover
|
34cfs |
Yantic River At Yantic
|
115cfs |
| Location | Reservations | Toilets |
|---|---|---|
Highland Campground
|
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Brialee
|
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Wilderness Lake Campground
|