Surry Mountain Dam, also known as Surry Mountain Lake, is a rockfill dam located in Cheshire County, New Hampshire.
Wind
Humidity
Built in 1941 by the US Army Corps of Engineers, the dam stands at a height of 83 feet and has a maximum storage capacity of 44,000 acre-feet. Its primary purpose is flood risk reduction, protecting downstream communities along the Ashuelot River, such as Keene, Swanzey, Winchester, and Hinsdale, from potential flooding events.
Although Surry Mountain Dam significantly reduces the risk of flooding to surrounding areas, there are still moderate risks associated with the dam. The most likely scenario for downstream flooding would be an uncontrolled high volume release of water through the spillway during significant storm events. However, the dam's failure in extreme scenarios, such as the capacity being exceeded or damage to the spillway structure, could result in devastating flooding downstream, impacting towns and cities further along the river, including Hartford, Connecticut. To manage these risks, the US Army Corps of Engineers continually monitors and maintains the dam, works with emergency managers to raise awareness and preparedness, and regularly updates the emergency action plan.
Year Completed |
1941 |
Dam Length |
1800 |
Dam Height |
83 |
River Or Stream |
ASHUELOT RIVER |
Primary Dam Type |
Rockfill |
Surface Area |
260 |
Hydraulic Height |
77 |
Drainage Area |
100 |
Nid Storage |
44000 |
Structural Height |
83 |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
83 |
| Location | Reservations | Toilets |
|---|---|---|
Wheelock Park Campground
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Pilgrim Pines Camping Area
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Swanzey Lake Camping Area
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Fox Brook Tent Site
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