Swanzey Lake Dam dam
Swanzey Lake Dam
Located in Swanzey, New Hampshire, the Swanzey Lake Dam is a local government-owned structure with a primary purpose of recreation. Constructed in 1920, this earth dam stands at a height of 12 feet and spans 150 feet in length, providing a storage capacity of 641 acre-feet. The dam regulates TR Perry Brook and has a drainage area of 1.63 square miles, with a maximum discharge capacity of 545 cubic feet per second.
Despite being classified as having a low hazard potential, the Swanzey Lake Dam is regularly inspected and maintained by the New Hampshire Department of Environmental Services Dam Bureau. Its condition is deemed fair, with a moderate risk assessment rating of 3. The dam's emergency action plan status, inundation maps, and risk management measures are not currently available, suggesting a need for further preparedness and assessment in the event of a potential emergency.
Water resource and climate enthusiasts may be intrigued by the historical significance and environmental impact of the Swanzey Lake Dam, which serves as a key component of the local recreational landscape. With its close monitoring by regulatory agencies and ongoing assessments, the dam presents an opportunity for continued research and attention in the realm of water resource management and climate resilience.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Swanzey Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Ashuelot River At West Swanzey | 598 cfs | → |
| S Br Ashuelot River At Webb | 25 cfs | → |
| Ashuelot River Above The Branch | 21 cfs | → |
| Otter Brook Below Otter Brook Dam | 12 cfs | → |
| Ashuelot River At Hinsdale | 758 cfs | → |
| Ashuelot River Below Surry Mt Dam | 259 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Swanzey Lake Dam.
Boat launches
- Swanzey Lake Boat Launch
- Wilson Pond Boat Launch
- Meetinghouse Pond Boat Launch
- Perkins Pond Boat Launch
- Stone Pond Boat Launch
- Spofford Lake Boat Launch
Campgrounds
- Swanzey Lake Camping Area
- Pilgrim Pines Camping Area
- Wheelock Park Campground
- Falls Brook Shelter
- Richardson-Zlogar Cabin
- Mt Monadnock State Park Campground
Paddle runs
- First Bridge Upstream On Route 100 To Confluence With West River
- Headwaters To First Bridge Upstream On Route 100
- Headwaters To Confluence With West River (End Of Sherman Road)
- Headwaters To North Of Searsburg Reservoir
- End Of Kendall Farm Road To Confluence With West River
- Headwaters To Proclamation Boundary
Track Swanzey Lake Dam in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Swanzey Lake Dam
Where does the data for Swanzey Lake Dam come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Swanzey Lake Dam.