Mascoma Lake Dam dam
Mascoma Lake Dam
Mascoma Lake Dam, located in Lebanon, New Hampshire, is a concrete structure with a buttress core type that was completed in 1881. The dam stands at a height of 18 feet and stretches for 575 feet, creating a reservoir with a maximum storage capacity of 18,300 acre-feet. The primary purpose of the dam is for recreation, and it is regulated by the NHDES Dam Bureau.
Despite its historical significance, Mascoma Lake Dam is currently rated as having a high hazard potential and a poor condition assessment. The last inspection in October 2020 revealed the need for improvements, with the dam being labeled as a moderate risk (3). With a drainage area of 153 square miles and a maximum discharge capacity of 17,255 cubic feet per second, ensuring the structural integrity and safety of the dam is crucial for the surrounding community and the environment.
As water resource and climate enthusiasts, it is important to monitor the maintenance and potential risks associated with Mascoma Lake Dam. With its significant storage capacity and location on the Mascoma River, the dam plays a vital role in the local ecosystem and recreational activities. Continued inspections, risk assessments, and potential management measures will be essential to safeguarding this important infrastructure for future generations.
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 Mascoma Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Connecticut River At West Lebanon | 6,790 cfs | → |
| Ottauquechee River At North Hartland | 394 cfs | → |
| Ompompanoosuc River At Union Village | 16 cfs | → |
| White River At West Hartford | 1,370 cfs | → |
| Baker River Near Rumney | 367 cfs | → |
| Sugar River At West Claremont | 431 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mascoma Lake Dam.
Boat launches
- Mascoma Lake Boat Launch
- Crystal Lake Boat Launch
- Connecticut River Boat Launch
- George Pond Boat Launch
- Grafton Pond Boat Launch
- Mcdaniels Marsh Boat Launch
Campgrounds
Fishing spots
Paddle runs
- Thornton Railroad Bridge To Bridgewater/Bristol Town Line
- Source Above Fr 55 To Proclamation Boundary (Stony Brook)
- Begins In Franklin To Sewall's Island
- Headwaters To Woodstock, Vt
- Woodstock/Thornton Town Line To Thornton Railroad Bridge
- Headwaters To Crossing Of Route 100 Near Route 155
Track Mascoma 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 Mascoma Lake Dam
Where does the data for Mascoma 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 High 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 Mascoma Lake Dam.