First Connecticut Lake Dam dam
First Connecticut Lake Dam
First Connecticut Lake Dam, located in Pittsburg, New Hampshire, stands as a vital structure along the Connecticut River, serving a primary purpose of hydroelectric power generation. Completed in 1930, this earth dam boasts a height of 56 feet and a length of 1117 feet, providing a storage capacity of 114,000 acre-feet and a surface area of 2800 acres. With a maximum discharge capacity of 20,600 cubic feet per second and a spillway width of 338 feet, the dam plays a crucial role in managing water resources in the region.
Despite its age, the dam is regulated, inspected, and enforced by the New Hampshire Department of Environmental Services Dam Bureau, ensuring its structural integrity and operational safety. The dam has a fair condition assessment as of June 2015, with a high hazard potential and moderate risk assessment rating. While the dam meets guidelines for emergency action plans, there is room for improvement in terms of risk management measures and inundation mapping. Enthusiasts of water resources and climate will find First Connecticut Lake Dam to be a fascinating example of infrastructure that combines historical significance with environmental stewardship and hydroelectric innovation.
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 First Connecticut Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Connecticut R Below Indian Stream Nr Pittsburg | 332 cfs | → |
| Diamond River Near Wentworth Location | 315 cfs | → |
| Androscoggin River At Errol | 2,410 cfs | → |
| Connecticut River At North Stratford | 1,420 cfs | → |
| Upper Ammonoosuc River Near Groveton | 511 cfs | → |
| East Branch Passumpsic River Near East Haven | 128 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near First Connecticut Lake Dam.
Boat launches
- First Connecticut Lake Boat Launch
- Back Lake Boat Launch
- Back Pond Boat Launch
- Chemin Du Lac Saint-Malo
- Lake Access Road Canaan
- Cottage Road Averill
Track First Connecticut 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 First Connecticut Lake Dam
Where does the data for First Connecticut 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 First Connecticut Lake Dam.