Nepaug Dam Dam
Nepaug Dam
Nepaug Dam, located in Collinsville, Connecticut, stands as a vital structure for water supply purposes, serving as a key reservoir along the Nepaug River. Built in 1918, this concrete dam boasts a height of 113 feet and a length of 650 feet, with a storage capacity of 40,540 acre-feet and a drainage area of 31.9 square miles. The dam plays a crucial role in managing water resources in the region, with a normal storage capacity of 29,300 acre-feet and a maximum discharge of 7,200 cubic feet per second.
With its high hazard potential and satisfactory condition assessment, Nepaug Dam remains under state regulation and inspection by the Department of Energy and Environmental Protection (DEEP) in Connecticut. The dam features an uncontrolled spillway, valve outlet gates, and is primarily constructed on rock foundations. Despite its age, the dam continues to meet regulatory guidelines, with a moderate risk assessment rating of 3. The associated structures, CT00370S02 and CT00370S03, further support the functionality and resilience of the Nepaug Dam complex, ensuring the efficient management of water resources and mitigating potential risks to the surrounding communities.
Nepaug Dam's historical significance, engineering design, and operational efficiency make it a noteworthy landmark in water resource management within Litchfield County, Connecticut. As a key component of the region's infrastructure, the dam exemplifies the importance of sustainable water supply practices and effective risk management strategies in the face of climate change and evolving environmental challenges. With a strong regulatory framework in place and a commitment to ongoing inspections and maintenance, Nepaug Dam continues to play a crucial role in ensuring the resilience and reliability of water resources for the local community and beyond.
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 Nepaug Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Burlington Brook Near Burlington | 1 cfs | → |
| Farmington River At Unionville | 143 cfs | → |
| West Branch Farmington River At Riverton | 119 cfs | → |
| Still River At Robertsville | 15 cfs | → |
| Farmington River At Tariffville | 263 cfs | → |
| North Branch Park R At Hartford | 4 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Nepaug Dam.
Boat launches
See all →
Campgrounds
See all →
Fishing spots
See all →
River runs
See all →
About Nepaug Dam
Where does the data for Nepaug 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 below 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.
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.