Hopkinton Dam - Dike H-2 dam
Hopkinton Dam - Dike H-2
Hopkinton Dam - Dike H-2, also known as Hopkinton Dike Elm Brook H2, is a federally owned structure located in Hopkinton, New Hampshire. Built in 1962 by the US Army Corps of Engineers, this earth dam stands at a towering height of 77 feet and serves the primary purpose of flood risk reduction along Elm Brook. With a storage capacity of 131,000 acre-feet and a surface area of 220 acres, the dam plays a crucial role in managing water levels and preventing flooding in the area.
Despite its high hazard potential, the dam is regularly inspected and monitored by the US Army Corps of Engineers to ensure its structural integrity and mitigate any potential risks. The agency works closely with local emergency managers to develop and update emergency action plans, as well as engage with the public to raise awareness and preparedness for dam-related emergencies. Through ongoing risk management measures and maintenance efforts, the USACE is committed to safeguarding the surrounding communities and ensuring the effective operation of Hopkinton Dam - Dike H-2 for years to come.
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 Hopkinton Dam - Dike H-2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Contoocook R Bl Hopkinton Dam At W Hopkinton | 1,080 cfs | → |
| Warner River At Davisville | 405 cfs | → |
| Contoocook River Near Henniker | 782 cfs | → |
| Blackwater River Near Webster | 19 cfs | → |
| Piscataquog River Bl Everett Dam | 8 cfs | → |
| Soucook River | 22 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Hopkinton Dam - Dike H-2.
Boat launches
- Maple Street Hopkinton
- Hopkinton-Everett Reservoir Boat Launch
- French Pond Boat Launch
- Hopkinton
- Depot Lane Hopkinton
Campgrounds
Paddle runs
- Sewall's Island To Manchester Street Bridge
- Begins In Franklin To Sewall's Island
- Thornton Railroad Bridge To Bridgewater/Bristol Town Line
- First Bridge Upstream On Route 100 To Confluence With West River
- Headwaters To First Bridge Upstream On Route 100
- Woodstock/Thornton Town Line To Thornton Railroad Bridge
Track Hopkinton Dam - Dike H-2 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 Hopkinton Dam - Dike H-2
Where does the data for Hopkinton Dam - Dike H-2 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 Hopkinton Dam - Dike H-2.