Black Reservoir Dam dam
Black Reservoir Dam
Black Reservoir Dam, located in Jaffrey, New Hampshire, is a state-regulated earth dam with a primary purpose of recreation. Completed in 1850, the dam stands at a height of 10 feet and has a length of 180 feet, providing a storage capacity of 253 acre-feet. The dam, situated on Willow Brook, covers a surface area of 48 acres and has a drainage area of 5.6 square miles.
The dam's spillway, with a width of 25 feet, is uncontrolled, and the hazard potential of the dam is considered significant with a poor condition assessment as of May 2016. Despite its condition, the risk assessment for Black Reservoir Dam is moderate. The dam is inspected regularly, with the last inspection conducted in April 2019. The surrounding area offers opportunities for recreational activities, making it a popular destination for water resource and climate enthusiasts to explore and appreciate the intersection of nature and infrastructure.
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 Black Reservoir Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Contoocook River At Peterborough | 118 cfs | → |
| Nubanusit Bk Blw Macdowell Dam Nr Peterborough Nh | 31 cfs | → |
| Millers River Near Winchendon | 121 cfs | → |
| Priest Brook Near Winchendon | 33 cfs | → |
| S Br Ashuelot River At Webb | 25 cfs | → |
| Birch Hill Reservoir At South Royalston | 30 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Black Reservoir Dam.
Boat launches
- Grassy Pond Boat Launch
- Contoocook Lake Boat Launch
- Pool Pond Boat Launch
- Frost Pond Boat Launch
- Cunningham Pond Boat Launch
- Thorndike Pond Boat Launch
Campgrounds
- Camp Wanocksett
- Mt Monadnock State Park Campground
- Lake Dennison State Park
- North Dennison Camping Area
- East Dennison Camping Area
- Otter River State Forest
Paddle runs
- Sewall's Island To Manchester Street Bridge
- 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)
- Begins In Franklin To Sewall's Island
- Headwaters To North Of Searsburg Reservoir
Track Black Reservoir 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 Black Reservoir Dam
Where does the data for Black Reservoir 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 Significant 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 Black Reservoir Dam.