Mountain Brook Reservoir Dam dam
Mountain Brook Reservoir Dam
Mountain Brook Reservoir Dam, located in Jaffrey, New Hampshire, is a significant earth dam completed in 1948 primarily for recreational purposes. With a height of 18.3 meters and a storage capacity of 2460 acre-feet, this dam stands as a vital structure along the Mountain Brook, serving as a popular spot for water enthusiasts and nature lovers alike. Despite being classified as having a fair condition assessment, the dam poses a significant hazard potential and undergoes regular inspections every four years to ensure its stability and safety.
Managed by the NHDES Dam Bureau, Mountain Brook Reservoir Dam boasts a spillway width of 30 meters and a maximum discharge capacity of 3420 cubic feet per second. The dam's location in the Cheshire County offers a serene landscape encompassing a surface area of 216 acres within a 14-square mile drainage area. While the dam's risk assessment is moderate, continuous monitoring and adherence to safety protocols are crucial in mitigating any potential threats and ensuring the preservation of this essential water resource for the community and surrounding environment.
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 Mountain Brook 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 Mountain Brook Reservoir Dam.
Boat launches
- Contoocook Lake Boat Launch
- Pool Pond Boat Launch
- Grassy Pond Boat Launch
- Frost Pond Boat Launch
- Thorndike Pond Boat Launch
- Perkins Pond Boat Launch
Campgrounds
- Mt Monadnock State Park Campground
- Camp Wanocksett
- 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)
- Headwaters To North Of Searsburg Reservoir
- Begins In Franklin To Sewall's Island
Track Mountain Brook 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 Mountain Brook Reservoir Dam
Where does the data for Mountain Brook 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 Mountain Brook Reservoir Dam.