Long Pond Dam dam
Long Pond Dam
Long Pond Dam in Ayer, Massachusetts, is a gravity dam with a primary purpose of recreation. Completed in 1900, this dam stands at a height of 7.5 feet and has a hydraulic height of 4.6 feet. It has a normal storage capacity of 150 acre-feet and a maximum storage of 330 acre-feet, serving as a vital resource for the surrounding area. The dam is regulated by the Department of Conservation and Recreation in Massachusetts and is inspected regularly to ensure its structural integrity.
Located on a tributary of Cold Spring Brook, Long Pond Dam covers a surface area of 60 acres and has a drainage area of 0.93 square miles. With a hazard potential rated as low and a fair condition assessment, the dam poses a moderate risk, according to the data provided. While the dam does not have an Emergency Action Plan (EAP) in place, it meets regulatory guidelines and is subject to regular inspections to mitigate any potential hazards. Overall, Long Pond Dam plays a significant role in providing recreational opportunities while ensuring water resource management in the Middlesex County area.
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 Long Pond Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Nashua River At East Pepperell | 559 cfs | → |
| Squannacook River Near West Groton | 95 cfs | → |
| Nashoba Brook Near Acton | 8 cfs | → |
| North Nashua River Near Leominster | 167 cfs | → |
| Assabet River At Maynard | 67 cfs | → |
| North Nashua River At Fitchburg | 111 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Long Pond Dam.
Boat launches
- Great Road 687, Littleton
- Emerson Drive Littleton
- Harvard Road 314, Stow
- Flint Pond Road, Tyngsborough
- Whalom Lake Public Boat Ramp
- Pawtucket Boulevard 936-970, Lowell
Track Long Pond 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 Long Pond Dam
Where does the data for Long Pond 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 Low 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 Long Pond Dam.