Unionville Pond Dam dam
Unionville Pond Dam
Unionville Pond Dam, located in Holden, Massachusetts, is a State-regulated structure under the jurisdiction of the Department of Conservation and Recreation. Built in 1909, this Earth-type dam serves primarily as a Fish and Wildlife Pond, with additional recreational purposes. With a height of 21 feet and a storage capacity of 380 acre-feet, the dam spans 150 feet across Chaffins Brook and covers a surface area of 19 acres.
The dam's hazard potential is deemed significant, with a fair condition assessment as of June 2017. The inspection frequency is every 5 years, with the last inspection conducted on June 30, 2017. The dam's risk assessment is moderate, indicating a level 3 risk. While there are no associated locks or outlet gates, the spillway type is listed as uncontrolled, and the structure's design features a buttress core with an unlisted/unknown foundation.
Unionville Pond Dam plays a crucial role in maintaining the local ecosystem and providing recreational opportunities for the community. Its regulation and inspection by the State ensure the safety and sustainability of the dam, mitigating potential risks and ensuring its continued function for both wildlife and human enjoyment.
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 Unionville Pond Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Quinapoxet River At Canada Mills Near Holden | 25 cfs | → |
| Stillwater River Near Sterling | 16 cfs | → |
| Ware River Near Barre | 79 cfs | → |
| Sevenmile River Near Spencer | 15 cfs | → |
| Quinsigamond River At North Grafton | 15 cfs | → |
| North Nashua River Near Leominster | 114 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Unionville Pond Dam.
Boat launches
- Sewell Drive Shrewsbury
- Tamarack Lane 37, Shrewsbury
- Overlook Drive 16-18, Spencer
- Oak Island Boat Ramp
- Bartlett Street 152, Northborough
- Emerald Bracelet, Northborough
Campgrounds
- Pearl Hill Campground
- Damon Pond Campground
- Otter River State Forest
- Beaman Pond Campground
- "The Sandpits" Private Hiking And Winter Sports Area
- Grotonwood
Paddle runs
Track Unionville 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 Unionville Pond Dam
Where does the data for Unionville 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 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 Unionville Pond Dam.