Powder Mill dam
Powder Mill
Powder Mill, a historic hydroelectric dam located in South Barre, Massachusetts, has been generating clean energy since its completion in 1908. Designed by L. B. Dow, this gravity dam stands at 10 feet tall and spans 340 feet in length, holding a storage capacity of 336 acre-feet. Situated on the Ware River, the dam's maximum discharge capacity reaches 7100 cubic feet per second, making it a significant source of renewable power for the region.
Managed by a private owner, Powder Mill is regulated by the Federal Energy Regulatory Commission and undergoes inspections every three years to ensure its structural integrity. With a low hazard potential and a moderate risk assessment, the dam plays a crucial role in water resource management and climate resilience efforts in Worcester County. Although not state-regulated, the dam continues to provide valuable hydroelectric power while minimizing environmental impact on the surrounding area.
Powder Mill's historical significance and sustainable energy production highlight its importance in the region's water infrastructure. As a gravity dam with uncontrolled spillways and a moderate risk assessment, it serves as a key player in the transition towards a more resilient and renewable energy future. With its capacity to generate clean power and regulate water flow on the Ware River, Powder Mill exemplifies the intersection of water resource management and climate action, making it a noteworthy site for enthusiasts in these fields to explore and appreciate.
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 Powder Mill -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Ware River At Intake Works Near Barre | 139 cfs | → |
| Ware River Near Barre | 91 cfs | → |
| East Branch Swift River Near Hardwick | 74 cfs | → |
| Sevenmile River Near Spencer | 16 cfs | → |
| Quinapoxet River At Canada Mills Near Holden | 27 cfs | → |
| Otter River At Otter River | 105 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Powder Mill .
Boat launches
- Hardwick Road, Hardwick
- Dana Road, Petersham
- Overlook Drive 16-18, Spencer
- Shore Road 83, North Brookfield
- Cottage Street 2-38, West Brookfield
- Walter Drive 2-98, Ware
Campgrounds
- Federated Womens' Club State Forest Primitive Campsite
- Beaman Pond Campground
- Otter River State Forest
- East Dennison Camping Area
- Lake Dennison State Park
- North Dennison Camping Area
Paddle runs
- Begins Below The Tailrace Of The Rainbow Dam To The Confluence With The Connecticut River
- The Massachusetts-Connecticut State Line In Hartland To The Confluence With The Salmon Brook Main Stem
- The Confluence Of The East And West Branches To The Confluence With The Farmington River In East Granby
- The Hartland Headwaters To The Confluence With The Salmon Brook Main Stem
Track Powder Mill 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 Powder Mill
Where does the data for Powder Mill 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 Powder Mill .