Mill River Dam dam
Mill River Dam
Mill River Dam, located in Northampton, Massachusetts, is a concrete buttress dam completed in 1939 with a primary purpose of "other." The dam stands at a height of 40 feet and has a hydraulic height of 34.6 feet, providing a maximum storage capacity of 165 acre-feet and a normal storage capacity of 26 acre-feet. With a drainage area of 54 square miles, the dam serves as a crucial structure for the Mill River Diversion.
The dam is regulated by the Department of Conservation and Recreation in Massachusetts and is classified as having a "significant" hazard potential with a "fair" condition assessment as of 2015. The dam's spillway is of the uncontrolled type, with a width of 0 feet. Despite its moderate risk assessment rating, the dam has not been modified in recent years, indicating a need for ongoing monitoring and maintenance to ensure its structural integrity and the safety of downstream areas. The dam's inspection frequency is every 5 years, with the last inspection conducted in July 2015.
Overall, the Mill River Dam plays a vital role in water resource management in Hampshire County, Massachusetts, serving as a key infrastructure for flood control and water storage. Climate and water resource enthusiasts can appreciate the historical significance and engineering design of this concrete buttress dam, while also recognizing the importance of continued regulatory oversight and maintenance to mitigate risks and ensure the long-term functionality of this essential structure in the region.
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 Mill River Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mill River At Northampton | 37 cfs | → |
| Connecticut R At Interstate 391 Bridge At Holyoke | 17,400 cfs | → |
| Westfield River At Knightville | 149 cfs | → |
| Middle B Westfield River At Goss Heights | 8 cfs | → |
| Chicopee River At Indian Orchard | 1,210 cfs | → |
| West Branch Westfield River At Huntington | 61 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mill River Dam.
Boat launches
- Mount Tom Road 900-978, Easthampton
- Kellogg Hill Road, Hatfield
- Old Apremont Way, Westfield
- Water Street 266-334, Springfield
- West Street 121, Springfield
- Red Bridge Road 16, Wilbraham
Campgrounds
- Koa Weathampton
- Westover Arb Military
- Dar State Forest
- Chester - Blanford State Forest
- Barton Cove
- Rocky Point
Fishing spots
Paddle runs
- 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
- Begins Below The Tailrace Of The Rainbow Dam To The Confluence With The Connecticut River
- New Hartford/Canton Town Line To The Confluence With The Nepaug River
- The Confluence With The Nepaug River To A Point 0.2 Miles Below The Lower Collinsville Dam Tailrace
Track Mill River 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 Mill River Dam
Where does the data for Mill River 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 Mill River Dam.