Neponset River Dam dam
Neponset River Dam
The Neponset River Dam, located in Walpole, Massachusetts, is a masonry dam with a primary purpose of "Other." Completed in 1850, this historic structure stands 15 feet high and has a hydraulic height of 11 feet, with a storage capacity of 153 acre-feet. The dam regulates the flow of the Neponset River and is under the jurisdiction of the Department of Conservation and Recreation in Massachusetts.
Despite its low hazard potential, the Neponset River Dam is currently in poor condition and is rated as having a moderate risk level. The last inspection in 2009 revealed the need for improvements, yet the structure remains in operation. With a drainage area of 10.9 square miles, the dam plays a crucial role in managing water resources and protecting the surrounding community from potential flooding events.
As climate change continues to impact water resources and infrastructure, the Neponset River Dam serves as a reminder of the importance of maintaining and updating aging structures to ensure the safety and resilience of our water systems. With a risk management plan in place and regular inspections, efforts can be made to address the dam's poor condition and enhance its ability to withstand future challenges posed by a changing climate.
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 Neponset River Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Neponset River At Norwood | 15 cfs | → |
| East Branch Neponset River At Canton | 19 cfs | → |
| Charles River At Medway | 68 cfs | → |
| Neponset River At Greenlodge St Near Canton | 76 cfs | → |
| Charles River At Dover | 154 cfs | → |
| Mother Brook At Dedham | 48 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Neponset River Dam.
Boat launches
- Beach Street Sharon
- Blue Trail Sherborn
- Bridge Street 1, Dover
- Lake Street Sherborn
- Ames Street Dedham
- Providence Highway 267, Dedham
Track Neponset 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 Neponset River Dam
Where does the data for Neponset 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 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 Neponset River Dam.