D.F. Riley Grist Mill Dam dam
D.F. Riley Grist Mill Dam
The D.F. Riley Grist Mill Dam, located in Hatfield, Massachusetts, is a historic masonry dam constructed in 1881 along the Mill River. This dam serves a primary purpose of recreation, providing a serene backdrop for outdoor enthusiasts and water resource aficionados alike. With a height of 19 feet and a hydraulic height of 14 feet, the dam holds a storage capacity of 580 acre-feet and covers a surface area of 0.05 square miles.
Despite its historical significance and recreational value, the D.F. Riley Grist Mill Dam is classified as having a significant hazard potential and a poor condition assessment. It is regulated by the Department of Conservation and Recreation in Massachusetts, with state jurisdiction and permitting in place. The dam's inspection frequency is every 5 years, with the most recent assessment in May 2018 revealing the need for maintenance and potential risk management measures.
Climate and water resource enthusiasts are drawn to the D.F. Riley Grist Mill Dam not only for its historical charm but also for the conservation efforts required to maintain its integrity. With a moderate risk assessment rating and a need for improvements in condition, this dam represents a focal point for balancing the preservation of natural resources with the safety and recreational opportunities it provides to the local community and visitors.
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 D.F. Riley Grist Mill Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mill River At Northampton | 37 cfs | → |
| Deerfield River Near West Deerfield | 626 cfs | → |
| Connecticut R At Interstate 391 Bridge At Holyoke | 17,400 cfs | → |
| South River Near Conway | 20 cfs | → |
| West Branch Swift River Near Shutesbury | 14 cfs | → |
| Westfield River At Knightville | 149 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near D.F. Riley Grist Mill Dam.
Boat launches
- Kellogg Hill Road, Hatfield
- Mount Tom Road 900-978, Easthampton
- Old Apremont Way, Westfield
- Water Street 266-334, Springfield
- Red Bridge Road 16, Wilbraham
- West Street 121, Springfield
Campgrounds
- Koa Weathampton
- Dar State Forest
- Westover Arb Military
- Barton Cove
- Chester - Blanford State Forest
- Erving State Forest
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
- Stamford Town Line To Confluence With City Stream
- New Hartford/Canton Town Line To The Confluence With The Nepaug River
Track D.F. Riley Grist Mill 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 D.F. Riley Grist Mill Dam
Where does the data for D.F. Riley Grist Mill 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 D.F. Riley Grist Mill Dam.