Holyoke - Overflow No. 2 dam
Holyoke - Overflow No. 2
Holyoke - Overflow No. 2 is a historic masonry dam located in Holyoke, Massachusetts, along the Holyoke Canal. Built in 1860, this dam serves a primary purpose of hydroelectric power generation, with additional benefits for recreation. With a height of 30 feet and a length of 105 feet, it has a storage capacity of 26,000 acre-feet and a maximum discharge rate of 2,615 cubic feet per second. The dam features a controlled spillway with a width of 105 feet, ensuring safe water release during high flow events.
Managed by the local government and regulated by the Federal Energy Regulatory Commission, Holyoke - Overflow No. 2 has a high hazard potential and a very high risk assessment rating. Although the condition assessment is currently not available, the dam undergoes inspections with a frequency of 1 year to ensure its safety and integrity. With emergency action plans in place and emergency contacts updated periodically, the dam is well-prepared to handle any unforeseen events and protect downstream communities in the event of a breach.
As a significant water resource structure in the region, Holyoke - Overflow No. 2 plays a crucial role in the local energy production and recreational activities. Its historical significance, combined with its modern regulatory oversight and risk management measures, make it a fascinating site for water resource and climate enthusiasts to study 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 Holyoke - Overflow No. 2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Connecticut R At Interstate 391 Bridge At Holyoke | 28,800 cfs | → |
| Chicopee River At Indian Orchard | 1,050 cfs | → |
| Westfield River Near Westfield | 388 cfs | → |
| Mill River At Northampton | 43 cfs | → |
| Swift River At West Ware | 45 cfs | → |
| Middle B Westfield River At Goss Heights | 8 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Holyoke - Overflow No. 2 .
Boat launches
- Old Apremont Way, Westfield
- Mount Tom Road 900-978, Easthampton
- Water Street 266-334, Springfield
- West Street 121, Springfield
- South End Bridge Agawam
- Red Bridge Road 16, Wilbraham
Campgrounds
- Westover Arb Military
- Koa Weathampton
- Chester - Blanford State Forest
- Primitve Camping Area
- Dar State Forest
- Granville State Forest
Fishing spots
- Lake Washington Fishing Area
- Trout Hatchery
- Great Brook Reservoir
- Lower Fulton Park Pond
- Lake Quassapaug
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
- Begins Below The Tailrace Of The Rainbow Dam To The Confluence With The Connecticut River
- The Hartland Headwaters To The Confluence With The Salmon Brook Main Stem
- 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 Holyoke - Overflow No. 2 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 Holyoke - Overflow No. 2
Where does the data for Holyoke - Overflow No. 2 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 High 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 Holyoke - Overflow No. 2 .