Risley Reservoir Dam dam
Risley Reservoir Dam
Risley Reservoir Dam, located in Bolton, Connecticut, serves as a vital water supply source for the Lydallville area. Built in 1853, this masonry dam stands at a height of 28 feet and has a storage capacity of 226 acre-feet, providing essential water resources for the community. With a significant hazard potential and a fair condition assessment as of the last inspection in 2014, the dam is regulated by the Connecticut Department of Energy and Environmental Protection (DEEP) to ensure its safety and reliability.
The dam, situated on Lydall Brook, has a spillway width of 42 feet and a maximum discharge capacity of 540 cubic feet per second. The surrounding area covers a surface area of 14.7 acres, with a drainage area of 0.88 square miles. Despite being modified over the years, the dam remains a crucial structure for water management in the region. With valve outlet gates and a history of regular inspections, Risley Reservoir Dam continues to play a key role in water resource management and climate resilience efforts in Tolland County.
As a locally owned dam under the jurisdiction of the state, Risley Reservoir Dam exemplifies the importance of sustainable water supply infrastructure. With Congressman Joe Courtney representing the area, the dam's primary purpose of water supply underscores its significance in meeting the community's needs. While facing some risk factors, the dam's operational and emergency preparedness measures, including a five-year inspection frequency, aim to mitigate potential hazards and ensure the continued safety and functionality of this critical water resource infrastructure.
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 Risley Reservoir Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Hockanum River Near East Hartford | 86 cfs | → |
| Broad Brook At Broad Brook | 20 cfs | → |
| Willimantic River Near Coventry | 211 cfs | → |
| North Branch Park R At Hartford | 10 cfs | → |
| Connecticut River At Thompsonville | 37,300 cfs | → |
| Natchaug River At Willimantic | 596 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Risley Reservoir Dam.
Boat launches
- Bolton Lake (Lower)
- New State Road Trail Manchester
- Coventry Lake
- Bissell Bridge (Connecticut River)
- Wilbur Cross Highway East Hartford
- Holbrook Pond
Campgrounds
Fishing spots
- Trout Hatchery
- Great Brook Reservoir
- Lower Fulton Park Pond
- Toms Creek
- Lake Washington Fishing Area
- Twotree Island Channel
Paddle runs
- Begins Below The Tailrace Of The Rainbow Dam To The Confluence With The Connecticut River
- The Confluence Of The East And West Branches To The Confluence With The Farmington River In East Granby
- Begins Below The Tailrace Of The Lower Collinsville Dam To The Route 187 Bridge
- The Confluence With The Nepaug River To A Point 0.2 Miles Below The Lower Collinsville Dam Tailrace
- New Hartford/Canton Town Line To The Confluence With The Nepaug River
- The Massachusetts-Connecticut State Line In Hartland To The Confluence With The Salmon Brook Main Stem
Track Risley Reservoir 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 Risley Reservoir Dam
Where does the data for Risley Reservoir 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 Risley Reservoir Dam.