Great Hill Reservior Dam dam
Great Hill Reservior Dam
The Great Hill Reservoir Dam, located in Shelton, Connecticut, is a concrete structure completed in 1909 with a primary purpose of recreation. The dam spans 165 feet in length and stands at a height of 41 feet, creating a reservoir with a storage capacity of 378 acre-feet. The dam is situated on Fourmile Brook and has a drainage area of 2.66 square miles, offering a surface area of 12 acres for recreational activities.
Despite its historical significance and recreational value, the Great Hill Reservoir Dam poses a high hazard potential due to its poor condition assessment. The dam is regulated by the Connecticut Department of Energy and Environmental Protection (DEEP), with state permitting, inspection, and enforcement procedures in place. The last inspection in August 2019 indicated a need for attention to ensure the safety and functionality of the dam.
With its picturesque location and potential for outdoor enjoyment, the Great Hill Reservoir Dam serves as a vital water resource for the community. However, ongoing maintenance and risk management measures are essential to address its current poor condition assessment and high hazard potential, ensuring the safety of both the dam and the surrounding area. Enthusiasts of water resources and climate preservation can appreciate the importance of maintaining and safeguarding this historic structure for future generations to enjoy.
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 Great Hill Reservior Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Housatonic River At Stevenson | 463 cfs | → |
| Naugatuck River At Beacon Falls | 317 cfs | → |
| Pootatuck R At Sandy Hook | 21 cfs | → |
| Pomperaug River At Southbury | 68 cfs | → |
| Mill R Nr Hamden | 23 cfs | → |
| Weekeepeemee River At Hotchkissville | 20 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Great Hill Reservior Dam.
Boat launches
- Lake Housatonic
- Lake Zoar
- Huntington Street Shelton
- Main Street Hamden
- Shipyard Lane Milford
- Lake Lillinonah (Pond Brook)
Campgrounds
Fishing spots
Paddle runs
- Begins Downstream Of The Borough Of Bantam, At Stoddard Road Bridge To The Confluence With The Shepaug River
- Pond Downstream Of Shepaug Reservoir Dam, Marked By Service Road Bridge To Ends In Backwaters Of Lake Lillinonah, Near Roxbury Falls
- Kent Bridge To Boardman Bridge
- 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
Track Great Hill Reservior 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 Great Hill Reservior Dam
Where does the data for Great Hill Reservior 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 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 Great Hill Reservior Dam.