Derby Dike dam
Derby Dike
Derby Dike, also known as Lake Housatonic Dike, is a private structure located in Derby, Connecticut, along the Housatonic River. Built in 1870, this earth dam stands at a height of 10 feet and stretches 400 feet in length, serving primarily for hydroelectric purposes. With a storage capacity of 4400 acre-feet and a surface area of 325 acres, Derby Dike plays a crucial role in flood risk reduction, water supply, and recreational activities in the region.
Managed by the Federal Energy Regulatory Commission, Derby Dike has a low hazard potential and a high risk assessment rating. Although it is not state-regulated, it undergoes inspections every three years to ensure its structural integrity and safety. While the dam does not have a spillway, it is designed to efficiently manage water flow and prevent potential flooding. It is a significant asset in the New England District, contributing to the overall water resource management and climate resilience efforts in the area.
As a key feature along the Housatonic River, Derby Dike plays a vital role in managing water resources and supporting various activities in the region. With its historical significance and ongoing maintenance, this earth dam continues to be a valuable asset for flood control, hydroelectricity generation, and recreational opportunities. Its location and design reflect a harmonious balance between human development and environmental preservation, making it a noteworthy site for water resource and climate enthusiasts to explore 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 Derby Dike -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Housatonic River At Stevenson | 495 cfs | → |
| Naugatuck River At Beacon Falls | 657 cfs | → |
| Pootatuck R At Sandy Hook | 43 cfs | → |
| Rooster River At Fairfield | 10 cfs | → |
| Mill R Nr Hamden | 54 cfs | → |
| Pomperaug River At Southbury | 121 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Derby Dike .
Boat launches
- Lake Housatonic
- Huntington Street Shelton
- Main Street Hamden
- Shipyard Lane Milford
- Housatonic River State Boat Launch
- April Street 3, West Haven
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 Derby Dike 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 Derby Dike
Where does the data for Derby Dike 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 Derby Dike .