Dam Sketch

What is a dam?

Dams are man-made or artificial barriers (earth or combinations of earth and other materials) usually constructed across a stream channel to impound water.  Dams provide a range of economic, environmental, and social benefits, including recreation, flood control, water supply, hydroelectric power, waste management, river navigation, and wildlife habitat.

Dams are typically provided with spillway systems constructed of non-erosive materials such as concrete or rock to safely pass a broad range of flows over, around or through the dam. 

Dams are typically constructed with a drain or similar mechanism to control water levels in an impoundment for normal maintenance or emergency purposes.

State-Owned Dams and Flood Control Systems - Information on dams owned by the State of Connecticut and ongoing project updates. 


Dam Safety Regulatory Program -  All dams in the State of Connecticut (which are not otherwise regulated by the Federal Energy Regulatory Commission, the United States Army Corps of Engineers, or a local municipality) are governed by the Dam Safety Regulatory Program.


Public Safety - Be aware of boating or swimming near low head dams! 
A "low head" or "run-of-the-river" dam is a dam across a watercourse that is small and often submerged under the flowing water.  They are typically low in height being 12 feet tall or less but they are deceptively dangerous. They can trap and drown swimmers, paddlers, or other water users who pass over the dam into the turbulent waters below the dam. The circulating action of the water passing over the dam can suck persons and their boats into the base of the dam and prevent their escape.  You have no way of knowing how deep a scour hole below this dam may be and may not realize how the weight of the flowing water will trap you should you go over. As an example, the Wallace Dam on the Quinnipiac River in Wallingford is a low head dam that at times can be very dangerous. 
The following photos show the Wallace Dam during lower flow periods:
Wallace Dam from fish ladder Wallace Dam from upstream
Be aware and stay clear of low head dams. Turn back and warn others you see in the area to do the same.



Additional References:

NOAA National Weather Service– Comprehensive weather information

Intellicast - Commercial weather site

Accuweather – Commercial weather site


NOAA Atlas 14 for the northeast is now available.

Precipitation frequency estimates for CONNECTICUT updated 9-30-2015

Current NWS Probable Maximum Precipitation (PMP) Documents

NOAA Precipitation History – 24 hour and weekly accumulations

Intellicast 24-hour precipitation accumulation

River Information

NOAA River Gauge –  Real time river data with hydrographs 

USGS Water Watch – Maps of high flow and flooding locations, and real-time stream flow

Content last updated on October 2019