Overview of Stream Connectivity

Stream connectivity is important for the ecological health of the stream and downstream waters. The Water Monitoring and Assessment Program defines stream connectivity as the hydrologically connected pools and riffles that link stream habitat along a longitudinal continuum (upstream to downstream), while also recognizing the lateral dimension (connection to flood plain) and vertical connection to groundwater. Disconnected stream connectivity includes streams that are completely dry, only have pools of standing water, or have very minimal flow in which some pools and riffles are disconnected. Connected streams includes flowing bodies of water in which the pools and riffles are well connected. There are thousands of man-made structures (i.e. dams, culverts, surface and groundwater withdrawal locations) in Connecticut which negatively impact stream connectivity and can result in aquatic habitat fragmentation.

Program Development

Beginning in 2016, the Water Monitoring and Assessment Program in collaboration with the Water Quantity Program developed a cost-effective technique using trail cameras to better assess human alteration to stream connectivity.  This involves taking hourly images of streams and categorizing them into six stream connectivity categories that relate flow and habitat availability to biological processes in streams. Once a series of site images are categorized, metrics are calculated to describe the magnitude, frequency, duration, and timing components of stream connectivity.  This information is used to identify alterations in stream connectivity and inform stream management activities.