Department of Environmental Conservation

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Aquatic Connectivity and Barrier Removal

Restoring Free-Flowing Rivers in the Hudson River Watershed

Dam on the Mill Creek
The first barrier from the Hudson on
the Mill Creek, City of Rensselaer, is a
barrier to fish and wildlife.

Reconnecting Our Streams

Map of Identified Aquatic Barriers (Leaves DEC website)

Fish and many other organisms use rivers and streams as pathways to move between feeding, nursery and breeding grounds. Long stretches of connected stream habitat can be resilient to changes in climate and land use. Dams and many culverts are blocking those pathways and dramatically shrinking the habitat available. At the same time, dams and culverts that are too small affect hydrology, sediment transport, and water quality of streams, and cost money for towns and the state to replace and maintain.

A Student Conservation Association Excelsior Corps member records dimensions of a culvert
A Student Conservation Association Excelsior Corps
member records dimensions of a culvert. This culvert
is perched: water drops out of the structure and into
the stream, disconnecting the stream.

The Hudson River Estuary Watershed has more than 1600 dams, and likely more than 20,000 culverts. The Hudson River Estuary Program and many partners are working towards restoring free flowing tributaries to the Hudson River. Several projects are helping to prioritize which aquatic barriers are the most detrimental to our fish and human communities, so we can focus our limited resources at the most beneficial locations. Culvert assessments for approximately 54% of the Estuary Watershed have been done so far. The map below shows where assessments have been done and what partners are working with the Hudson River Estuary Program on these barrier projects. Please visit our project factsheet (PDF) to learn more about how your community can reconnect its streams.

With the help of partnerships with Soil and Water Conservation Districts, non-profits like Trout Unlimited, the private sector and our town and county municipal partners, the Estuary Program is piloting Municipal Management Plans to assist communities in prioritizing culvert replacement. In addition to restoring free flowing streams for migratory and resident fish, and assisting communities in becoming more resilient to climate change, these documents will serve as a resource for the municipality going forward.

A map of the progress of the Culvert Prioritization Project

For the most up-to-date information about known aquatic barriers, please visit Cornell Water Resources Institute Aquatic Connectivity and Barrier Removal web page (leaves DEC website). Please contact the Hudson River Estuary Program if you have any questions about dam removal, culvert mitigation, or aquatic connectivity.

Barrier Mitigation

In the summer of 2016, 5 miles of upstream habitat was reconnected on the East Branch Wappinger Creek in Dutchess County with the removal of the Shapp Pond Dam. Watch a short video to learn more about the dam removal (leaves DEC website).

Dam Removal and Culvert Mitigation