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Aquatic Connectivity and Barrier Removal

Road-stream crossing in Rensselaerville, NY
This road-stream crossing in Rensselaerville, NY is a significant barrier to organisms that are heading upstream (Photo A.Meyer)

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 undersized culverts affect the hydrology, sediment transport, and water quality of streams, in addition to costing towns, counties and the state money to replace and maintain.

What are we doing?

The Hudson River Estuary Watershed has more than 1500 dams, and likely more than 15,000 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 communities, so we can focus our limited resources at the most beneficial locations.

The Culvert Prioritization Projects seeks to reconnect stream habitat, reduce localized flooding and support resilient infrastructure for municipalities. With the help of many regional and local partners, this project connects interested communities with funding sources to replace impassable, undersized culverts with fully passable, properly sized culverts.

To help communities reconnect their streams and proactively remove flooding hazards, Estuary Program grants can fund these planning and mitigation steps.

  1. Assess culverts and bridges for aquatic organism passability and storm capacity.
  2. Prioritize problem culverts within a management plan.
  3. Design replacement structures through conceptual or shovel-ready engineering plans.
  4. Fix problem culverts by upgrading infrastructure to be fully passable to fish and wildlife, and reduce local flooding hazards.

Visit our DEC webpage or project factsheet to learn about how you can get involved in the Culvert Prioritization Project.

What have we found?

The full report on the Biologically Important Barriers project can be found here.

Use our Interactive Aquatic Connectivity map to get details about aquatic barriers.

This map includes the infrastructure that we have assessed and the barriers that have been identified. Species would benefit if they could get passed the Biologically Important Barriers. We acknowledge that some of the dams included in this research are important resources, and there is no attempt to remove dams that have high community value. Check the popup information on the Culvert Prioritization Project locations for the Barrier Evaluations. These projects have shown that species would benefit if they could get passed the Biologically Important Barriers and the Culvert Project locations with poor Barrier Evaluations. The popups also include information on modeled capacity for storm events at the Culvert Prioritization Project locations. Please contact the Estuary Program if you would like the barriers in your community to be assessed.  

The following video demonstrates how infrastructure in streams impacts upstream and downstream dynamics.

Who are our partners and audience?

Using the North Atlantic Aquatic Connectivity Collaborative (NAACC) protocols organizations such as the NYS DEC, Cornell Cooperative Extension, Soil and Water Conservation Districts, county governments, and regional conservation organizations like The Nature Conservancy, Trout Unlimited and Riverkeeper have been assessing and prioritizing aquatic barriers.

Want to learn more?

Culvert Right-Sizing

Dam Removal