Photograph of a two people standing at the top of a small hill looking down at a creek near a newly constructed road culvert.

Barrier Removal and Mitigation

Program Summary

The objective of this program is to restore aquatic connectivity by supporting the removal of obsolete dams and replacement of undersized or improperly installed culverts at priority locations. This will improve water quality, reduce flood hazards and facilitate aquatic organism passage to foster healthy populations of recreational, commercial, migratory and resident fish species.

Check out WRI's barrier removal and mitigation work in partnership with HREP staff.

Program Goals

  • Maintain and apply a road-stream crossing modeling tool that identifies undersized culverts in counties or watersheds of interest for Hudson River Estuary Program staff and county Extension offices throughout New York State.
  • Conduct analyses on the road-stream crossing modeling tool to inform improvements.
  • Provide analyses to predict the impact of dam removals on tributaries to the Hudson River.
  • Efficiently identify previously un-inventoried dams and contribute to basin-scale dam inventories that will be of use for aquatic connectivity restoration and assessment.
  • Conduct systematic review of existing literature and reports, as well as design and implement a survey administered to aquatic connectivity stakeholders to prioritize obstacles and identify knowledge needs to identify solutions to addressing key social barriers to aquatic connectivity restoration.
  • Implement a dam barrier mitigation analysis which identifies optimal strategies to improve aquatic connectivity restoration given the realities of limited restoration budgets and on-the-ground social obstacles to barrier mitigation.
  • Establish the potential ecosystem benefits of barrier mitigation.
  • Audit existing barrier removal outreach practices and identify strategies to improve the reach and effectiveness of communication with stakeholders
  • Predict changes in waterbird biodiversity regionally as small barriers are increasingly removed.
  • Provide insight into demographic and genetic fragmentation by in-stream barriers, inform barrier removal planning, and compare the removal of culverts and dams in regard to evolutionary restoration, genetic diversity, and population extinction probability.
  • Conduct outreach and capacity building to municipalities and watershed groups to increase buy-in and support.
  • Refine messaging strategy for dam owners and nearby property owners to address social barriers to dam removal.
  • Scale municipal management plans to a tributary wide level to accelerate implementation (culvert replacement, dam removal) while pairing these projects to hazard/flood mitigation plans and natural resource inventories.
  • Continue expansion of culvert assessment efforts to characterize baseline conditions and facilitate prioritization for removal.
  • Conduct in-reach with DOW, DOT, etc. to streamline policies, regulations and permitting pertaining to dam removal and culvert right-sizing.
  • Evaluate vulnerabilities and risks  from dam failures to downstream disadvantaged and environmental justice communities.
  • Evaluate  municipal  financial  cost  benefit  analysis  of  repairing  vs.  removing  dams  to  taxpayers,  and  in  particular disadvantaged lower income communities who may not have equal access to impoundments.
  • Engage with EJ communities (decision makers and the public) to provide information, connect with local interests and values,  share  decision  support  tools  and  resources,  and  develop  designs  and  grant  applications  to  implement  priority culvert enhancement and fish passage projects that will benefit EJ communities.

Aquatic Connectivity Three-Year Summary

Three-Year Summary
Photograph of two people standing at the edge of stream looking into a net with organisms in it.

WRI supports the restoration of aquatic connectivity in waterways statewide through the removal of obsolete dams and replacement of undersized or improperly installed culverts at priority locations. 

These infrastructural changes will improve water quality, reduce flood hazards, promote asset management and facilitate aquatic organism passage to foster healthy populations of recreational, commercial, migratory and resident fish species.

WRI's Aquatic Connectivity research and outreach program supports the Hudson River Estuary Program Action Agenda, the Great Lakes Action Agenda, and established statewide priorities.

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