Recent Progress: Decrease

The recent biennial period of 2020-2021 saw a decrease in miles opened from dam removal projects, from 1318.7 miles in the previous period to 32.6. The workgroup attributes the especially low number of miles added this past biennial period to the effects of the COVID-19 pandemic, since fish passage activities paused for an extended period. Apart from 2019, when most of the miles were opened through one dam removal project, there has been a recent decrease in miles added annually over the past few years. This general decline in miles also reflects a drop in the number of dam removals, since the easiest and least costly dam removal projects have been completed.

Outlook: On Course

During the reporting period including 2020-2021, 32.6 additional stream miles were opened to fish passage, less than the two-year target of 132 miles. This target, set in accordance with the best available science, was established in January of 2020 after the Fish Passage Workgroup reached the goal set in the 2014 Chesapeake Bay Watershed Agreement in 2016.

While the miles opened from 2020-2021 fall well below the biennial target and overall opened miles have declined over the past few years, the Fish Passage Workgroup does not expect this to be an ongoing trend. The workgroup is working on additional projects with a focus on identifying and correcting undersized and poorly constructed stream crossings that have created fish blockage. This new focus is expected to result in some fluctuations in progress toward the biennial target of 132 fish passage miles. However, based on the expected trajectory of this work and since the current rate of miles added averages 619 miles every two years, the fluctuations in miles added are expected to continue to average above the biennial target. Therefore, the outcome is considered on course.

Data for this indicator are calculated using the Chesapeake Fish Passage Prioritization project following the removal of a dam or other barrier. Experts map and count the available upstream miles located between a removed blockage and the waterway’s headwaters or the next blockage that is in place. Dam removals and fish passage projects in Delaware, New York and West Virginia are not included in this indicator’s dataset. The prioritization tool is also used to assess potential projects.

In 2016, the Fish Passage Workgroup reached their 2025 goal to open an additional 1,000 stream miles, which was established in the 2014 Chesapeake Bay Watershed Agreement. After requesting public feedback, the Principals’ Staff Committee (PSC), in January 2020, approved an outcome modification proposed by the Fish Passage Workgroup. This modification established a new target to open an additional 132 miles every two years to fish passage. Since 1988, 30,526 miles have been opened to fish passage.

Dams, culverts and other barriers inhibit stream flow, limit stream habitat and block migratory fish from reaching their spawning grounds. Removing these barriers can restore water flow, reduce sediment build-up and allow shad, herring and other migratory species to move between fresh- and saltwater habitats.

Learn About Factors Influencing Progress

Management Strategy

To achieve this outcome, participating partners have committed to:

  • Restoring historical fish migration routes by removing dams and opening streams to the movement of fish.
  • Documenting the return of fish to opened streams by establishing the presence or absence of target species (alewife, blueback herring, American shad, hickory shad, American eel and/or brook trout) at a select number of projects within the Chesapeake Bay watershed.
  • Using the Chesapeake Bay Fish Passage Prioritization Project to implement high-priority dam removal and fish passage projects.

Monitoring and assessing progress toward the outcome will occur through data related to the number of stream miles opened each year (with a target of 132 miles opened every two years) and the presence of target species at restoration sites.

As part of the Chesapeake Bay Program’s partnership-wide implementation of adaptive management, progress toward this outcome was reviewed and discussed by the Management Board in August of 2021. It will be reviewed and discussed by the Management Board again in August 2023.

Download Management Strategy (.pdf)

Logic & Action Plan

Chesapeake Bay Program partners have committed to taking a series of specific actions that will support the management approaches listed above.


  • Supporting dam removal projects, including the removal of Daniels Dam.
  • Establishing or continuing relationships with state dam safety programs to coordinate dam removal work.
  • Continuing road/stream crossing assessments, project development and project implementation.
  • Consulting with the Chesapeake Bay Program Communications Workgroup to develop communications products.
  • Monitoring some dam removals for the presence or absence of target fish species, including National Oceanic and Atmospheric Administration (NOAA) Tier II effectiveness monitoring of Patapsco River to evaluate whether the Bloede dam removal is affecting fish migration.
  • Developing an environmental DNA (eDNA) tool to detect shad.
  • Sampling for river herring and applying river herring eDNA analysis to determine priority fish passage projects and develop habitat use models.
  • Using the Chesapeake Bay Fish Passage Project to implement high priority dam removal, culvert and fish passage projects.

Recently Completed


  • Completed the monitoring phase of the Bloede Dam removal.
  • Conducted a feasibility/design study for Daniels Dam.
  • Developed Recommendations for Aquatic Organism Passage at Maryland Road-Stream Crossings guidance.
  • Developed Dam Removal Mitigation Crediting Guidance for future mitigation projects to incentivize future dam removal projects.

Learn About Logic & Action Plan

Participating Partners

The Vital Habitats Goal Implementation Team leads the effort to achieve this outcome. It works in partnership with the Sustainable Fisheries and Healthy Watersheds goal implementation teams.

Participating partners include:

  • Maryland Department of Natural Resources (State of Maryland)
  • University of Maryland Center for Environmental Science (State of Maryland)
  • Pennsylvania Fish and Boat Commission (Commonwealth of Pennsylvania)
  • Virginia Department of Wildlife Resources (Commonwealth of Virginia)
  • National Oceanic and Atmospheric Administration
  • Natural Resources Conservation Service (U.S. Department of Agriculture)
  • U.S. Army Corps of Engineers
  • U.S. Fish and Wildlife Service
  • U.S. Geological Survey
  • American Rivers
  • Chesapeake Bay Trust
  • National Fish and Wildlife Foundation
  • The Nature Conservancy
  • Smithsonian Environmental Research Center