Maryland Removes Old Dam to Open 35 Miles of Habitat

The removal of the Cypress Branch Dam significantly expands available stream space for migratory fish species.

Updated on Oct. 28, 2026 in Environmental

Maryland Removes Old Dam to Open 35 Miles of Habitat

Live Poll

Should government agencies prioritize removing abandoned dams to restore natural fish habitats?

Maryland officials completed the removal of the Cypress Branch Dam in April 2025. The project has successfully opened more than 35 miles of upstream habitat for migratory fish species including hickory shad and herring.

Why it matters

The restoration improves connectivity within the Chesapeake Bay watershed, significantly exceeding the original project estimates for habitat recovery. This effort reflects a broader regional commitment to restoring migratory pathways for aquatic populations.

The completed project reconnected 35 miles of habitat, nearly doubling the 18 miles initially projected by planners. Monitoring teams are now assessing the site to determine if local fish populations migrate into these newly accessible reaches.

The players

Maryland Department of Natural Resources

The state agency responsible for managing Maryland's public lands, including Cypress Branch State Park, and leading conservation projects.

Chesapeake Bay Program

A regional partnership that coordinates restoration efforts across the watershed to meet specific ecological milestones.

The details

Crews executed the restoration by demolishing the concrete spillway and removing sections of the earthen dam constructed around 1900. Engineers also straightened the canal and installed root wads, which are clusters of tree roots and stems used to stabilize stream banks. This mechanical intervention removes the primary physical barrier that previously blocked migratory routes for alewife, blueback herring, and hickory shad.

1760s: Thomas Gilpin owned the estate.
1900: Estimated construction date of the dam.
1994: Maryland purchased the mill pond property.
2019: Work began with soil testing.
April 2025: Removal of the dam was completed.

The Tech Race

This project contributes directly to the Chesapeake Bay Program's long-standing goal of opening 1,000 stream miles by 2025. It builds on momentum from 2022 and 2023, during which the program opened 303 stream miles throughout the watershed.

Residents and visitors to Cypress Branch State Park can now observe a restored, free-flowing stream environment that replaces the former mill pond. Future ecological health in the area depends on the success of fish populations naturally recolonizing these reconnected waters.

The takeaway

The successful removal of this century-old barrier highlights the efficacy of targeted habitat restoration over initial conservative estimates. Observers should track the upcoming monitoring reports from the state to see if the migratory shad and herring populations demonstrate sustained recovery.