Cypress Branch Dam Removal

Princeton Hydro was contracted by American Rivers to lead project design, permitting, and construction support for the removal of the Cypress Branch Dam. Located within Maryland’s Millington Wildlife Management Area, Cypress Branch Dam was an aging and obsolete structure owned by the Maryland Department of Natural Resources. Although its exact construction date is unknown, evidence suggests the concrete spillway was built around 1900, replacing an even earlier history of dams and mill ponds in the area dating back to the eighteenth century. Despite being partially breached and in an advanced state of disrepair, the dam continued to impound water and disrupt natural stream processes, creating a barrier to fish movement and posing a public safety concern.

American Rivers partnered with the Maryland Department of Natural Resources and secured funding from the National Fish and Wildlife Foundation, the Environmental Protection Agency, and the U.S. Fish and Wildlife Service to advance the removal of a portion of the dam. The project’s primary goal was to restore a free-flowing stream through the former impoundment and reconnect more than 35 miles of upstream habitat for river herring, American shad, hickory shad, yellow perch, and other resident fish. Project benefits included:

• A man-made impoundment restored to a free-flowing stream bordered by a riparian wetland community
• Fish passage and movement of other aquatic organisms
• Reconnection of formerly isolated populations and stream habitats upstream and downstream of the dam
• Removal of a public safety hazard

After project award in 2020, and following extensive site investigations, Princeton Hydro developed a design that removed the concrete spillway and earthen embankment while reusing all demolition materials onsite to fill breach channels and scour features, eliminating the need for off-site disposal. The project also incorporated innovative bank stabilization measures using trees cleared from the site and included the design and approval of a permanent railroad crossing to maintain site access. Princeton Hydro assisted American Rivers with the procurement of a qualified construction contractor, preparation of the technical specifications and opinion of probable cost, and an on-site visit for interested firms. Princeton Hydro provided construction oversight throughout the removal effort from January through April 2025 and continues to support post-construction monitoring of the trees planted under the approved Forest Conservation Plan, as well as other vegetation, to ensure long-term restoration success.