Fairfax County details Bren Mar Park stream restoration; construction eyed for summer 2027

A Fairfax County staff member presented a plan to restore and stabilize about 2,000 feet of stream channel and tributaries in Bren Mar Park, aiming to reduce erosion, repair failed slopes and protect adjacent water and sewer infrastructure.

The presenter said the project will begin just downstream of I-395 and run through the park to a point just upstream of the Bren Mar Recreation Association property. "The project consists of about 2,000 ft of stream restoration and stabilization of the stream channel and tributaries within Bren Mar Park," the presenter said.

County staff framed the work as necessary because erosion and stream migration have caused slope failures in multiple places and currently threaten utilities. "This poses a pretty big safety hazard as there's an existing natural surface trail, which travels right along the top of that slope," the presenter said, explaining that some slope drops in the middle of the park exceed 10 feet.

The plan identifies two primary problem areas: one mid-park, where failed slopes threaten a trail, and a downstream area where the channel has migrated close to a water line and sewer line. The presenter said exposing or damaging the utilities could be costly to repair and could interrupt service.

Design and methods The county will use natural channel design principles, placing wood and stone structures such as cross vanes, reinforced bed material and floodplain wood assemblages to control grade, slow flows and reduce erosion while improving habitat. For the mid-park area, the presenter said the design would pull the stream centerline away from the slope, rebuild and stabilize the slope with toe protection and vegetation. For the downstream area, the plan calls for shifting the channel away from the utilities and adding soil cover and other stabilizing measures.

Construction impacts and mitigation During construction, residents should expect noise, construction traffic using Colliers Lane, safety barriers and phased trail closures with detours. The presenter said contractors will be expected to comply with Fairfax County's noise ordinance and a construction safety resolution requiring a safe, neat and clean work area. Several bridges that provide mid-park cross connections will be closed while work is under way, though parallel routes are planned to maintain some connectivity.

Trees, revegetation and monitoring County staff said crews surveyed 830 trees in the park larger than 12 inches in diameter; 57 trees larger than 12 inches were identified for removal, and about half of those show potential for reuse as woody structures in the restored channel. The project will include a planting plan and invasive species management and will monitor restoration work for a minimum of one year post-construction to encourage plant survival and invasive-species control.

Schedule and next steps Design is expected to be finished in the summer (the presenter referred to this as "this year" in the presentation). Staff said they are working to acquire permits, will run a bidding process after design is complete, and anticipate construction could begin around the summer of 2027, though an exact start date is not yet determined. The presenter said the county will provide a status update after design completion and hold a partner meeting before construction to discuss expectations and answer questions.

The presentation closed with an invitation for questions from attendees.