Fairfax County will remove nine homes to reduce flooding from Tripps Run

A major stream restoration project in the planning stages is expected to reduce flooding in the Bel Air neighborhood in the Falls Church area of Mason District.

The project calls for the demolition of nine homes on Barrett Road that were built on a floodplain. That area would be excavated to create a basin for retaining stormwater.  

About 2,600 feet of flood mitigation and stream improvements would be implemented along Tripps Run between the bridge at Annandale Road and Sleepy Hollow Park.

The project is “currently at the 35 percent design stage,” said Jacob Green of the Stormwater Planning Division at a virtual community meeting in August. That means “various aspects of the project are still being refined and are subject to change.”

The Bel Air community was developed in the late 1940s and early 1950s, Green noted. Stormwater regulations that restricted development in floodplains weren’t put in place until the 1960s and 1970s.

As a result, many of the homes near Tripps Run are subject to flooding, which has gotten worse in recent years due to several factors, including heavier, more frequent storms and inadequate stream channel capacity.

As development increased upstream, the area became more impervious, Green said. That has prevented stormwater from infiltrating into the ground, thus increasing runoff into the stream.

“Tripps Run isn’t big enough to handle all the water flowing into it,” he said.

After a heavy storm in July 2020 caused flooding in Bel Air, the county hired a consultant to produce a study comparing four options for flood mitigation.

County staff decided to pursue scenario 3, which called for removing nine homes at high risk of flooding. That option struck a balance between benefit, cost, and minimizing the overall impact to the community, Green said.

The homeowners voluntarily agreed to let Fairfax County acquire their homes. Those properties – at 6640 through 6656 Barrett Road – are needed to create space to store additional water and thus lower the water surface elevations and reduce the likelihood of future flooding of other nearby properties.

The stream channel would be reshaped to provide a more uniform cross-section, which Green said would help to promote better flow characteristics.

Related story: County will demolish homes for a flood mitigation project

The floodplain area – on the land acquired by the county – would be excavated up to eight feet in some areas and graded to provide space for water storage. After the nine homes are removed, the area will be replanted with native trees and other vegetation.

That section of Barrett Road would also be demolished. Utilities would be disconnected, removed, and/or relocated as needed.   

A sanitary sewer line under Barrett Road constrains the depth of excavation and the adjustment of the stream channel. A retaining wall would be constructed to slow runoff water heading downstream.

The bridge between Barrett Road and Holloway Road would be removed to accommodate the stream reconstruction. The county would then need to create a turnaround area off Holloway Road for emergency vehicles.  

There are 479 trees in the construction area, and 142 would be removed, Green said.

The design of the project is expected to be completed in spring 2025. Demolition of the nine homes would be done by late spring or summer of 2025. A construction timeline has not been determined.

Construction would occur on county-owned easements, county-owned properties, and the VDOT right-of-way.

Additional easements might be needed on some properties for additional grading and staging. More details are expected to be available in October.

The proposed construction entrances would be on Dashiell Road and Holloway Road at the Hollowary bridge. Barrett Road at Cofer Road would be used for access after the bridge is removed.

Fairfax County was awarded $8.98 million from the Virginia Department of Conservation and Recreation’s Community Flood Preparedness Fund for the project.