Public Works and Environmental Services

CONTACT INFORMATION: Our administrative offices are open 8 a.m. – 4:30 p.m., Mon - Fri
703-324-5500 TTY 711
12000 Government Center Parkway
Suite 449, Fairfax, Va 22035
Joni Calmbacher
Director, Stormwater Planning

Old Courthouse Spring Branch at Ashgrove Historic Park Stream Restoration

Project Number: SD-000031-236

Project Update: April 15, 2024

Construction to begin in Summer 2024.

Project Background

Old Courthouse Spring Branch existing conditions
Old Courthouse Spring Branch existing conditions

This project was identified in the Difficult Run Watershed Management Plan for stream restoration and stabilization activities. It was placed in the county's Fiscal Year 2019 work plan as a result of severe erosion and maintenance issues related to a downstream stormwater management basin.

Project Description

The project will restore about 2,000 linear feet of natural stream channel, replace the culvert under Ashgrove Lane and repair the trail. The stream channel exhibits severely eroded and over-widened banks, and the potential for further bed and bank instability. This project is part of larger efforts to restore many of Fairfax County’s degraded streams while improving overall water quality and the condition of the Chesapeake Bay.

The primary goals of the restoration are:

  • Stabilize the channel and prevent future erosion and degradation along the stream
  • Improve water quality through the removal of nutrients (nitrogen and phosphorous) and sediment
  • Protect the high-quality forest upstream of the Ashgrove Lane Trail
  • Replace the culvert under the Ashgrove Lane Trail and repair the trail. If the culvert fails, there will be massive erosion and tree loss in the upstream forested area
  • Create a healthy ecosystem by restoring the channel and planting native trees and herbaceous plants

Project Location

The project is located on public land and within stormwater easements south of the Dulles Access Road, extending downstream through Old Courthouse Spring Branch Stream Valley Park to Ashgrove Lane.

View the downloadable map. The project area is shown in blue.

Project Timeline

Construction to begin in Summer 2024.

Project Benefits

The environmental benefits of the project are:

  • Improved watershed conditions
  • Reduced downstream impacts by controlling velocity, reducing erosion, protecting infrastructure
  • Improved buffer quality

Project Cost and Funding Source

Design of the Old Courthouse Spring Branch at Ashgrove Historic Park stream restoration project is funded for $900,000. Construction funding is dependent upon future budget availability and allocations. Stormwater projects are funded through the county Stormwater Service District.


For more information please email Project Manager Ken Trinh, Stormwater Planning Division, Department of Public Works and Environmental Services, or call 703-324-5802, TTY 711.

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