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Watershed Management Conference

Reston, Virginia | –

Technical Tours

Technical Tour: Fairfax County Stormwater Management Facility 3 (Stream Restorations) Ticketed event
Tuesday, August 11, 2026 | 1:00 p.m. - 5:00 p.m.
$50 EB / $50 ONS

As decades of urban development have altered hydrology throughout Fairfax County, many stream systems within the Difficult Run watershed have experienced severe channel incision, bank erosion, habitat degradation, and loss of floodplain connectivity. This field tour will highlight three stream restoration projects that demonstrate Fairfax County’s approach to stabilizing highly eroded urban channels through natural channel design. Participants will observe how these projects address multiple objectives, including improvement of downstream water quality, reduction of sediment transportation, protection of public infrastructure, ecological restoration, and invasive species management. The tour will also discuss lessons learned from implementing stream restoration in a mature and continually evolving watershed.

Technical Tour: Loudoun County Stormwater Management Facility (River Bend Stream Restoration and Willow Lake) Ticketed event
Tuesday, August 11, 2026 | 1:00 p.m. - 5:00 p.m.
$50 EB / $50 ONS

River Bend Stream & Outfall Restoration Project
The River Bend Stream & Outfall Restoration project, which was completed in the fall of 2025, made improvements to a Potomac River tributary that flows between River Bend Middle and Potomac Falls High schools in CountrySide. The restoration project area is on the north side of Algonkian Parkway. The project, which began in October 2023, was established to increase animal habitat, improve local water quality and reduce pollutants and sediments flowing into the Chesapeake Bay watershed. The project restored 3,125 linear feet of the stream and reintroduced native species, resulting in the planting of approximately:

  • 600 trees.
  • 6,000 live stakes. Live stakes are stem cuttings inserted directly into the stream bank; the developing root networks help reduce soil loss.
  • 5,000 sage and rush grass plugs.

Riparian and upland seeding along and above the banks of the stream also were included.  
The project helped achieve state and federal requirements to reduce pollutants into the Chesapeake Bay from local streams and is estimated to:

  • Eliminate more than 200 pounds of phosphorus per year.
  • Eliminate more than 500 pounds of nitrogen per year.
  • Prevent more than 130,000 pounds of total suspended solids, such as sediment or particles that do not dissolve in water, from reaching the Potomac.

Willow Lake (Active Construction Site)

The project will reduce the amount of phosphorous flowing into Willow Lake, which is part of the Chesapeake Bay Watershed. Phosphorous is a pollutant, and reducing the amount heading toward the Chesapeake Bay Watershed helps Loudoun achieve state-mandated pollution-reduction goals set by the Virginia Department of Environmental Quality. This project is expected to reduce those pollutants by the following amounts:

  • Phosphorus reduction 11 pounds per year
  • Nitrogen reduction 24 pounds per year

The project will:

  • Dredge 10,000 cubic yards of sediment from Willow Lake
  • Establish an aquatic bench around the edge of the lake. An aquatic bench is area with low-lying vegetation where the water level fluctuates. They provide enhanced pollution removal and reduce shoreline erosion. It is also a safety feature of a pond.
  • Add forebays to collect sediment and debris flowing into the pond
  • Create fishing pads. The fishing pads are an enhancement for the community to be able to access the lake for recreational purposes.

Fun fact about Willow Lake: we are currently relocating turtles from the pond ahead of the dredging – so far the turtle count is around 165 and we are expecting well over 200 turtles to be relocated.

Tap Rock Water Treatment Facility (Loudoun Water) (ticketed event)
Tuesday, August 11, 2026 | 1:00 p.m. - 5:00 p.m.
$50 EB / $50 ONS

The Tap Rock Water Treatment Facility, commissioned in 2018, is a 21 MGD facility utilizing pretreatment with ozonation, coagulation, flocculation, sedimentation, settled water ozonation, filtration with biological GAC filters, UV, and chloramine disinfection.  Raw water is pumped from the Potomac River and travels five miles to the facility. The facility has no discharge to the river. Residuals processing utilizes plate setters and thickeners and the treated stream is recycled to the head of the treatment process.

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