Sparrow Pond Update

(Updated September 2021)

Sparrow Pond, which is along the W&OD Trail, is in transition. It’s a man-made pond that the County created in 2000 to help protect Four Mile Run and to support habitat and improve water quality. Since then, the pond has filled with sediment, and the County has plans to restore the pond, adding a sediment forebay and larger pools to better filter stormwater and restore habitat for herons, ducks, turtles, frogs and fish.

In the meantime, beavers moved in and built a dam that raised the water level above what was safe for the W&OD Trail embankment. The entire pond area flooded and pools of water started to form on the bottom of the slope. A soggy, steep bank was not ideal to keep the trail stable and safe in heavy rainstorms or flash floods.

In April 2021, Arlington Parks & Recreation hired a contractor to place a beaver baffle in the pond to protect the trail. A beaver baffle is a device that uses a large plastic tube to create a hidden water exit away from the beavers’ dam. It helps stabilize the water level in the pond.

The beaver baffle was an elegant solution that allowed the beaver to stay without endangering the W&OD trail embankment. The water levels came down and the pools on the bottom of the slope dried up. The slope and trail were safer again.

What’s Next for Sparrow Pond?

Sparrow Pond is a small pond nestled between residential and urban areas. The current beavers are not the first to live there. Typically, beavers will move in and spend a few years in the Sparrow Pond area. Once they have exhausted all the trees and other vegetation around Sparrow Pond, they move on. It is likely that the beavers currently in the pond will do the same. Virginia law does not allow beavers to be relocated, so it’s best to let beavers choose when it’s time to move to a new home.

The Sparrow Pond restoration project design is still being developed and finalized. The project will restore deeper pond levels to provide habitat for birds, fish, turtles, and other wildlife – without creating problems for the W&OD trail. A beaver baffle will also be included in case other beaver families decide to make the pond their home in the future.

At project meetings, the County has heard that protecting wildlife is very important for community members. We will work together to rescue native plants and affected animals like turtles and fish before beginning construction. Before being released, staff will test the animals so we don’t spread disease around the County. By working together and finding creative solutions, we can help to protect wildlife and strengthen our connections with the natural world.