Sparrow Pond Restoration

February-March 2024 Update

The Four Mile Run trail has reopened. The team excavated, placed concrete outfall structures, and stabilized the area to build a new outfall from Sparrow Pond to Four Mile Run. Thank you to everyone who exercised caution and followed detour signage.

W&OD Trail Detour Anticipated to Start on Monday, February 19 (Presidents' Day)

There will be a detour of the W&OD trail near Sparrow Pond anticipated to start on Monday, February 19th (Presidents' Day). The work will allow the construction team to finish the new outfall that will connect Sparrow Pond to Four Mile Run.

February-March Update

In February and March, the contractor will be working on the following:

• New outfall construction: Excavating and installing pipe segments in the new outfall to connect Sparrow Pond to Four Mile Run. A section of the W&OD trail will be closed to complete this work. See more on the W&OD trail detour above. 
• Most habitat structures have been installed, including turtle basking logs, root wad habitat structures, and poles for wood duck boxes. Wood duck boxes will be installed in the spring. Once the outfall is completed, work will resume on the remaining pools.
• Large equipment may be coming through the neighborhood during work hours. S Park Drive neighbors, we appreciate your patience!

The South Park Drive trail spur is being shared between walkers, cyclists, and construction vehicles. We ask that users of this connector trail please:

• Keep a wide distance from active equipment.
• Watch for and follow flagger instructions. Flaggers will be present when construction traffic is active. 
• Cyclists, please go slow and exercise caution on the trail spur. There may be large moving machinery, equipment, rocks, debris, wet or slippery conditions on the trail. Alternatively, you may want to consider using the 7th St S entrance to the W&OD trail. 

January-February 2024 Update

In January and February, the contractor will be working on the following:

• New outfall construction: Excavating and installing pipe segments in the new outfall from Four Mile Run up to Sparrow Pond. A section of the W&OD trail will be closed to complete this work. See more on the W&OD trail detour above. 
• Most habitat structures have been installed, including turtle basking logs, root wad habitat structures, and poles for wood duck boxes. Wood duck boxes will likely be installed in late February or March. Once the outfall is completed, work will resume on the remaining pools.
• Large equipment may be coming through the neighborhood during work hours. S Park Drive neighbors, we appreciate your patience!

December 2023 Update

In December-January, the contractor will be working on the following:

• New outfall construction: Excavating and installing pipe segments in the new outfall from Four Mile Run up to Sparrow Pond. A section of Four Mile Run trail is currently closed to complete this work. 
• Stabilizing and seeding around the pools. The habitat structures have been installed, including turtle basking logs, root wad habitat structures, and poles for future wood duck boxes. Once the outfall is completed, work will resume on the remaining pools.
• Large equipment may be coming through the neighborhood during work hours. S Park Drive neighbors, we appreciate your patience!

November 2023 Update

In November, the contractor will be working on the following:

• Excavation and hauling sediment from the pond, working from the pavilion area toward the construction entrance. 
• Dump trucks carrying sediment are coming through the neighborhood during work hours. S Park Drive neighbors, we appreciate your patience! 
• Installing turtle basking logs and root wad habitat structures.
• New outfall construction: Excavating and stabilizing a trench from Four Mile Run up to Sparrow Pond to prepare for the new pipe. A section of Four Mile Run trail is currently closed to complete this work.

September-October 2023 Update

From mid-September to mid-October, the contractor will be working on the following:

• Completing the construction access path. Along the path you may notice the equipment wash area, which will help prevent sediment (and any weed seeds) from leaving the site.
• Tree removals to create space for the new sediment collection area and expanded pools.
• Large earth-moving construction equipment beginning the excavation phase in the pond area.
• New outfall construction: Excavating and stabilizing a trench from Four Mile Run up to Sparrow Pond to prepare for the new pipe. A section of Four Mile Run trail is currently closed to complete this work.  

August-September 2023 Update: Construction Begins

The construction contractor began site preparations and setup in late August. In August and September, the contractor worked on the following:

• Installing construction fencing and erosion and sediment controls,
• Building the construction access path next to the W&OD trail between S Park Drive and Sparrow Pond (see above for temporary noise disruption notice) 
• Installing the construction entrance,
• Tree removals to create space for the new sediment collection area and expanded pools.

After these site preparations were completed, the contractor planned to start excavating sediment from the pond and preparing for the outfall construction phase. To ensure safety during the sediment excavation, the observation deck has been fenced off from access. In order to install the new outfall pipe connecting Sparrow Pond to Four Mile Run, there will be 6-7 weeks of trail closure and detour on the Four Mile Run trail and afterwards on the W&OD trail. More details about this step to come in future updates.

June-July 2023 Update: Pre-Construction Meeting

We are now moving into the construction phase of the Sparrow Pond Restoration project, as the County Board approved the construction contract on June 10, 2023. Thank you to everyone who provided feedback during the engagement process.

We expect that site preparations and setup for construction will start in August. This is a multi-phase project and construction is expected to take up to 12 months. 

Thank you to everyone who joined us for the July 12 pre-construction meeting.

• See the July 12 pre-construction meeting slide deck(PDF, 5MB)
• View the meeting recording.

Please fill out the Sparrow Pond Feedback Form or email LWhitesell@arlingtonva.us:

• To receive monthly email updates through pond construction OR
• To provide feedback on updated educational signage for Sparrow Pond.  

Finally, thanks to all who were able to participate in the June 2023 and October 2022 native plant rescues.

Fall 2022 Update: Native Plant Rescue, Sanitary Sewer Relining, S Park Drive Trail

Thank you to volunteers who helped rescue native plants on October 25 from Sparrow Pond! We also rescued a box turtle, which will stay over winter at Long Branch Nature Center.

What about other animals? As heavy storms continue to bring silt into the pond, remaining water pools have filled in. Most turtles and other wildlife have already moved to other areas along Four Mile Run. (Did you know that letting animals decide when to move improves relocation success?) Once the project is complete, we look forward to drawing them back with deeper pools and good habitat!

Thanks to everyone for your patience with the Four Mile Run Trail detour in early October. The detour allowed for project-related relining of a sanitary sewer line. 

The Sparrow Pond Restoration Project process continues to move forward. Construction is expected to start in 2023. We are moving into the procurement stage of the project process. Once that is wrapping up, we will schedule a final meeting, likely in spring 2023.

The County will also address the gully erosion problems next to the S Park Dr. trail. The trail entrance will be adjusted to accommodate these improvements.

As part of the Sparrow Pond project, we will also install new educational signs at the viewing deck. The signs will highlight native plants, wildlife, wetlands, and other project information.

Spring 2022 Update: Soil Borings, Finalizing Design

Soil borings were conducted the week of April 11 to check the soil layers and anticipate the earthwork and backfilling that will be required during the pond restoration. The team had spotters in the front and back of trucks carrying equipment to ensure the safety of cyclist and pedestrian trail users. The S Park Dr trail entrance and W&OD trail sections remained open. 

A project update was sent out in April 2022. The Sparrow Pond project engineering details continued to be fine-tuned as we wrapped up the design work for the sediment collection areas, pools, outfall, and planting plan. In the coming months we will begin the permitting and procurement processes, the final stages for the pond design. A plant rescue and seed collection will be pland for fall 2022. Stay tuned for more information.

September 2021 Update:As part of the Sparrow Pond design planning process, County contractors needed to investigate utility locations. The S. Park Drive entrance to the W&OD trail was closed for two days in the September 15-30 timeframe to conduct the work. We apologized for the inconvenience and encouraged trail users to take the 7thSt S entrance to the W&OD trail for your recreational or bicycle commuting needs. Detour signage was posted.

Fall 2021 Update: Utility Investigations

As part of the Sparrow Pond design planning process, County contractors needed to investigate utility locations. The S. Park Drive entrance to the W&OD trail was closed for two days in the September 15-30 timeframe to conduct the work. We apologized for the inconvenience and encouraged trail users to take the 7th St S entrance to the W&OD trail for your recreational or bicycle commuting needs. Detour signage was posted.

Spring 2021 Update: Pond Leveler for Beavers and Safety

Spring 2021 Update: Due to concerns about the raised water levels and the W&OD trail and embankment, a pond leveler was installed in April 2021 to help keep water levels stable while allowing the beavers to continue in the pond area. See below for more information about beavers and the pond leveler. 

Thanks to all who attended the virtual Sparrow Pond community meeting on Thursday, February 4, 2021. To view the presentation PDF and recording, please see the meeting materials in the table below.

* * * * *

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.