Environmental Services
Donaldson Run Stream Restoration Tributary B
| Project Update: View the 75% designs for the Donaldson Run Tributary B Stream restoration project. |
Project Background 
Over 10 years ago, residents of Donaldson Run Civic Association were concerned about erosion in the stream, which degrades the health of the stream and threatens nearby trees and trails. The Donaldson Run Civic Association applied for and received Neighborhood Conservation Funding (NCP) in 2001 to study Donaldson Run stream and identify potential stream improvements.
Stream restoration is a key component of the County's Stormwater Management program. Because of the amount of development in Arlington, our streams receive high levels of runoff when it rains. Stormwater runoff destroys habitat for stream organisms, erodes stream banks, and carries sediment and other pollutants downstream to the Potomac River.
A stream restoration project on Tributary A of Donaldson Run was completed in 2006. Find out more about the Tributary A project.
The Donaldson Run Civic Association was awarded additional NCP funding in 2007 to restore another tributary of the stream, Tributary B. This project is currently in the design stage. Find out more about Tributary B Project below.
Project Need
Why do a stream restoration project? Why not just leave the stream as it is?
Donaldson Run has been impacted by stormwater runoff, causing excessive erosion along the stream channel. There are several compelling reasons to do a stream restoration, sooner rather than later:
- Reduce sediment pollution. View storm photos illustrating sediment pollution. Sediment that erodes from the banks of Donaldson Run degrades the water quality in the stream, and added to the sediment eroded from urban streams throughout the area, also damages the Potomac River and the Chesapeake Bay. Sediment and the nutrients carried with it are pollutants that reduce dissolved oxygen, block sunlight from water, and smother aquatic life. For these reasons, the U.S. Environmental Protection Agency’s Chesapeake Bay Program has recognized urban stream restoration as a key component of the plan to restore the Chesapeake Bay watershed.
- Protect the sanitary sewer line. The stream erosion has uncovered the sanitary sewer line in several places, and even completely eroded beneath the sewer line in some locations. This sewer line was originally buried about three feet below the stream channel bottom, but the stream has eroded down several feet over the past 50 years. Exposed sewer lines along Donaldson Run have been broken several times in recent years, and such breaks have caused leaks of untreated sewage into the stream.
- Improve stream health. By creating a stable stream channel, the quality of the stream environment will be significantly improved. The excessive erosion and sediment deposition that currently degrade water quality will be reduced, and habitat for aquatic organisms will be greatly enhanced.
- Improve the long-term health of the stream valley forest. The stream erosion continues to undermine trees along the stream bank, and a substantial number of mature trees have fallen into the stream or across the trail in recent years. Many of the trees that will be removed by the restoration project are trees that are already undermined by existing stream erosion and are likely to fall or die. The restored stream channel will be stable, and, as a result, the remaining trees and new trees planted after restoration will be protected.
- Restore native vegetation to the Tributary B stream valley. The area surrounding Tributary B is overrun with invasive, non-native plants such as kudzu, porcelainberry, and English ivy. These plants choke out native vegetation, and do not support our local wildlife. Climbing invasive vines such as English ivy threaten the health of the trees as well.
- Protect the bike trail. Erosion is threatening the trail through the park in several places.
Why doesn't the County do stormwater management upstream of Donaldson Run to reduce stormwater runoff, instead of doing stream restoration? The County has begun a process to find locations to add stormwater management facilities in local watersheds. These watershed retrofits will slow down and treat stormwater runoff, which will help water quality in our streams in the long term. However, these retrofits cannot undo the damage that development and excessive runoff have already caused to local streams. Streams that have eroded down and widened in their channel will continue to do so, washing more sediment and pollution downstream, and threatening more trees along the stream channel.
Why do trees have to be removed to do a stream restoration project? Over time, Donaldson Run has eroded a deeper and wider channel than it had initially. To restore the stream, a new stream channel will be created, that is in balance with the flow of water from the watershed. The bottom of the stream channel is raised up to create a shallower channel, so that the stream can have access to a floodplain during higher flows, slowing down the flow of the water. Also step pools and a more natural curvature are created to help slow down the water and dissipate energy. Equipment is used to shape and create the new stream channel, and trees that are along the stream banks and within the new floodplain area must be removed. Over half of the trees that would be removed for this project are already undermined by stream erosion or are in poor condition.
Read some more Frequently Asked Questions about stream restoration.
View answers to some recent questions received about the Tributary B project.
Public Process and Schedule
- September 2004 - Donaldson Run Civic Association voted at general meeting to designate the Tributary B project as the priority Neighborhood Conservation Program project (it was announced prior to the meeting that the vote would be taken, in the Donaldson Run Civic Association newsletter).
- 2005 - Votes were also taken at two DRCA meetings to reaffirm the Tributary B stream restoration project as the neighborhood’s first priority NC project.
- December 2007 - The Neighborhood Conservation Advisory Committee approved $350,000 for the Tributary B stream restoration project. Matching funds to construct the project will come from the County’s Stormwater Fund.
- 2009 - Donaldson Run Civic Association newsletter articles
- November 5, 2009 - Donaldson Run Advisory Group Meeting
- November 14, 2009 - Donaldson Run Stream Walk
- December 2, 2009 - Presentation at Donaldson Run Civic Association Meeting
- June 23, 2010 - DRCA/community meeting to review 60% plans, Meeting presentation and summary are below
- November 20, 2010 - Donaldson Run Stream walk
- February 23, 2011 - DRCA meeting to review 75% plans
- June 2, 2011 - Donaldson Run Advisory Group Meeting
More than a dozen civic association newsletters have provided updates on the project since 2004, and separately, the project has been discussed by DRCA leadership and/or staff at more than a dozen civic association meetings since 2004.
A citizen advisory group has also been formed to advise the project team. This advisory group included several representatives from the civic association, and one representative from each of the Urban Forestry Commission, the Parks and Recreation Commission, the Environment and Energy Conservation Commission, and Arlingtonians for a Clean Environment.
Future Meetings:
Stakeholder Advisory Group meeting, March/April 2011
Project Information and Design
| Design Phases | Date |
Donaldson Run Civic Association Meeting on December 2, 2009 | |
View the June 23rd Meeting Summary | Community Meeting, June 23, 2010 |
| Donaldson Run Civic Association Meeting on February 23, 2010 | |
| Donaldson Run Advisory Group Meeting, June 2, 2011 |
For more information about this project, please contact Larry Finch of the Donaldson Run Civic Association at 703-528-6349, Jason Papacosma at 703-228-3613 or Aileen Winquist at 703-228-3610, both with Arlington County DES.
Photos of Tributary A and Tributary B After Rain Storm
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| These pictures were taken immediately after a thunderstorm on June 27, 2010. The difference in water quality between the restored reach, Tributary A, (left) and the unrestored reach, Tributary B, (right) is very clear. Significant amounts of sediment are being washed out of the unrestored branch of Donaldson Run. | ||
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| These pictures show where the the restored reach (Tributary A, left) of Donaldson Run, and the unrestored reach (Tributary B, right) flow together immediately after a thunderstorm on June 27, 2010. The difference in water quality between the restored reach and the unrestored reach is very clear. | ||
Photos of Tributary B Project Area
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| Stream erosion is undercutting trees along the stream banks, impacting their health and causing some trees to fall into the stream and die. | ||
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| In the photo above, the area to the right used to have a large tree, which was undermined by stream erosion and fell over. The tree on the left is now being undercut by the stream. In addition, the nearby bike trail is threatened by the stream erosion. | ||
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| Many invasive plants, such as kudzu, porcelainberry, and english ivy are present along Tributary B, overrunning the native shrubs and trees in the valley. This photo shows an invasive vine that has overgrown the trees and shrubs. | ||
Before and After Pictures of Tributary A (Completed Stream Restoration Project)
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| BEFORE RESTORATION: These pictures show Donaldson Run in Zachary Taylor park before the restoration project. Erosion endangers trees along the stream, causing many of them to fall over, and exposes sanitary sewer lines. | |
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| BEFORE RESTORATION: These pictures show some of the severe stream bank erosion, root exposure, and damage to trees along Donaldson Run. In the picture on the right, the sanitary sewer line (encased in concrete) is exposed. | |
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| AFTER RESTORATION:These pictures show the stream restoration in June of 2007, about on year after the project was completed. | |
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| AFTER RESTORATION:These pictures were taken during a rain event in April of 2008. The picture on the left shows some of the new meanders and the picture on the right shows some of the step pools. | |
ON THIS PAGE
Background
Project Need
Project Information
Public Process and Schedule
Photos of Project Area
