Donaldson Run Stream Restoration Tributary B : Green Buildings : Arlington, Virginia

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Donaldson Run Stream Restoration Tributary B

NOTE: The presentation from the June 23rd Meeting and a Meeting Summary is posted below.

View the Presentation from the June 23rd Project Update and Community meeting.
View the June 23rd Meeting Summary.

View answers to some recent questions received about the project.
View the 60% Design documents that will be presented at the meeting.

Project Background

Over 10 years ago, residents of Donaldson Run Civic Association were concerned about erosion in the stream, which degrades water quality and in-stream habitat, 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 recent 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.

Project Information

A Donaldson Run Tributary B Overview Presentation was given at the at Donaldson Run Civic Association Meeting on December 2, 2009.

In addition, conceptual designs (Part 1 and Part 2) were presented at the meeting.

A presentation to the Urban Forestry Commission was made on April 22, 2010, which contains some updated information about the project need, purpose, and concept designs.

A Presentation on the 60% Designs was given at a meeting on June 23rd.

View the 60% Design documents that were presented at the June 23rd meeting.

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.

Public Process and Schedule

The public planning and design process for the project began in 2004 with an announcement in the Donaldson Run Civic Association newsletter that a vote would be taken at the September DRCA general meeting to designate the Tributary B project as DRCA’s #1 Neighborhood Conservation Program project. A unanimous vote in support of the project occurred at the September 2004 meeting. Votes were also taken at two DRCA meetings during 2005 to reaffirm the Tributary B stream restoration project as the neighborhood’s first priority NC project.

The Neighborhood Conservation Advisory Committee approved $350,000 for the Tributary B stream restoration project in December 2007. Matching funds to construct the project will come from the County’s Stormwater Fund.

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.

The stream assessment and design process began in early 2009, with the following meetings occurring to report the results of the assessment and to present concept designs:

Donaldson Run Civic Association newsletter articles - 2009
Donaldson Run Advisory Group Meeting - November 5, 2009
Donaldson Run Stream Walk - November 14, 2009
Presentation at Donaldson Run Civic Association Meeting - December 2, 2009
DRCA/community meeting to review 60% Design documents, June 23, 2010

Future Meetings:

Stakeholder Advisory Group meeting, Fall 2010
Second Stream Walk, Fall 2010

100% Design Review
• Stakeholder Advisory Group meeting, Fall, 2010
• DRCA/community meeting, Fall 2010

Construction
Construction on this project is expected to take place in 2011.

Photos of Tributary A and Tributary B After Rain Storm


*Tributary A, Restored Reach*	*Tributary B, Unrestored Reach*
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.

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


Stream erosion is undercutting trees along the stream banks, impacting their health and causing some trees to fall into the stream and die.

	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.

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)


*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.

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.

AFTER RESTORATION:These pictures show the stream restoration in June of 2007, about on year after the project was completed.


*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.*