Donaldson Run Stream Restoration Tributary B

Location

Donaldson Run watershed in north Arlington., Arlington, VA 22207  View Map

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Status

Construction

Donaldson Run - Before

Location

Donaldson Run watershed in north Arlington.

View Map

Status

Construction

Construction Activity Updates

  • The trail re-opened the weekend of July 4th.  The contractor is repairing the sidewalk and ADA access ramp and completing cleanup of the staging area.

  • For the weeks of June 13 and June 20:  Complete the trail repair and trail drainage work above the pedestrian bridge, plant trees and shrubs and install deer protection above pedestrian bridge, and placement of topsoil, matting and seeding with native seed mix. Complete sidewalk repair and cleanup of staging area.

    For the weeks of May 30 and June 6:  Continue trail repair and trail drainage work above the pedestrian bridge, plant trees and shrubs and install deer protection above pedestrian bridge, and placement of topsoil, matting and seeding with native seed mix

  • For the weeks of May 9th and 16th:  The crew will add topsoil, matting and seeding, and complete Step Run 22.  They will plant perennial plants below the pedestrian bridge, and remove the access road above the pedestrian bridge, repair the trail and install under trail drainage. They may begin planting of trees and shrubs above the pedestrian bridge.

  • For the weeks of April 26 and May 2nd:  The crew will complete the trailside stacked stone wall.  Tree and shrub planting will occur below the pedestrian bridge and in select locations above the pedestrian bridge.  Completion of Step Run 22 and Step pool 15 in the stream at the pedestrian bridge and removal of the temporary stream crossing is likely to occur.

  •  For the weeks of April 11th and 18th: The crew will continue work on the trailside stacked stone wall. The crew will work on access road removal, trail repair, soil stabilization and seeding below the pedestrian bridge. 

  • For the weeks of March 28th and April 4th:   The crew plans to complete Step Run 22 and Step pool 15 in the stream at the pedestrian bridge - this work is in the vicinity of the contractor’s temporary stream crossing.  The contractor is likely to complete tree removal, access road removal and seeding below the pedestrian bridge, and may begin restoring the trail below the pedestrian bridge.  The stacked stone wall on the right (trailside) bank has not been constructed to enable stream access, but the crew may begin construction this wall.

  • For the weeks of March 14th and March 21: The contractor will continue working instream below the pedestrian bridge. They will work downstream from Step pool 21 to the confluence with Tributary A.

  • For the weeks of February 28th and March 7th: The contractor will continue working instream below the pedestrian bridge. They intend to start at Step pool 20 and work upstream to Step pool 18, then work downstream from Step pool 21 to the confluence with Tributary A.  The tree removal intended to occur during the past two weeks had to be rescheduled and is likely to occur the week of Feb 28. Limited tree removal will occur, including snagging (cutting a tree to ~20 feet above ground to preserve the soil stability and habitat) of one dead tree. 
  • Weeks of February 14th and 21st:  Crew 1 will finish instream work above the pedestrian bridge (step runs 10 and 11). They will begin instream work below the pedestrian bridge.  Limited tree removal will occur, including snagging (cutting a tree to ~20 feet above ground to preserve the soil stability and habitat) of one dead tree. 
  • Weeks of January 31st and February 7th:  Crew 1 will work in-stream above the pedestrian bridge (Step Runs 8-11) and Crew 2 will work in-stream below the pedestrian bridge (Step Pools 16-18).  

  •  Week of 1/17 and 1/24. Crew 1 will work in-stream on Step Run 6 with the intent to finish in-stream work above the pedestrian bridge, excepting the imbricated wall on the right bank.   Crew 2 will work in-stream below the pedestrian bridge.

  • Weeks of 1/3 and 1/10 - Crew 1 continued stream construction including Step Pool 4, Step Run 5 and began work on a step pool series above Step Run 6 on the left bank.  Crew 2 installed the two step pools on the left bank just above the pedestrian bridge.  Work below the pedestrian bridge included installation of the access road and tree removal. Crew 2 also worked on pipe extension and repair of the storm sewer outfall just below the pedestrian bridge.

  • Weeks of 12/17 and 12/24 - Crew 1 will work in-stream on step run 5 and step pool 5.  They will also begin work on the right bank stone wall.  Crew 2 will work on step pool 15 through step run 22.  They will continue installing the deck mat access road below the pedestrian bridge. A tree crew will undertake tree removal below the pedestrian bridge. 

  • Weeks of 12/3 and 12/10 - Crew 1 will continue to work in-stream on Step Runs 3-4 and Step Pool 3. Crew 2 will work on the last four structures above the pedestrian bridge (Step Pools 14-15 and Step Runs 21-22), and the remaining in-stream work above the pedestrian bridge.  Survey work, installation of tree protection including the deck mat access, and tree removal will also occur below the pedestrian bridge.

  • Weeks of 11/22 and 11/29 - Crew 1 completed construction of the stone wall on the left bank downstream from the outfall.  Crew 1 then worked on several in-stream tasks in this same area, completing  Step Pools 1-3, and Step Run 1. They also worked on encasement of a private sanitary connection that crosses the stream.  Crew 2 worked on in-stream structures above the pedestrian bridge (Step Pool 12-13 and Step Run 19-20). They installed a new manhole and completed the storm sewer outfall on the right bank adjacent to these structures.
  • Weeks of 11/8 and 11/15 - Crew 1 will continue work on the stacked stone wall just downstream of the N. Upton Street outfall. They are likely to complete the wall on the left bank and progress to the right bank.  Crew 2 will continue in-stream work above the pedestrian bridge. They are likely to complete Step pool 12 and Step Runs 19 and 20.
  • Weeks of 10/25 and 11/1 - Crew 1 completed the work to extend the outfall at N. Upton St, and began construction of the stone wall on the left bank downstream from the outfall.  Crew 2 worked on in-stream structures above the pedestrian bridge (Step pool 11 and Step Run 18) and planted annual rye as temporary stabilization on the restored stream banks.
  • Weeks of 10/11 and 10/18 - work included in-stream work building step pools downstream of the water main repair, and initiation of work to install storm sewer pipe and extend the outall from N. Upton St. 
  • The conflict with the water main has been resolved. In order to protect both the water main and the sanitary sewer, the contractor will extend the outfall from N. Upton St slightly downstream.   For the weeks of September 27th and October 4th, work will include in-stream work downstream of the water main repair (through at least step pool 11) and possible initiation of work to install storm sewer pipe and extend the outfall.
  • For the weeks of September 13 and 20th, stream work will begin in the area downstream of the water main repair and storm sewer upgrades will be completed upstream of the pedestrian bridge.
  • For the weeks of August 30th and September 6th, work will include storm sewer upgrades on both sides of the stream. 
  • For the weeks of August 16th and 23rd - The construction schedule has been adjusted since the prior update.  Upcoming work will include tree removal above the pedestrian bridge, installation of the temporary stream cr, Storm sewer upgrades on both sides of the stream.
  • For the weeks of August 2nd and August 9th, work will include the installation of the stone walls and step pools closest to N. Upton St.
  • For the weeks of July 19th and 26th, work will include placement and inspection of the remaining tree protection, replacement of the storm sewer pipe and outfall at the end of N. Upton Street, initial work on the stone walls just downstream of the outfall, and temporary sidewalk installation at the corner of N. Upton Street and N. Vermont to complete the pedestrian construction detour

 

 

 

 

 

 

View some before and after pictures of the stream(PDF, 23MB)

As a reminder, the Zachary Taylor hike-bike trail along Donaldson Run Tributary B is closed during construction. For safety, please stay outside of the orange construction fence even when the contractor is not actively working.

100% Plan Documents

About the Project

Donaldson Run has been impacted by stormwater runoff, causing excessive erosion along the stream channel. A technique called “natural channel design” will be used to create a new stream channel that can better manage the runoff it receives from the surrounding land.  This method uses step pools, floodplain reconnection and meanders to help reduce the energy of the flow.

The Tributary B stream restoration approach is affirmed by design professionals, confirmed by peer review, and approved by regulatory agencies. EPA’s Chesapeake Bay Program considers urban stream restoration a best management practice to restore the Chesapeake Bay.

In 2006, the County completed a successful stream restoration of Donaldson Run’s Tributary A.   This restoration has protected the sanitary sewer line, reduced erosion and reduced stream pollution since 2007.  The photos at the top right of this page show before and after pictures of the stream restoration.

The stream restoration of Tributary B will:

  • Protect the 30” water main and sanitary sewer line. The water main within the stream valley serves 20,000 residents. Erosion in the stream valley has uncovered the water main, twice requiring emergency stabilization work.  This infrastructure was not designed to be exposed and as a result is currently more prone to damage and breaks. The project will support and protect these pipes.
  • Help the County meet its regulatory requirements to reduce nitrogen, phosphorus and sediment pollution. The County’s MS4 Permit requires reductions in nitrogen, phosphorus and sediment pollution. Stream restoration projects, like Tributary B, are especially effective tools to address phosphorus and sediment pollution. Arlington’s pollution reduction efforts are a part of the larger Chesapeake Bay cleanup effort.
  • Improve the long-term health of the stream valley forest. The stream erosion has undermined and killed trees along the stream, and more will be damaged unless the stream valley is restored.  Twenty trees have been lost in the past 2 years due to stream erosion and storm damage.  The restored stream channel will be stable, and, as a result, the remaining trees and new trees planted after restoration will be protected.   Over 300 new trees will be planted as part of the project.  
  • Restore native vegetation to the Tributary B stream valley. The area surrounding Tributary B is overrun with invasive, nonnative plants such as kudzu, porcelainberry, and English ivy. The area will be replanted with native plants that support local wildlife.
  • Protect the multi-use trail. Erosion is threatening the trail in several places. This is particularly noticeable in the section that is close to the confluence with Tributary A.

Design alternatives have been suggested to stabilize the stream in its current configuration. Learn why stabilizing the stream in its current configuration isn’t effective.

Why doesn’t the County do stormwater management upstream of Donaldson Run to reduce stormwater runoff, instead of doing stream restoration?

The County is doing both – adding new stormwater management facilities in the watershed, as well as restoring streams. The Stormwater Master Plan included a study 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 can’t 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?   

Due to the extremely tight work area, the impact that heavy equipment will have on the critical root zone of trees, and the fact that some of the trees are compromised due to stream bank erosion, some trees will be lost as a part of the construction process. Trees that are lost will be replaced following construction.

  • Two tree inventories were completed for this project. The first in 2010 and the second in 2015. For each inventory, urban foresters surveyed, measured, and assessed the condition of all of the trees in the project area.
  • 83 trees will be removed as a result of the project.  20 trees within the project area have been lost in the past 2 years from stream erosion and storm damage.
  • 332 native trees, 180 shrubs, 200 live stakes (cuttings that will grow into trees), and more than 4000 herbaceous plants will be planted as part of the project.   The planting contract includes a 5 year warranty on the plants and invasive plant control.

Why doesn’t the County use a wood based stream restoration method?

Staff reviewed the suggestion that a wood-based bank stabilization/armoring would present an effective and cost-efficient method for Tributary B.  Staff reached out to a firm with significant experience in this technique, which uses trees adjacent to the stream to build stability structures.  Because of the steep topography and severe erosion in the Tributary B valley, a large number of these structures would be needed, and significantly more trees would be removed to build these structures than the trees that will be removed for the project as currently designed. It is also a serious concern that this approach would be less enduring for the long-term as tree material degrades in an alternating wet and dry urban stream environment— reducing project integrity over time.

Public Process

Date Location Meeting Materials
June 25, 2021 N. Upton St Pre-construction Resident Meeting
February 5, 2020 Donaldson Run Civic Association Meeting - Taylor Elementary School
April 27, 2017 Urban Forestry Commission Meeting
November 9, 2016 Donaldson Run Civic Association
April 18, 2012 Donaldson Run Civic Association
June 2, 2011 Donaldson Run Advisory Group Meeting
Feb. 23, 2011 Donaldson Run Civic Association
Nov. 20, 2010 Donaldson Run Community Stream Walk– 60% Design Review
June 23, 2010 Community Meeting
Dec. 2, 2009 Donaldson Run Civic Association
Nov. 14, 2009 Donaldson Run Community Stream Walk
Nov. 5, 2009 Donaldson Run Advisory Group Meeting
December 2007 Neighborhood Conservation (NC) Advisory Committee Meeting Funding approval.
2005 Donaldson Run Civic Association Votes taken to reaffirm the Tributary B stream restoration project as the neighborhood’s first-priority NC project.
September 2004 Donaldson Run Civic Association

Vote to designate the Tributary B project as the priority NC Program project (it was announced prior to the meeting that the vote would be taken).

Funding

More than 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 Program funding in 2001 to study Donaldson Run stream and identify potential stream improvements.

A stream restoration project was completed on Donaldson Run Tributary A in 2006. Before and after photos are in the image gallery. The Donaldson Run Civic Association was awarded an additional $350,000 in 2007 to restore Tributary B. Matching funds to construct the project will come from the Stormwater Fund.