This project will restore physical and ecological functions of the stream and improve water quality in the Accotink Creek Watershed.

1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
LONG BRANCH TRIBUTARY @ LONG BRANCH
FALLS PARK STREAM RESTORATION PROJECT
PROJECT PLAN UPDATE
(CONCEPTUAL)
JANUARY 20, 2016

2. Stormwater Planning Division
Agenda
• Project overview / Progress
• Existing conditions
• Summary of concept design
• Key plan elements
– Construction access
– Proposed cross sections
– Grading plan and longitudinal profile
– Trees – tree removal and preservation
– Floodplain – existing and proposed condition
• Timeline/Next Steps
2

3. Stormwater Planning Division
Project Overview/ Progress
3
• Restoration of about 600 linear ft. of main channel and 200 linear
ft. of small outfall channel totaling ~ 800 ft.
• Project Limits:
– Main Channel: D/S of rock outcrop near VDOT culvert @ King
David Blvd to a stable point u/s of culvert @ Windflower Lane
– Tributary channel: D/S of Pipe outfall at Colt Ln. to the
confluence with main channel
• The survey completed September 2015
• A preliminary concept plan was completed showing major design
elements in November 2015
• Design review team: County, Park Authority & representatives
from the community

4. Stormwater Planning Division
• Concept design review meeting completed on December 15,
2015 with a field walk on December 9, 2015.
The meeting reviewed the following:
– Access and staging
– Alignments
– Tree condition/Impacts
• Concept plan revision - completion January 2016
• Pre-final design meeting: February 2016
4
Project Overview/ Progress (contd.)

5. Stormwater Planning Division 5
Project Map
Restoration
Starts
Restoration
Ends
Outfall
Restoration
Starts

6. Stormwater Planning Division
Existing conditions
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7. Stormwater Planning Division
Existing conditions (cont’d)
7

8. Stormwater Planning Division
Final Rendering
8

9. Stormwater Planning Division
Construction access
9

10. Stormwater Planning Division 10
Longitudinal Profile of the Main Channel

11. Stormwater Planning Division
Longitudinal Profile of the Tributary
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12. Stormwater Planning Division
Tree removal and preservation plan
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13. Stormwater Planning Division 13
Tree removal and preservation plan

14. Stormwater Planning Division
100 -Year floodplain
14

15. Stormwater Planning Division
Proposed channel cross-sections
15

16. Stormwater Planning Division 16
Existing Conditions Cross Section

17. Stormwater Planning Division 17
Proposed Conditions Cross Section

18. Stormwater Planning Division
Timeline and next steps
18
• Concept revision - January, 2016
• Pre-final design meeting - February, 2016
• 95% design - March, 2016
• 95% design review meeting - April, 2016
• Design completion - May, 2016
• Construction - Currently funded for
design only
• Construction cost: estimated ~ $450K
Note: Invasive treatment work will be done sometime in the spring if the
project receives funding for this year’s construction. If not, the treatment
will be done prior to construction once a date is set.

19. Additional Information
For additional information, please contact
www.fairfaxcounty.gov/dpwes
Stormwater Planning Division 19
Sajan Pokharel
Ph.: 703-324-5687
Email: Sajan.Pokharel@fairfaxcounty.gov