A Fairfax County, VA, publication Department of Public Works and Environmental Services Working for You! Dead Run Stream Restoration Project Segments 2/3 – Final Concept Plan Community Meeting Dolley Madison Library May 4, 2016
Apr 13, 2017
A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Dead Run Stream Restoration ProjectSegments 2/3 – Final Concept PlanCommunity MeetingDolley Madison Library
May 4, 2016
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Meeting Outline
• Project Scope• Project Timeline• Background• Existing Conditions• Task Force and Community Involvement • Revised Final Concept Changes – Summary• Proposed Condition Renderings• Revised Final Concept Design Approach• Buffer and Riparian Corridor Restoration Plan• Next Steps• Q&A
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Dead Run Stream Restoration
Project Limits – Two Projects
Segment 2:McLean Central Park• 750 linear feet of main
channel and 560 feet of tributary channels
Segment 3:Dead Run Stream Valley Park• 1,460 linear feet of main
channel and 350 feet of tributary channels
Segment 1:Dominican Retreat• 1,500 linear feet of main
channel and 380 feet of tributary channels
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Dead Run Stream RestorationSegment 2 – McLean Central Park• 750 linear feet main
channel and 560 feet of tributary channels
• Completely in Park
• Starts below previously restored section near library
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Dead Run Stream RestorationSegment 3 – Dead Run Stream Valley Park• 1,460 linear feet of main channel
and 350 feet of tributary channels
• Extends to Churchill Road
• Residential lots along Elizabeth Drive and Carol Raye Street
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Dead Run Segment 2/3 Stream Restoration Project
Project timeline• Fall, 2013: Project initiated
• Winter, 2013: Surveys and assessment completed
• April, 2014: Pre-concepts submitted
• April 23, 2014: First public meeting
• August 15, 2014: Field walk with FCPA, MTF, Urban Forestry
• February, 2015: Pre-concept revisions to minimize tree loss completed
• February 18, 2015: Second public meeting
• May 12, 2015: Revised concept plan with alternative access options for Segment 3 completed
• May 19, 2015: Third public meeting and first field walk with community
• June 9, 2015: Fourth public meeting and second field walk with community
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Dead Run Segment 2/3 Stream Restoration Project
Project timeline• Community Stream Team – Task Force
• Held 4 meetings between August and December 2015
• Visited completed stream restoration sites
• Met with residents adjacent to project in March, 2016
• Revised final concept design completed in April, 2016.
Next Steps:
• Site visit with Community (May 19, 2016)
• Final design phase
• Coordination with task force and community
• Final construction documents and bidding
• Pardon our dust community meeting and construction
• Post-construction monitoring and maintenance
Stormwater Planning Division
Watershed Planning and Project Implementation
• Watershed Characterization– Water Quality Monitoring– Physical Stream Assessment– Land Use Change– Pollutant Loading
• Structural Project– 25 year plan
• Non-Structural Practices– Policy and Regulations
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http://www.fairfaxcounty.gov/dpwes/watersheds/
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Watershed Planning and Project Implementation
• Dead Run has a drainage area just over 3 mi2
• 24 priority projects identified in the watershed management plan• Pond retrofits• LID Stormwater Enhancements• Stream Restoration• Neighborhood Stormwater
Improvements
http://www.fairfaxcounty.gov/dpwes/stormwater/projects/project_list.htm
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Stormwater Program Regulatory Drivers
• National Pollutant Discharge Elimination System (NPDES)
• Virginia Stormwater Management Program (VSMP)– Municipal Separate Storm Sewer Permit (MS4)– Discharge from approximately 7,000 storm drain outfalls– Includes watershed planning and project implementation
• Total Maximum Daily Loads (TMDLs)– Chesapeake Bay– Local Streams– Establishes pollutant loading budget for a given impaired water
body to meet water quality standards
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Dead Run– Stream Conditions
http://www.deq.virginia.gov/Programs/Water.aspx
Stormwater Planning Division
Dead Run Segment 2/3 Stream Restoration Project
Existing Conditions - Biological Monitoring Data
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Dead Run– Stream Conditions
Fairfax County Annual Water Quality Report• http://www.fairfaxcounty.gov/hd/streams/strannualrpt.htm
Virginia Department of Environmental Quality • Water Quality Report (305b report)• http://www.deq.virginia.gov/Programs/Water.aspx
U.S. Geological Survey• Dead Run stream gage at Whann Avenue• Fairfax County Water Resources Monitoring• http://va.water.usgs.gov/fairfax/
Stormwater Planning Division
Dead Run Segment 2/3 Stream Restoration Project
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Dead Run Segment 2/3 Stream Restoration Project
Dead Run Stream Valley – A historical perspective
1937
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Dead Run Segment 2/3 Stream Restoration Project
Dead Run Stream Valley – A historical perspective
1954
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Dead Run Segment 2/3 Stream Restoration Project
Dead Run Stream Valley – Today
2015
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Dead Run Segment 2/3 Stream Restoration Project
Segment 2 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 2 Existing Conditions
Stream Bank Erosion and at Risk Trees
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
February 2012
July 2015
Trees along stream bank continue to fall and/or die
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
February 2012
July 2015
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Segment 3 Existing Conditions
Bridge at Churchill Road
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Dead Run Segment 2/3 Stream Restoration Project
On-line: Story Map of Existing ConditionsExisting conditions: http://arcg.is/1Y55MNj
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Summary of Task Force Comments and Concerns• Project Benefits • Design Approach • Tree Loss• Frequent Yard Flooding• Flooding at Churchill Road• Construction Equipment and Footprint • Trail Closures• Invasive Plant Management• Others
– Site restoration and maintenance– Stream conditions and erosion below Churchill Road
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Project Benefits
• Estimated annual erosion rates for Segment 2/3 based on field data is between 783 to 1,500 tons/year
Stream Bank Erosion Field Data• Chesapeake Bay Expert Panel protocols used for estimating stream restoration nutrient and sediment credits.
• Estimated reduction in Total Phosphorus loading is between 190 and 788 lbs/year
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Churchill Road Flooding
• VDOT staff attended last Stream Team meeting (December, 2015)
• VDOT inspection reports indicate no deficiencies with the bridge
• No current or future project planned for the bridge at this time
• Proposed stream restoration project includes removing sediment and debris upstream of the bridge and aligning channel with bridge abutments.
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Dead Run Segment 2/3 Stream Restoration Project
Churchill Road Bridge Backwater area
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Dead Run Segment 2/3 Stream Restoration Project
Summary of Plan Revisions – Tree LossTree Loss Summary
Date 6” to 12” 12” and Larger Total Trees at Risk
February 2014Not Surveyed
137 137
February 2015 110 110
May 2015
Alt 1 133 88 221
Alt 2 153 98 251
December 2015
Alt 1 76 72 148 48
Alt 2 81 72 153 45
Alt 1 and Alt 2 refer to access alternatives 1 and 2:Alt 1: Access road is closer to the stream for Segment 3Alt 2: Access road follows trail and utilizes cut-throughs for access to stream for Segment 3.
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Dead Run Segment 2/3 Stream Restoration Project
Summary of Plan Revisions – Tree Loss
• Total number of trees to be removed for project (148-153)
• Total number of trees within the LOD that were either dead or at risk (45-48) – approximately 1/3rd
• Reduction in tree loss impact as a result of design modification between May 2015 and December 2015:
• Alt 1 – 73 trees saved (33% reduction)
• Alt 2 – 98 trees saved (39% reduction)
• Existing trees have very little diversity with only 2 species making up the majority of trees: red maples and tulip poplars.
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Planting
• Proposed Planting Based on Alternative 1
• Approx. 250 trees 1 inch to 1.5 inch caliper size
• Approx. 500 trees that are 6 to 8 feet tall
• Approx. 2,600 shrubs
• All vegetation is native species and specifically selected for the stream corridor
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Dead Run Stream Restoration Project
Existing Park Conditions• Park Area = 33.25 acres• Tree Canopy = 27.45 acres
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Dead Run Segment 2/3 Stream Restoration Project
Summary of Plan Revisions – Area disturbed Total Acres* Woodland /
Open**May 2015
Alt 1 ~5.05 Acres 3.65Alt 2 ~5.15 Acres 3.75
December 2015 Alt 1 ~4.58 Acres 3.18Alt 2 ~4.72 Acres 3.32
*Excludes trail area, ** Excludes stream channel area and trail area
Conclusion Alt 2 access has slightly more disturbance and would close the trails for a longer period of time compared to Alt 1, and would likely necessitate the use of woodchip trails which would have additional impacts.
The overall area of disturbance has been reduced by 10% from May 2015. If the stream channel area (1.4 ac) is excluded (i.e only impacts to woodland/open areas considered), the actual AOD has been reduced by 11-13%
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Dead Run Segment 2/3 Stream Restoration Project
Summary of Plan Revisions – Channel Size
Segment 2 Upper Segment 3 Lower Segment 3
Existing channel size(SF) 59-82 57-113 62-70Proposed channel size (SF) 55-80 60-129 62-72
Proposed channel size is now comparable in size to the existing channel.
This channel was sized using natural channel design principles and represents a balance to minimize impacts but still provide long-term channel stability and water quality benefits.
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Summary of Plan Revisions – Floodplain and Drainage
• No change in 100-year or FEMA floodplain
• No rise certification• Improve drainage from
existing storm drains
Fairfax County 100-Year Floodplain
FEMA Special Flood Hazard Area
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 2
Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 2
Rendering of Proposed Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 3
Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 3
Rendering of Proposed Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 3
Existing Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions Renderings – Segment 3
Rendering of Proposed Conditions
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Conditions On-line Map Tour
http://arcg.is/1N4KSgq
Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Riparian Corridor Restoration Plan
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Existing vegetation baseline characterization
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Existing Vegetation classified into 5 major areas:
MCPP1: Gazebo area, Area near Martha Jane Street
MCPP2: Areas adjacent to Segment 2 and upstream of Segment 2.
MCPP3: Adjacent to Segment 3
MCPP4: Area to the right of trail along middle and lower Segment 3 (looking towards Churchill Road
MCPP5: Area to the right when entering park from Oak Ridge Avenue (near tennis courts)
Story Map: http://arcg.is/1TKK67P
Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Existing vegetation baseline characterization
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Dolley Madison Library Outfall before Restoration
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Existing vegetation baseline characterization
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Existing vegetation baseline characterization
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Divison
Existing vegetation baseline characterization
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Existing vegetation baseline characterization
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Elements of Riparian Corridor Restoration Plan
• Invasive Plant Management• Planting plan
– Inside and outside project limits within park
• Residential lots adjacent to stream
• Warranty requirements (2-years)• Long-term monitoring and
maintenance
Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Chesapeake Bay Preservation Ordinance Resource Protection Area (RPA)
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http://www.fairfaxcounty.gov/dpwes/environmental/cbay/
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Dead Run Segment 2/3 Stream Restoration Project
Proposed Planting
• Proposed Planting Based on Alternative 1
• Approx. 250 trees 1 inch to 1.5 inch caliper size
• Approx. 500 trees that are 6 to 8 feet tall
• Approx. 2,600 shrubs
• All vegetation is native species and specifically selected for the stream corridor
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Dead Run Segment 2/3 Stream Restoration Project
Next Steps
• Continue to work with residents to develop buffer enhancements on private lots adjoining Segment 3.
• Site visit (May 19, 2016) – trees to be flagged
• Final design phase and prepare construction documents
• Coordination with Task Force and community
• Bidding and contract award
• Pardon Our Dust Meeting
• Construction
• Post-construction monitoring and maintenance
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Next Steps: Site VisitSite Visit
• Date: Thursday, May 19, 2016
• Time: 6:30 – 8:00 pm
• Meeting Location: McLean Central Park - Pedestrian bridge crossing Dead Run near tennis courts
Meeting Location
Additional Information
For additional information, please contact
www.fairfaxcounty.gov/dpwes
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Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Dipmani KumarProject Manager