Dead Run Segments 2/3 Stream Restoration Project Public Meeting

A Fairfax County, VA, publication
Department of Public Works and Environmental Services
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Dead Run Segments 2/3 Stream Restoration Project
Public Meeting
Dolley Madison Library
June 9, 2015

Dead Run Segment 2/3 Stream Restoration Project
Stormwater Planning Division
Meeting Outline
2
• Project extent and timeline
• Response to issues raised
• Next steps
• Outline of potential design refinements
• Questions and answers
• Walk to site

Project Limits
3
Segment 2 – McLean
Central Park
• 800 Linear Feet
• Completely in Park
• Starts below previously
restored section near
library
Segment 3 – Dead Run
Stream Valley Park
• 1,500 Linear Feet
• Extends to Churchill Road
• Residential lots along
Elizabeth Drive and Carol
Rayes Street

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
4
http://www.fairfaxcounty.gov/dpwes/watersheds/

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
5
http://www.fairfaxcounty.gov/dpwes/stormwater/
projects/project_list.htm

Stormwater Program Regulatory Drivers
• National Pollutant Discharge Elimination System (NPDES)
• Virginia Stormwater Management Program (VSMP)
– Municipal Separate Storm Sewer Permit (MS4)
– 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
6

Dead Run– Stream Conditions
7

Dead Run– Stream Conditions
8
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 Resource Monitoring
• http://va.water.usgs.gov/fairfax/

Dead Run Stream Restoration
Project Benefits and Goals:
• Improve water quality
– Reduce sediment and nutrient loads
• Stabilize stream banks
– Reduce stream bank erosion
– Protect property
– Reduce tree loss
• Improve aquatic habitats
• Restore and enhance vegetated stream
buffer (riparian corridor)
Others:
• Reduce frequent flooding
9

Project Time Line
10
• Project initiated: Fall, 2013
• Surveys and assessment completed: Winter, 2013
• Pre-concepts submitted: April, 2014
• First public meeting: April 23, 2014
• Field walk with FCPA, MTF, Urban Forestry: August 15, 2014
• Pre-concept revisions to minimize tree loss completed: February, 2015
• Second public meeting: February 18, 2015
• Revised concept plan with alternative access options for Segment 3
completed: May 12, 2015
• First field walk with community: May 19, 2015
• Second field walk with community: June 9, 2015

Next steps: Task Force
• We recommend that a citizens task force (“Stream Team”) be convened in
coordination with Supervisor Foust’s office.
– The task force would be actively involved in revising the current concept plan to make sure
it is acceptable to the community:
– Clearly understand community goals and expectations
– Work with the design team to incorporate the community goals and establish a timeline
– Be able to convey the details of design constraints and trade-offs to the community
– Attend design charrette meetings
– Perform detailed review of concept plan revisions to make sure it meets the community
goals before it is presented to the wider community
– Recommend up to 10 representatives from the community
• We will continue to receive comments on the current concept through July 31st.
• We anticipate the task force will be convened by June 30th, and we will schedule a
kick-off meeting with the task force in early July.
11

Next Steps With Target Dates
12
• Work with task force to develop final concept and publish to website -
September, 2015
• Community meeting to present final concept - October, 2015
• Continue to work with task force to develop 95 percent design plans, and
complete permitting - January, 2016
• Final design phase public meeting - Spring, 2016
• Final plan authorization and bidding phase – To be determined based on
funding and approved budget
• Target is late spring/early summer, 2016
• Sequence with Dead Run Segment 1 (Dominican Retreat)
• Pardon Our Dust meeting with residents and contractor before issuing
construction notice to proceed.

Response to Issues Raised – Tree and Canopy Loss
13
-Proposed removal of more than 250 trees from McLean Central Park, including about 100 of the
park's largest trees.
-Proposed removal of virtually all other growth in a wide swath along the creek from Churchill
Road to Elizabeth Drive.
Current concept plan:
• 88 greater than 12 inch
trees, up to 10 for access,
23 are at risk.
• 133 6 to 12 inch trees, up
to 20 for access, 28 are at
risk.
• Approximately 20 percent
of trees proposed for
removal are at risk.
• Estimated canopy loss is
approximately 11 percent
of area shown in red.

Response to Issues Raised – Flash Flooding
14
-Failure to address a related and major park problem: flash flooding from stormwater
runoff that flows into the creek.
Tradeoff: Reduce channel size (to the low end of the range that still provides for a stable stream) and reduce tree
impacts, but the reduction in flood levels will be smaller. If we continue to realign the channel away from lots
(again, within an acceptable range), this will impact more trees.

Response to Issues Raised – Replacement Plantings and Trail Closure
15
- Lack of provisions made by the county to maintain or protect replacement plantings
from failure or encroachment of invasive species after the project is completed.
This will be considered and made part of the final plan. We will work with
the Park Authority and homeowners to create a final maintenance and
invasive plant control plan for the reforestation measures in the park.
- Closure of large sections of the park and trail for approximately 9 to12 months.
This is inaccurate. We will try to keep the trails open – again this is a
tradeoff. We can reduce the access impacts by using the trail but there will
be some work-hour closures of the trails if we opt to use the trails for
access. Temporary trails will be part of the project and we will work with
the Park Authority to maintain access into the park provided by trails.

Response to Issues Raised – Public Notification
16
--Woefully inadequate notification of the public about this project, its scope, and
impact on the community; there has been no visible signage in the park that would
notify park users.
We recognize that our standard public notification process was inadequate. The Park
Authority has provided us with templates and examples of their public notification
process for the park master planning process, and we will follow the same procedure
for notification. This includes:
- Significantly expanding the area where meeting notification postcards/letters are
sent.
- Posting signs in the park about upcoming meetings.

Response to Issues Raised – Water Quality Benefits
17
- Insufficient evidence that this project, given the extensive damage it will do to the
existing park environment, is the best way to achieve the proposed goals. In fact, no
estimate has been released of how much the water quality will improve over what
period of time.
A summary of this information was provided at the February meeting:
• Chesapeake Bay expert panel protocols used for estimating stream restoration
nutrient credits.
• For Total Phosphorus (TP), as an example, the estimated reduction in loadings as a
result of the proposed stream restoration for Segments 2/3 ranges from 0.063 to
0.261 pounds per linear foot per year (lbs/LF/yr.)
• This compares to a ‘default’ rate of 0.068 lbs/LF/yr. The high end of the estimated
load reduction is 3 times the default rate.
• Total annual estimated reduction in erosion for Segment 2/3 is between 783 to
1,500 tons/year and the estimated reduction in TP loading is between 190 and
788 lbs/year

Response to Issues Raised in Petition: Projected Water Quality
Improvements
18
0
1
2
3
4
5
6
400 600 800 1200 2200
Numberofprojects
$/ft
Streams - Unit Cost
Mean = $753/ft , Median = $601/ft
• Using the mean unit cost $753/ft, the cost per unit pound of annual TP reduction ranges
from to $3,000 to $12,000

Response to Issues Raised in Petition: Projected Water Quality
Improvements
19
Estimated range for proposed Dead Run Segment 2/3 restoration:
$3,000 - $12,000 $/lb TP/yr
Practices Number
Installed TP TN TSS
Stream Restoration 10 $ 25,583 $ 2,812 $ 13
Infiltration Swales & Trenches 3 $ 33,583 $ 5,765 $ 204
Pond Retrofits 32 $ 35,908 $ 7,928 $ 183
Soil Compost Amendment 9 $ 120,164 $ 16,797 $ 781
Dry Swales 7 $ 132,423 $ 22,732 $ 803
Bioretention (Rain Gardens) 18 $ 168,973 $ 28,935 $ 1,026
Pervious Pavement 4 $ 198,624 $ 33,631 $ 1,211
Capital Cost ($/lb/yr)

Additional Issues
20
- Use smaller equipment to minimize impacts
It is possible to write limitations on equipment in the bid documents as a special
condition, but potential problems include:
• Fewer bidders (possibly none)
• Significantly higher cost
• Significantly longer timeline
To reduce impacts we will consider/evaluate:
• Access alignments that minimize tree disturbance
• Design revisions that meet the overall goals but have less impact on trees
• Equipment used by stream restoration contractors e.g. track equipment has less
compaction and other impacts and allows them to work in wetter areas.
• Contractors generally use timber matting to further reduce soil compaction to
protect tree roots.

Equipment Used During Construction
21

Equipment Used During Construction
22

Churchill Road Bridge Flooding
23
• VDOT inspection reports indicate no deficiencies with the bridge.
• No current or future project is planned for the bridge.
• Not subject to frequent closures because of overtopping.

Churchill Road Bridge Backwater Area
24

Response to Issues – Task Force Recommendation
25
Therefore, we ask that Fairfax County:
1. Develop a new, much less invasive and impactful approach in order to preserve our park.
2. Change and significantly extend the entire timetable for the new project to provide full opportunity for
public response.
3. Provide widespread notification, including visible signage in the park, that would notify park users and
the community at large about the full scope of the new project proposal, its impact on the park, and
flooding.
- We recommend that a citizen task force (“Stream Team”) be convened by
Supervisor Foust’s office.
- The task force would be actively involved in revising the current concept plan to
make sure it is acceptable to the community:
- Clearly understand community goals and expectations
- Work with the design team to incorporate the community goals and establish a timeline
- Be able to convey the details of design constraints and trade offs to the community
- Attend design charrette meetings
- Perform detailed review of concept plan revisions to make sure it meets the community
goals before it is presented to the wider community
- Recommend approximately 10 representatives from the community

Northern Virginia Stream Restoration Bank
26

Northern Virginia Stream Restoration Bank
27

1Access Options
2Options for Refining the Design

1Access Options
• Alternative 1 Approach
• Proposed some access along the left bank of the stream through
Reach 3 adjacent to Elizabeth Dr.
• Alternative 2 Approach
• Proposed access within the Park only, along the sanitary sewer
easement and two sections of trail. No access on private properties.
• Additional alternatives Explored
• Access along sanitary sewer easement and trail.
• Selecting route that has least amount of tree impacts.

2 Design Refinement
• Options for Refinement of the
Design
• Smaller Channel Cross-section in specific
areas
• Transition from smaller to larger channel sections in areas,
where possible
• Opportunities to save trees
• Still focus on less frequent storm events and
improving the impacts of flooding especially
in the Segment 3 Upper area
• Maintain overall channel stability

2 Design Refinement
Pre/Post Comparison – Existing Section 1355
2 year flow out of banks
• Existing Conditions Analysis

2 Design Refinement
• Typical Channel Segment Upper,
~90 SF Area

2 Design Refinement
• Nested Channel Segment Upper,
~60 SF Area

2 Design Refinement
• Comparison

Stormwater Management
Stream Buffer Restoration Potential
37

Chesapeake Bay Preservation Ordinance
Resource Protection Area (RPA)
38
http://www.fairfaxcounty.gov/dpwes/environmental/cbay/

Stream Buffer Existing Conditions
39

Stream Buffer Restoration Potential
40
Segment 3 Stream Buffer Concept
Left Bank Left Bank Residential Residential
35 foot 50 foot 35 foot 50 foot
Area (Acres) 1.14 1.55 0.46 0.87
Canopy Trees 114 155 46 87
Understory Trees 229 310 92 174
Shrubs 1,246 1,690 501 946
Estimate tree and shrub plantings for Segment 3: Left Bank Only

Stream Buffer Restoration - Example
41
Typical Planting Area
County Staff will
coordinate with
individual
homeowners on
plant selection and
placement on their
properties
Buffer Parameters
35’ Minimum from
edge of stream
bank
50’ Offset optional
Plant density
determined by
Chesapeake Bay
Preservation
Ordinance
Dense planting will
provide privacy
screening and help
mitigate tree loss

42
Shrub Layer
Typical Shrub
Species
Spicebush
American
Elderberry
Witch Hazel
Winterberry Holly
Silky Dogwood
Button Bush

43
Understory Trees
Typical Understory
Species
Sweetbay Magnolia
Eastern Redbud
American
Hornbeam
Hazel Alder
Slippery Elm
Sassafras

Stream Buffer Restoration
44
Canopy Layer
Canopy
Tree
Evergreen
Understory
Tree
Deciduous
Understory
Tree
Shrub
Typical Canopy
Tree Species
Sugar Maple
River Birch
American Basswood
Common Persimmon
Swamp White Oak
Pin Oak
Willow Oak
Black Gum

Next Steps: Task Force
45
- We recommend that a citizens task force (“Stream Team”) be convened
by Supervisor Foust’s office.
- The task force would be actively involved in revising the current concept
plan to make sure it was acceptable to the community:
- Clearly understand community goals and expectations
- Work with the design team to incorporate the community goals and establish a
timeline
- Be able to convey the details of design constraints and tradeoffs to the community
- Attend design charrette meetings and participate in field reviews
- Perform detailed review of concept plan revisions to make sure it met the
community goals before it is presented to the wider community
- Recommend approximately 10 representatives from the community
- We will continue to receive comments on the current concept through
July 31st.
- We anticipate the task force will be convened by June 30th, and we will
schedule a kick-off meeting with the task force in early July.

Next Steps With Target Dates
46
• Work with task force to develop final concept and publish to website in
September, 2015
• Community meeting to present final concept in early October, 2015
• Develop 95 percent design plans, permitting by January, 2015
• Final design phase public meeting, early spring 2016
• Final plan authorization and bidding phase – To be determined based on
funding and approved budget
• Target is late spring/early summer, 2016
• Sequence with Dead Run Segment 1 (Dominican Retreat)
• Pardon Our Dust meeting with residents and contractor before issuing
construction notice to proceed.

Additional Information
For additional information, please contact
www.fairfaxcounty.gov/dpwes
Stormwater Planning Division 47
Dipmani Kumar, P.E., CFM
Project Manager
703-324-5500, TTY 711
dkumar@fairfaxcounty.gov

Dead Run Segments 2/3 Stream Restoration Project Public Meeting

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