Fairfax County Stormwater Presentation for Penderbrook HOA February 18, 2013

1. Oakton Swim & Racquet Club DF9045A
Oakton Estates DF9045B
Penderbrook DF9045D
February 18, 2013
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2. Tonight’s Meeting Agenda
• Stormwater Planning Division
• Environmental Services
• Watershed Planning
• Stormwater Project Goals & Objectives
• Project Information, Examples
• Next Steps- Q/A
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3. MAJOR COMPONENTS OF FAIRFAX COUNTY’S
STORMWATER PROGRAM
• Conveyance Systems
• Dam Safety and Facility Rehabilitation
• Emergency and Flood Response Operations
• Stormwater Regulatory Program
• Streams and Water Quality
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4. STREAMS AND WATER QUALITY
STRUCTURAL PROJECTS
• Detention Basin Retrofits
• LID Implementation
• Outfall Improvement
• Stream Restoration
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5. Service Drivers
• Federal
– Clean Water Act of 1972
• Municipal Separate Storm Sewer (MS4) Permit
– Total Maximum Daily Loads (TMDL)
• Commonwealth
– Virginia Stormwater Management Act
– Chesapeake Bay Preservation Act
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6. Countywide Watershed Planning
NICHOL
SUGARLAND RUN RUN POND
BULL NECK RUN
BRANCH
SCOTTS RUN
DEAD RUN
WASHINGTON DULLES Town of TURKEY RUN
INTERNATIONAL AIRPORT Herndon
HORSEPEN
CREEK DIFFICULT RUN
PIMMIT RUN
Town of
Vienna Falls
Church FOUR MILE RUN
CUB RUN Arlington County
City of
BULL Fairfax
RUN
ACCOTINK
POPES CREEK CAMERON
City of
Alexandria
HEAD RUN
CREEK BELLE
Town of POHICK HAVEN
LITTLE ROCKY RUN Clifton
CREEK
WOLF
JOHNNY MOORE CREEK DOGUE LITTLE
RUN SANDY
CREEK HUNTING
OLD MILL BRANCH RUN CREEK
MILL
RYANS DAM Oc River
co BRANCH ac
om
qu
a n
Po t
OCCOQUAN R
iv
er
KANE CREEK
HIGH POINT
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7. Difficult Run Watershed
• Drains to the Potomac River and into
the Chesapeake Bay
• 58.3 square miles
To view the Difficult Run Watershed
Management Plan please visit:
http://www.fairfaxcounty.gov/dpwes/water
sheds/difficultrun_docs.htm
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8. Reasons for Countywide Watershed
Planning
To restore and protect the county’s streams, of which 80 percent are
categorized as being in “fair” to “very poor” condition
To help meet state and federal water quality standards by identifying
strategies to prevent and remove pollution
To support Virginia’s commitment toward cleaning up the Chesapeake Bay
To replace the outdated watershed management plans and incorporate the
use of new technologies
To take a comprehensive approach in addressing multiple regulations,
commitments, and community needs
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9. Stormwater Projects
Community Goals & Objectives
• Open lines of communication with communities.
• Educate on project objectives and goals.
• Continue to coordinate and share information with the
community.
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10. Ecological Goals & Objectives
• Establish an ecologically balanced system
• Remove undesirable plants and replace with native
vegetation
• Extend the stormwater flow path with retrofit features
• Slow down the velocity of runoff decreasing erosion
• Infiltrate more runoff to reduce the quantity of stormwater
runoff in streams which discharge to the bay
• Reduce future maintenance
• Reduce negative downstream impacts
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11. 11

12. Current Site Conditions
3-locations
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13. Oakton Swim & Racquet Club Existing Conditions
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14. Oakton Swim & Racquet Club Existing Conditions
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15. Oakton Swim & Racquet Club Existing Conditions
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16. Oakton Swim & Racquet Club Existing Conditions
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17. Oakton Estates Existing Conditions
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18. Oakton Estates Existing Conditions
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19. Oakton Estates Existing Conditions
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20. Oakton Estates Existing Conditions
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21. Penderbrook Existing Conditions
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22. Penderbrook Existing Conditions
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23. Penderbrook Existing Conditions
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24. Project Information
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25. Oakton Swim & Racquet Club Project Phase IA
(this project must be approved before the
Oakton Estates Project Phase IIA can proceed)
Proposed measures
• Install 3 rain gardens around the existing 3 drain inlets.
• In county easements only: use amended soils around the tennis courts and in other locations that
receive sheet flow and where acceptable.
• In county easements only: Install vegetated swales in areas that receive concentrated stormwater
runoff.
• Identify areas (amended soils and/or vegetated swales) that could be landscaped with native
plants and placed into a “do not mow” landscape feature.
• Add native seed mix to take areas out of the mowing cycle and let areas naturalize with native
plants where acceptable.
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26. 26

27. 27

28. Oakton Estates Project Phase IIA
Across the street from Phase IA
(cannot proceed without Phase IA)
Proposed measures
• Work only within the Oakton Estates property. Location of the work to be
from a point south of the rip-rap to the property line. Rip-rap to remain in
place. Work to include: raising the stream bed elevation, stabilizing the
stream bed profile with riffle grade control structures, install grade control
structures to stop the head cut, and stabilize the banks by sloping (Avoid
mature trees) and install native vegetation and soil stabilization matting.
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29. 29

30. 30

31. Penderbrook Project Phase IB
Proposed measures
• Remove concrete ditch and install water quality improvements: extend the flow path, use micro-
pools, and plant native vegetation.
• Relocate spillway to Waples Mill side and plant screening vegetation on the Center Way side.
• Provide grade control and bed material at the mouth of the incoming channel to avoid potential for
head cutting due to removing the trickle ditch and changing elevations within the basin.
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32. 32

33. 33

34. 34

35. Examples
Completed Projects
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36. Low Impact Development
Walt Whitman Middle School – Rain Gardens
Area Treated Phosphorous Nitrogen Removal Sediment Removal
(acres) Removal (lbs/yr) (tons/yr)
(lbs/yr) 36
1.29 2.2 4.7 0.6

37. Low Impact Development
Sherwood Library - Permeable Pavers & Rain Garden - Now
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38. Outfall Restoration
Big Rocky Tributary – Before & After
Drainage Area Phosphorous Nitrogen Removal Sediment Removal
(acres) Removal (lbs/yr) (tons/yr)
(lbs/yr) 38
96 4 68 1

39. Outfall Retrofits
Sheffield Hunt– Before & After
Drainage Area Phosphorous Removal Nitrogen Removal Sediment Removal
(acres) (lbs/yr) (lbs/yr) (tons/yr)
29.25 63.92 188 145.7
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40. Detention Basin Retrofits
Foxfield Section 13 - Before & After
Area Treated Phosphorous Removal Nitrogen Removal Sediment Removal
(acres) (lbs/yr) (lbs/yr) (tons/yr)
111 49 383 14
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41. Detention Basin Retrofits
Cinnamon Oaks Outfall into Basin - Before & After
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42. Pond Retrofits
Sequoia Farms - Before & After
Area Treated Phosphorous Removal Nitrogen Removal Sediment Removal
(acres) (lbs/yr) (lbs/yr) (tons/yr)
92.25 50.48 361.16 3.88
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43. Examples
Additional Projects
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44. Stream Restoration
Dead Run – Before & After
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45. Stream Restoration
Poplar Springs - Before & After
Drainage Area Phosphorous Nitrogen Removal Sediment Removal
(acres) Removal (lbs/yr) (tons/yr)
(lbs/yr)
230.4 7.5 141 1.25 45

46. Stream Restoration
Government Center - Before & After
Drainage Area Phosphorous Removal Nitrogen Removal Sediment Removal
(acres) (lbs/yr) (lbs/yr) (tons/yr)
150 10.7 202 1.6
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47. Next Steps…
Feasibility study – winter 2013
Stakeholder meeting (if necessary)
Development of Conceptual Designs
Survey
Public Meeting
Preliminary Design – spring 2013
Develop the conceptual design into a plan set
Final Design – spring 2013
Public Meeting
Preliminary design is developed into a construction ready plan set.
Construction – TBD: fall/winter
Public bid process
Construction Notification
Estimated Construction: Time 1 to 1.5 months each project
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48. Post Construction Activity
Plantings
– Within 30 days of construction completion
Maintenance
– Annual inspection
– Monitoring to ensure proper function and identify
need for future maintenance
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49. Resources
Stormwater Planning Division Website
http://www.fairfaxcounty.gov/dpwes/stormwater/
Fairfax County Watershed Planning
http://www.fairfaxcounty.gov/nvswcd/newsletter/planning.htm
Difficult Run Watershed Plan
http://www.fairfaxcounty.gov/dpwes/watersheds/difficultrun_docs.htm
EPA Water Quality Laws & Regulations
http://www.epa.gov/water/laws.html
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50. Fairfax County Vision Elements
•
To protect and enrich the quality of life for the people, neighborhoods and diverse communities of Fairfax County
by:
• Maintaining Safe and Caring Communities
The needs of a diverse and growing community are met through innovative public and private services, community
partnerships and volunteer opportunities. As a result, residents feel safe and secure, capable of accessing the range of
services and opportunities they need, and are willing and able to give back to their community.
• Building Livable Spaces
Together, we encourage distinctive "built environments" that create a sense of place, reflect the character, history and
natural environment of the community, and take a variety of forms -- from identifiable neighborhoods, to main streets, to town
centers. As a result, people throughout the community feel they have unique and desirable places to live, work, shop, play
and connect with others.
• Connecting People and Places
Transportation, technology and information effectively and efficiently connect people and ideas. As a result, people feel a
part of their community and have the ability to access places and resources in a timely, safe and convenient manner.
• Maintaining Healthy Economies
Investments in the workforce, jobs, and community infrastructure and institutions support a diverse and thriving economy. As
a result, individuals are able to meet their needs and have the opportunity to grow and develop their talent and income
according to their potential.
• Practicing Environmental Stewardship
Local government, industry and residents seek ways to use all resources wisely and to protect and enhance the County's
natural environment and open space. As a result, residents feel good about their quality of life and embrace environmental
stewardship as a personal and shared responsibility.
• Creating a Culture of Engagement
Individuals enhance community life by participating in and supporting civic groups, discussion groups, public-private
partnerships and other activities that seek to understand and address community needs and opportunities. As a result,
residents feel that they can make a difference and work in partnership with others to understand and address pressing public
issues.
• Exercising Corporate Stewardship
Fairfax County government is accessible, responsible and accountable. As a result, actions are responsive, providing
superior customer service and reflecting sound management of County resources and assets.
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51. Questions?
Thank You!
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52. Contact Information
Holly Moran, P.E. – Project Engineer
703-324-5613
Holly.Moran@fairfaxcounty.gov
Justin Pistore – Project Manager
703-324-5685
Justin.Pistore@fairfaxcounty.gov
Fairfax County Stormwater Planning Division
703-324-5500 TTY 711
12000 Government Center Parkway
Suite 449
Fairfax, Virginia 22035
www.fairfaxcounty.gov/dpwes/stormwater
To request this information in an alternate format call 703-324-5500,
TTY 711 52