Government Center Pond Retrofit - May 2013 Detention Basin Retrofit Project Braddock District

1. FAIRFAX CO LANDBAY C, PD-4
Detention Basin Retrofit Project
Braddock District
Project No. SD-000031-066

2. Description and Overview:
This stormwater management facility (Facility ID 0595DP) is located at 12000 Government Center Parkway. The facility
was originally built to help control approximately 17 acres of drainage area, with 9 acres of impervious area. The basin
drains to the Difficult Run Watershed and then to the Potomac River. This retrofit project was initiated for the purpose of
improving water quality, habitat, and aesthetic quality. The designed wetland element of this pond’s retrofit will help
reduce the velocity of the runoff before it discharges to the natural channel. The completed facility will provide for 100%
of the 1-inch water quality volume treatment within the existing facility BMP elevations.
Project Scope of Work:
• The existing basin was re-graded to remove sediments and to form an extended flow path design.
• Three shallow micro-pools were created to retain runoff.
• An underlying gravel gallery infiltration system was constructed to intercept and cool the first flush of runoff; in
addition to provide ease of drainage when needed during routine maintenance.
• Imbricated stone was utilized to stabilize at the inlets and outlets and for maintenance accessibility.
• Placement of compost blanket within the newly graded basin to improve soil infiltration and provide rich growth
medium for the newly established native plant communities.
• Incorporation of various trees, shrubs, and native grass/wildflower seed mixes to help with the uptake and treatment
of pollutant entering the basin.
DPWES Project Team:
• Project Manager – Jasdeep Saini
• Construction Manager – Yudhie Brownson
• Project Inspectors - Jack Schambach & Keith Ferrell
• Survey Analyst - Gregory Harper & Gregg Housley
Project Details

3. This Stormwater Management Facility is adjacent to the Fairfax County Government Center
located at 12000 Government Center Parkway.
Site Limits
Government Center Parkway - Tax Map No. 56-1 & 56-2
Stormwater Management Facility ID 0065DP

4. Pre-existing Condition

5. Post Construction
Various plantings and trees scheduled throughout
the facility at the start of growing season

6. Post Construction: Riser Structure

7. Shallow Micro-
Pools
Post Construction: Concrete channel was removed; micro-
pools and an extended flow path design were incorporated

8. Construction of Gravel Gallery Infiltration System

9. Post Construction: Imbricated Rocks Armoring
Existing Inlets for Stabilization and Scour Protection
Inlets- Conveying Parking Lot Runoffs

10. For additional Information, please call
Irene Haske, Public Information Officer
703-324-5821, TTY 711
SWPDmail@fairfaxcounty.gov
www.fairfaxcounty.gov/dpwes