Arlington County Watershed Retrofits Greg Hoffmann & Cecilia Lane Center for Watershed Protection September 19 Septembe 19, 2011 Arlington County, Virginia
What Are Stormwater Retrofits? • Stormwater retrofits are stormwater management practices in locations where h stormwater t t controls did not previously exist or were ineffective Rolling Stone Retrofit Montgomery Co., MD
Bioretention in Action
Retrofitting Philosophy Retrofitting urban watersheds is involves the A t off O Art Opportunity t it
Retrofitting Philosophy Retrofitting urban watersheds is not about drastic changes to the surface and subsurface landscape.
What Did We Do? Desktop Analysis • Purpose – Rapidly search for and identify potential retrofit sites across the subwatershed – Save time in the field
DOCTOR’S BRANCH RETROFITS Site DB-130: Arlington Hall Park
DOCTOR’S BRANCH RETROFITS Site DB-130: Arlington Hall Park
Bioretention Cell
LUBBER RUN RETROFITS Site LR-114: Lubber Run Community Center
LUBBER RUN RETROFITS Site LR-114: Lubber Run Community Center
Bioretention Cell
H How did we d do? ?
Results Doctor’s Branch • 76 viable sites • 73.48 acres treated • 36.15 acres of impervious cover treated • 8% of the watershed treated • 12% of impervious area treated • 35.10 35 10 lbs of Phosphorus removal per year • 288.73 lbs of Nitrogen removal per year.
Results Lubber Run • 141 viable sites • 129.67 acres treated • 64.51 acres of impervious cover treated • 13% of the watershed treated • 17% of impervious area treated • 49.36 49 36 lbs of Phosphorus removal per year • 396.98 lbs of Nitrogen removal per year.
Results Spout Run • 70 viable sites • 53.46 acres treated • 28.03 acres of impervious cover treated • 5% of the watershed treated • 7% of impervious area treated • 22.18 22 18 lbs of Phosphorus removal per year • 180.92 lbs of Nitrogen removal per year.
Results Windy Run • 23 viable sites • 30.28 acres treated • 12.07 acres of impervious cover treated • 10% of the watershed treated • 18% of impervious area treated • 8.45 8 45 lbs of Phosphorus removal per year • 70.35 lbs of Nitrogen removal per year.
Next Steps
Arlington County Constructed Retrofits
McKinley School
Marymount University
Patrick Henry Drive
DOCTOR’S BRANCH RETROFITS Site DB-101: North Quincy Street/Mosaic Park
DOCTOR’S BRANCH RETROFITS Site DB-101: North Quincy Street/Mosaic Park