SLIDE 1 Arlington County Watershed Retrofits
Greg Hoffmann & Cecilia Lane Center for Watershed Protection
February 1, 2011 Arlington County, Virginia
SLIDE 2 What Are Stormwater Retrofits?
retrofits are
stormwater management practices in locations where stormwater controls did not previously exist or were ineffective
Rolling Stone Retrofit Montgomery Co., MD
SLIDE 3
SLIDE 4
SLIDE 5
Bioretention Cross Section
SLIDE 6
Bioretention in Action
SLIDE 7
Retrofitting Philosophy
Retrofitting urban watersheds is involves the Art of Opportunity
SLIDE 8
Retrofitting Philosophy
Retrofitting urban watersheds is not about drastic changes to the surface and subsurface landscape.
SLIDE 9 What Did We Do?
– Rapidly search for and identify potential retrofit sites across the subwatershed – Save time in the field
250 potential locations identified:
Donaldson Run: 52 Four Mile Run: 130 Gulf Branch: 68
Desktop Analysis
SLIDE 10
Retrofit Reconnaissance I nventory (RRI )
SLIDE 11
DONALDSON RUN RETROFITS
Site DR-110A: The Water Tower
SLIDE 12
DONALDSON RUN RETROFITS
Site DR-110A: The Water Tower
Bioretention Cell
SLIDE 13
DONALDSON RUN RETROFITS
Site DR-103: County Compost Facility
SLIDE 14
DONALDSON RUN RETROFITS
Site DR-103: County Compost Facility
Bioretention Cell
SLIDE 15
FOUR MILE RUN RETROFITS
Site CR-102N: Bishop O’Connell High School
SLIDE 16
FOUR MILE RUN RETROFITS
Site CR-102N: Bishop O’Connell High School
Bioretention Cell
SLIDE 17
FOUR MILE RUN RETROFITS
Site CR-121: North Trinidad Street
SLIDE 18
FOUR MILE RUN RETROFITS
Site CR-121: North Trinidad Street
Street Bioretention
SLIDE 19
GULF BRANCH RETROFITS
Site GB-114B: Gulf Branch Nature Center
SLIDE 20
GULF BRANCH RETROFITS
Site GB-114B: Gulf Branch Nature Center
Permeable Pavement
SLIDE 21
GULF BRANCH RETROFITS
Site GB-201: Glebe Park and Ethan Allen Park
SLIDE 22
GULF BRANCH RETROFITS
Site GB-201: Glebe Park and Ethan Allen Park
Dry Swale
SLIDE 23
SLIDE 24 How did we do?
Donaldson Run
- 24 viable sites
- 33.64 acres treated
- 13.57 acres of impervious cover treated
- 5% of the watershed treated
- 9% of impervious area treated
- 7.23 lbs of Phosphorus removal per year
- 58.29 lbs of Nitrogen removal per year.
SLIDE 25 How did we do?
Four Mile Run
- 82 viable sites
- 80.09 acres treated
- 39.97 acres of impervious cover treated
- 9.38% of the watershed treated
- 11.2% of impervious area treat
- 29.65 lbs of Phosphorus removal per year
- 246.70 lbs of Nitrogen removal per year.
SLIDE 26 How did we do?
Gulf Branch
- 53 viable sites
- 76.20 acres treated
- 29.69 acres of impervious cover treated
- 14.38% of the watershed treated
- 19.32% of impervious area treated
- 28.40 lbs of Phosphorus removal per year
- 232.47 lbs of Nitrogen removal per year.
