Arlington County Watershed Retrofits Greg Hoffmann & Cecilia - PowerPoint PPT Presentation

Arlington County Watershed Retrofits Greg Hoffmann & Cecilia Lane Center for Watershed Protection February 1, 2011 Arlington County, Virginia

What Are Stormwater Retrofits? • Stormwater retrofits are stormwater management practices in locations where stormwater controls did not previously exist or were ineffective Rolling Stone Retrofit Montgomery Co., MD

Bioretention Cross Section

Bioretention in Action

Retrofitting Philosophy Retrofitting urban watersheds is involves the Art of Opportunity

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 • Result 250 potential locations identified: Donaldson Run: 52 Four Mile Run: 130 Gulf Branch: 68

Retrofit Reconnaissance I nventory (RRI )

DONALDSON RUN RETROFITS Site DR-110A: The Water Tower

DONALDSON RUN RETROFITS Site DR-110A: The Water Tower Bioretention Cell

DONALDSON RUN RETROFITS Site DR-103: County Compost Facility

DONALDSON RUN RETROFITS Site DR-103: County Compost Facility Bioretention Cell

FOUR MILE RUN RETROFITS Site CR-102N: Bishop O’Connell High School

FOUR MILE RUN RETROFITS Site CR-102N: Bishop O’Connell High School Bioretention Cell

FOUR MILE RUN RETROFITS Site CR-121: North Trinidad Street

FOUR MILE RUN RETROFITS Site CR-121: North Trinidad Street Street Bioretention

GULF BRANCH RETROFITS Site GB-114B: Gulf Branch Nature Center

GULF BRANCH RETROFITS Site GB-114B: Gulf Branch Nature Center Permeable Pavement

GULF BRANCH RETROFITS Site GB-201: Glebe Park and Ethan Allen Park

GULF BRANCH RETROFITS Site GB-201: Glebe Park and Ethan Allen Park Dry Swale

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.

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.

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.