Williamsburg Boulevard Williamsburg Boulevard Green Street Project - PowerPoint PPT Presentation

Williamsburg Boulevard Williamsburg Boulevard Green Street Project Green Street Project June 13, 2012 June 13, 2012 , Williamsburg Middle School Williamsburg Middle School

Relevant Outreach Relevant Outreach Relevant Outreach Relevant Outreach  November 12, 2008: November 12, 2008: Introduction to Little Introduction to Little Pimmit Pimmit Run Watershed Retrofits Workshop, Run Watershed Retrofits Workshop, Yorktown High School Yorktown High School  June 4, 2009: June 4, 2009: Little Little Pimmit Pimmit Run Watershed Run Watershed Retrofit Study Results Workshop, Yorktown High Retrofit Study Results Workshop, Yorktown High School School School School  April 27, 2011: April 27, 2011: Williamsburg Median Green Williamsburg Median Green Street Project Williamsburg Middle School Street Project Williamsburg Middle School Street Project, Williamsburg Middle School Street Project, Williamsburg Middle School  June 13, 2012: June 13, 2012: Williamsburg Median Green Williamsburg Median Green Street Project Update Williamsburg Middle Street Project Update Williamsburg Middle Street Project Update, Williamsburg Middle Street Project Update, Williamsburg Middle School School

What is a Green Street? What is a Green Street? A green street incorporates landscape features A green street incorporates landscape features that reduce the impact of polluted runoff on our that reduce the impact of polluted runoff on our that reduce the impact of polluted runoff on our that reduce the impact of polluted runoff on our streams and the Chesapeake Bay. streams and the Chesapeake Bay.

Rain Gardens Rain Gardens A landscaped A landscaped A landscaped A landscaped depression depression with the with the ability to capture, ability to capture, temporarily retain, temporarily retain, and filter surface and filter surface runoff runoff runoff runoff A rain garden is a storm A rain garden is a storm water treatment facility. water treatment facility. Fairlington Community Center Also known as: Also known as: Al Al k k Bioretention Bioretention, , Biofilter Biofilter, , Bioretention Bioretention Filter, Filter, Bioretention Bioretention Basin Basin

Green Street Green Street Rain Garden Rain Garden Runoff Plants Plants Overflow str Water Surface Ground surface 6”- 12” ponding area 3” mulch 3 mulch 2’ - 3’ soil underdrain 3”- 6” pea gravel 1-2’ coarse gravel

Most of Arlington County developed Most of Arlington County developed without stormwater without without stormwater without stormwater management stormwater management management management Storm drain Storm drain to local stream To the To the Potomac River Water in storm drains does On to the not go to a treatment plant… Chesapeake Bay

Effect of Urbanization Effect of Urbanization Impervious surface f Runoff speed p and volume Water Quality G Groundwater d t supply Stream health Stream Corridor Restoration, FISRWG, 1998

Chesapeake Bay Required Pollution Reductions - 2025 Nitrogen 7% Phosphorus 13% S di Sediment t 18% 18% 3,000 streetscape retrofit projects projects

Impervious Surfaces in Arlington Impervious Surfaces in Arlington Roads Buildings Parking Lots Sidewalks Driveways Other 7% 5% 8% 34% 34% 16% 30% Impervious cover Impervious cover in Arlington = 41% or 6867 acres

Stormwater Stormwater Master Plan Update Master Plan Update p  Storm Sewer Capacity Storm Sewer Capacity Analysis Analysis  County County- -wide wide stream stream inventory inventory  Watershed retrofit plans Watershed retrofit plans to identify locations where to identify locations where stormwater stormwater treatment facilities can be added to help treatment facilities can be added to help slow down and filter slow down and filter stormwater stormwater runoff. runoff. Each plan Each plan contains an inventory of projects contains an inventory of projects contains an inventory of projects. contains an inventory of projects.  Rain gardens Rain gardens  Removing pavement/impervious surface Removing pavement/impervious surface g Little Little Pimmit Pimmit Run Watershed Retrofit Plan Run Watershed Retrofit Plan http://www.arlingtonva.us/departments/Environment htt htt http://www.arlingtonva.us/departments/Environment // // li li t t /d /d t t t /E t /E i i t t alServices/Sustainability/page75627.aspx alServices/Sustainability/page75627.aspx

Retrofit Ranking Criteria Retrofit Ranking Criteria

Project Components Project Components Project Components Project Components  Two rain gardens (1 in each median  Two rain gardens (1 in each median Two rain gardens (1 in each median Two rain gardens (1 in each median rd and 34 th Rds section) between 33 rd and 34 th section) between 33 Rds N N  New median curb improved intersections  New median curb, improved intersections New median curb improved intersections New median curb, improved intersections and repaving and repaving  New canopy trees between Old Dominion N New canopy trees between Old Dominion N t t b t b t Old D Old D i i i i rd Rd N and between 35 th St and Dr. and 33 rd Rd N and between 35 th Dr. and 33 St and th Rd N th Rd N. 34 th 34 th 34 34 Rd N Rd N.

New Project Elements New Project Elements New Project Elements New Project Elements th Rd to 34 th St rain (34 th Rd to 34 th  Addition of  Addition of Addition of forebays Addition of forebays forebays (34 forebays (34 (34 Rd to 34 Rd to 34 St rain St rain St rain garden) garden)  Planting plan for rain gardens  Planting plan for rain gardens Planting plan for rain gardens Planting plan for rain gardens  Coordination with 36” water main project Coordination with 36” water main project  Coordination with Old Dominion Drive Coordination with Old Dominion Drive Pedestrian Improvement Project Pedestrian Improvement Project

Williamsburg Green Street Williamsburg Green Street g a) 4 sections b) 3 b) 3 sections ti

Williamsburg Green Street Williamsburg Green Street 36” Water Main a) 4 sections b) 3 sections b) 3 sections

Rain Garden Drainage Areas Rain Garden Drainage Areas Rain Garden Drainage Areas Rain Garden Drainage Areas  Total drainage area: 1.8 acres Total drainage area: 1.8 acres g  Impervious area treated: 1.1 acres Impervious area treated: 1.1 acres ft 3 (33,345 ft 3 (33 345  Water treated:  Water treated: Water treated: 4458 Water treated: 4458 4458 ft 4458 ft 33 345 gallons) 33,345 gallons) gallons) gallons) A A B B

Concrete Curb cut Pipe 5-8” weir River Rock Concrete weir 3-5” River Rock

Forebays Forebays y  Receive Receive stormwater stormwater    Slow runoff Slow runoff  Prevent erosion Prevent erosion  M k  Make rain garden easier Make rain garden easier M k i i d d i i to maintain to maintain  Decrease rain garden Decrease rain garden g depth depth

Williamsburg Williamsburg Bioretention Bioretention Typical Cross Typical Cross- -Section Section 13’ 6” plants 6” curb 3” mulch 3’ soil 1’ 1 – 2 2’ 3” pea gravel Max 2 ¼ ’ 1’ gravel underdrain underdrain

Trees and Plants Trees and Plants Trees and Plants Trees and Plants  14 trees and 2 shrubs will be removed; 2  14 trees and 2 shrubs will be removed; 2 14 trees and 2 shrubs will be removed; 2 14 trees and 2 shrubs will be removed; 2 transplanted transplanted  Includes 3 mature trees (> 10  Includes 3 mature trees (> 10 Includes 3 mature trees (> 10 dbh Includes 3 mature trees (> 10 dbh dbh) dbh) – all ) – all all all exhibiting signs of stress exhibiting signs of stress  7 canopy trees; 7 small trees and  7 canopy trees; 7 small trees and 7 canopy trees; 7 small trees and ±16 7 canopy trees; 7 small trees and ±16 16 16 shrubs will be planted shrubs will be planted  Numerous flowering perennials and N N Numerous flowering perennials and fl fl i i i l i l d d grasses grasses  All plants will be native, salt tolerant All plants will be native, salt tolerant

Rain Garden Planting Plan Rain Garden Planting Plan Rain Garden Planting Plan Rain Garden Planting Plan

Purple Coneflower Allegheny serviceberry Sea Oats Obedient Smooth plant blue aster Winterberry Beardtongue

Maintenance Maintenance Maintenance Maintenance  Initially after any large storms  Initially, after any large storms Initially after any large storms Initially, after any large storms  Thereafter, quarterly Thereafter, quarterly  Remove sediment R R Remove sediment di di t t  Weed, inspect, replant, prune plants Weed, inspect, replant, prune plants  Remove trash Remove trash  Make sure  Make sure Make sure underdrain Make sure underdrain underdrain overflow all pipes underdrain, overflow, all pipes , overflow, all pipes overflow all pipes and catch basins working correctly and catch basins working correctly