Innovative Stormwater Management in Urban Environments Cahill Associates Environmental Consultants www.thcahill.com Urban SW Issues No Stormwater Management Combined Sewers Buried Streams and Dead Streams Undersized Conveyance and Surcharging High Non-point source pollutant loads Lack of Vegetation 1
Urban SW Challenges Little Open Space Buried Utilities (steam, gas, sewer ) Disturbed Soils Site Contamination! Staging and Construction Real Estate at a Premium! Project: Penn-Alexander School Location: 43 rd and Locust, West Philadelphia, Mill Creek Watershed Partners: University of Pennsylvania Philadelphia Water Department School District of Philadelphia Morris Arboretum PaDEP Growing Greener 2
Penn-Alexander School PaDEP Growing Greener & Philadelphia Water Department Porous Pavement Playground Infiltration Bed Beneath Athletic Field Rain Garden and Native Vegetation Environmental Education Site location map 3
Mill Creek Watershed Burying of Mill Creek Late 1800 s 4
Mill Creek buried 60ft down! Goals Environmental Education and Outreach Public School Children Inner-City Neighborhood Community Open Green Space in Philadelphia Environmental Diversity Neighborhood Revitalization Native Flora and Fauna Sustainable Development 5
Goals (con t) Nonpoint Source Pollution Reduction Mill Creek and Schuylkill River Incorporating BMPS Philadelphia s Stormwater Management Plan Schuylkill River Conservation Plan Reducing Flows and Time of Concentration thereby reducing frequency and duration of CSOs 6
Porous pavement playground Recharge garden Playfield infiltration bed Penn-Alexander School Stormwater Management Plan Storage Capacity of SW System Playfield Infiltration Bed: - 18 deep, 2500 cu.ft. dead storage, 3500 cu.ft. infiltration volume, total volume mitigation = 6000 cu.ft. (>25 yr-storm) Porous Pavement/Playground Infiltration Bed: - 18 deep, 1300 cu.ft. dead storage, 2080 cu.ft. infiltration volume, total volume mitigation = 3380 cu.ft. (>2 yr-storm) 7
Porous Pavement Playground under construction Porous Pavement Playground 8
Existing Parking Lot site of new playfield Playfield W/ Subsurface Infiltration Bed 9
A. Precipitation is carried from roof by roof drains to storage beds. B. Stormwater runoff from impervious and lawn areas is carried to storage beds. C. Precipitation that falls on porous paving enters storage beds directly D. Stone beds with 40% void space store water. Continuously perforated pipes distribute stormwater from impervious surfaces evenly throughout the beds. E. Stormwater exfiltrates from storage beds into soil, recharging groundwater. 10
Rain Gardens & Vegetated Swales Modified Soils Depression Storage Native Plantings Reduced Fertilization Rain Garden 11
Project: Washington National Cathedral, D.C. 12
Washington National Cathedral, D.C. Cathedral and Parking on top of hill Surrounded by Olmsted s Woods Point Discharges eroding hillside Lack of Recharge: Diminished Soil Moisture and Dying Trees Invasive Vegetation Cathedral Concept Plan 13
Existing Outfall from Pilgrim Road Disconnected Outfall from Pilgrim Road W/ Stabilizing Check Logs 14
ACF Environmental Inc. Invisible Structures BMP Solutions for Storm Water Management Stacked Into Cells cells of 25 unit each 2.5 meters tall (8.2 feet) Cells Assembled At Manufacturing Facility To custom height (from 0.1 m to 2.5 m) 15
Rainstore Bed under construction Rainstore Bed under construction 16
Completed Rainstore Bed Area Pilgrim Road infiltration trench under construction 17
Pilgrim Road infiltration trench Washington National Cathedral, D.C. Connect Roof Leaders to Infiltration Bed at top of Woods Infiltration Trenches Reduce/Eliminate Point Discharges eroding hillside Restore Channels, Install Check Dams Planting program Large Storm Overflow to City Storm Sewer 18
Infiltration Trenches 19
Penn State Berks Campus Reduce Site Disturbance Porous Pavement Infiltration beneath walkways Reduced Impervious Walkways - Grasspave Infiltration with Shallow Contour Trench Eliminated Existing Small Detention Basin Limestone geology 20
Infiltration Beneath Walkways 21
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Shallow Contour Trenches 24
NO!! Villanova University Porous Concrete Plaza Education and Research for Students Remove cars from student area 25
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Swarthmore College Summer 2002 Swarthmore College Summer 2003 27
UNC Chapel Hill UNC Chapel Hill 28
Town of Chapel Hill Stormwater Requirements No Increase in Volume for 2-Year Storm Reduce Total Suspended Solids by 85% Improve Water Quality Manage Peak Rates Ramshead Site Plan 29
DINING HALL STUDENT RECREATION VEGETATED AREAS WALL CISTERN 6" TOP LAYER 16-28" MIDDLE LAYER 8" DRAINAGE LAYER BRICK PAVER AND SAND BASE (4.33") 9.67" DRAINAGE LAYER 16" HIGH CAPACITY STORAGE MEDIA (E.G. RAINSTORE) 30
Ehringhaus Field Section Carmichael Field Site Plan 31
Major Elements of Stormwater Management at the Arts Commons Parking Garage or Landscaped Commons Tree trenches with infiltration Storm sewers that infiltrate Surface inlets that capture detritus/debris Fertilizer minimization program Surface maintenance program 32
Infiltration Trench Under Planted Area 33
Underground Cistern for Irrigation 34
Industrial Ford Motor Company Slow Discharge to Wetlands and Vegetated Systems Green Roofs More Vegetation! Ford Rouge Center Dearborn, Michigan Ford Rouge Center 1952 Artist Richard Rochon's rendering of an aerial view of the Ford Rouge Center that includes the new Ford assembly plant. 35
Strategy for Water Quality DIRECT RAINFALL WATER QUALITY SWALE OPEN EDGE DRAIN RUNOFF IF IMPERVIOUS H-20 RATED CAST IRON GRATE SLAG RETENTION BED 2" x 6" RECTANGULAR EMERGENCY OVERFLOW (3) 1" Ø ORIFICE(S) 40" - 48" TO WATER TABLE ROOF LEADERS SHOULD BE EXTENDED INTO THE RETENTION BED WHERE POSSIBLE 36
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Vegetated Infiltration Swale Ford Rouge 2003 38
CUSANO ENVIRONMENTAL EDUCATION CENTER Philadelphia, Pennsylvania AIA Top Ten Environmental Projects 2003 39
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Construction of New Porous Pavement Lot 41
Vegetated Roof Technologies Annual Hydrologic Cycle For an Average Year 42
Fencing Academy of Philadephia Roofmeadow TM After Before 43
Development of Green Roofs Original concept in Switzerland 1970 s German cities rebuilt after WWII overloaded combined sewer systems Cities mandated green roof systems All new buildings with roofs up to 21 deg. Cheaper than rebuilding sewers Willie-Betz Transport Facility Over 12-acres of Vegetated Roofs Cistern for Firefighting Infiltration Trenches and Basins Bioswales Collection System for Polluted Parking Lot Runoff Goal of Zero-Discharge of Stormwater 44
Simple Vegetated Roof 45
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Parking Garage in Munich 47
CURVED ROOF DESIGN warehouse Munich Convention Center 48
Rail System in Munich 49
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New Housing Development in Stuttgart Vegetative Cover on Houses and Carports Overflow from Green Roofs flows into Gardens then into Infiltration Basins and Wetlands Grass Paved Parking Spaces 51
Only a Minute Flow from the Houses Mienes Hospital in Munich 20-years old 52
Parking Garage 53
German Doghouse Stuttgart s Green Space 54
Three Levels of Green Roofs 1 Above Parking Garage 2 2 nd Floor 3 Top of Building 3 2 1 55
Amsterdam International Airport OLD GREEN ROOF OSLO, NORWAY Approx. 350 years old Primarily for insulation Wooden box frame 56
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