leed ® 2012 rainwater management
TRANSCRIPT
LEED ® 2012 Rainwater Management
Michele Adams, P.E. LEED® AP, Principal, Meliora DesignSteve Benz, P.E. LEED® AP OLIN, Partner, Dir. Green Infrastructure
Members of U.S. Green Building Council SS TAG and “SWM” Team
Test
What is the LEED System?
LEADERSHIP inENERGY andENVIRONMENTALDESIGN
A leading-edge system for certifyingDESIGN, CONSTRUCTION, & OPERATIONSof the greenest buildings in the world
Scores are tallied for different aspects of efficiency and design in appropriate categories.
For instance, LEED assesses in detail:
1. Sustainable Sites (SS)2. Water Efficiency (WE)3. Energy & Atmosphere (EA)4. Materials & Resources (MR) 5. Indoor
Environmental Quality (IEQ)6. Innovation &
Design Process
Test
Levels of LEED Ratings
Green Buildings worldwide are certified with a voluntary,consensus-based rating system.USGBC has four levels of LEED.
LEED is an evolving process….® is an Evolving System
• LEED v1.0 launched 1998• LEED for New Construction (NC) v2.0, v2.1, v2.2, and v3.0 (2009)• LEED Standards Developed for:
– Core and Shell – Schools– Homes– Neighborhood Development– Commercial Interiors– Existing Buildings: Operation and Maintenance (EBOM)
• Next: LEED 2012
Sustainable Sites Credits (14 points)
Prereq Water Use Reduction1 Water Efficient Landscaping 2 Innovative Wastewater 3 Water Use Reduction (30%- 40%)
Water Efficiency Credits (10 points)
Prereq Construction Pollution Prevention1 Site Selection2 Development Density & Community Connectivity3 Brownfield
4.1 – 4.2 Alternative Transportation5.1 – 5.2 Habitat and Open Space6.1 – 6.2 Stormwater7.1 – 7.2 Heat Island
8 Light Pollution
Current LEED Stormwater Credits 6.1 and 6.2
• Intent– Limit disturbance of natural hydrology – Reduce pollution, eliminate contaminants– Reduce runoff volume
• Peak discharge rate and quantity cannot exceed predevelopment (1- and 2-year 24-hour design storms)
• Remove 80% total suspended solids (TSS)
Few projects achieve quantity control
LEED Shortcomings and the Sustainable Sites Initiative (SITES)
• What if there is no building?• Not comprehensive• Can still do “unsustainable” things
SITES: First national system for sustainable landscapes– ASLA, Lady Bird Johnson, U.S.
Botanic Garden– “Ecosystem Services” concept
LEED Sustainable SitesContinuous Improvement Priorities
Three – Raise the bar of existing SS credits
TIME
IMPA
CT
SUSTAINABLE
PRESENT FUTURE
REGENERATIVE
UNSUSTAINABLE
Green buildings
Conventional buildings
LEED for 2012What is a truly Sustainable Project?
• “Less” Bad?• Environmentally Neutral – no harm?• Regenerative – can a project heal the environment?
Stormwater is a byproduct, butRainwater is a resource.
10
Section 438 of the Energy Independence and Security Act (Dec 2009)
… (Option 1) prevent offsite discharge of the precipitation from all rainfall events less than or equal to the 95th percentile rainfall event.
Design, construct, and maintain stormwater management practices that….. practices that…
… (Option 2) preserve the pre-development runoff conditions following construction.
Retain the 95th
Percentile Rainfall Event
Site-Specific Hydrologic Analysis
OR
EPA’s Direction
OR
Two important observations:
Volume: In SE PA, 96% of the annual rainfall volume from storms 3
inches or less
Frequency: Most of the time, it rains 1 inch or less
Annual Percentage of Volume from Storms
95th Percentile for Select U.S. Cities
Philadelphia 95th Percentile: 1.6”(2-year net increase woods to impervious 2.05” C soils)
Source: Iowa Stormwater Management Manual
Ecological Impact Zone
Rainfall Frequency Spectrum
groundwater rechargepollutant load reduction
control of channel erosion producing events
channel erosion controloverbank control
flood control
Rainwater Partitioning
Precipitation
Green-water
Blue-water (groundwater, rivers, aquifers, lakes, wetlands, and
impoundments)
Transpiration
(productive component in biomass creation)
Evapotranspiration
(non-productive)
Soil Abstraction (moisture in the unsaturated
zone)
Ponding(surface storage)
Source: Stockholm International Water Institute
How Can We Quantify Performance?
• Manage volume for 95th percentile event– Small Storm Hydrology and LID
• Safely convey large events– Rainfall record and continuous simulation
Small Storm Hydrology
Google “Bob Pitt”Click on “Publications”
“Small Storm Hydrology and Why it is Important for the Design of Stormwater Control Practices” Robert Pitt, P.E., Ph.D., DEE Department of Civil and Environmental Engineering The University of Alabama
Design by Land Use and Rainfall Amount
Volume of Runoff = P x Rv x Area
Model My WatershedStroud Water Research Center
A Educational Water Balance Application
usingSmall Storms Hydrology Modeling
Dr. Susan Gill, Stroud Water Research CenterT. Perlman, R. Cheetham, AzaveaMichele Adams, PE, LEED AP, Meliora DesignSteve Benz, PE, LEED AP (BD+C)
LEED 2012 Rainwater Credit
• Intent– Restore and maintain natural hydrology and water
balance– Based on historic Ecosystems of the region– Reduce runoff volume
• Manage on-site runoff using Low Impact Development (LID)– 95th Percentile 2 points– 95th Percentile & maintain Pre-Columbian Levels OR– 98th Percentile 3 points
LEED ® 2012 Rainwater Management
LEED 2012 Update:
www.usgbc.org
Model My Watershed (Stroud Water Research Center):
www.Wiwkiwatershed.org
Contacts:
Dr. Susan Gill, Director of Education, [email protected] Adams, P.E. LEED® AP Meliora Design [email protected] Benz, P.E. LEED® AP OLIN [email protected]