LEED 2012 Rainwater Management

Transcription

1 LEED 2012 Rainwater Management Michele Adams, P.E. LEED AP, Principal, Meliora Design Steve Benz, P.E. LEED AP OLIN, Partner, Dir. Green Infrastructure Members of U.S. Green Building Council SS TAG and SWM Team

2 What is the LEED System? Scores are tallied for different aspects of efficiency and design in appropriate categories. For instance, LEED assesses in detail: LEADERSHIP in ENERGY and ENVIRONMENTAL DESIGN A leading-edge system for certifying DESIGN, CONSTRUCTION, & OPERATIONS of the greenest buildings in the world 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

3 Levels of LEED Ratings Green Buildings worldwide are certified with a voluntary, consensus-based rating system. USGBC has four levels of LEED. Test

4 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

5 Sustainable Sites Credits (14 points) Prereq Construction Pollution Prevention 1 Site Selection 2 Development Density & Community Connectivity 3 Brownfield Alternative Transportation Habitat and Open Space Stormwater Heat Island 8 Light Pollution Water Efficiency Credits (10 points) Prereq Water Use Reduction 1 Water Efficient Landscaping 2 Innovative Wastewater 3 Water Use Reduction (30%- 40%)

6 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

7 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

8 LEED Sustainable Sites Continuous Improvement Priorities Three Raise the bar of existing SS credits IMPACT REGENERATIVE SUSTAINABLE UNSUSTAINABLE Green buildings Conventional buildings PRESENT TIME FUTURE

9 LEED for 2012 What is a truly Sustainable Project? Less Bad? Environmentally Neutral no harm? Regenerative can a project heal the environment? Stormwater is a byproduct, but Rainwater is a resource.

10 EPA s Direction Section 438 of the Energy Independence and Security Act (Dec 2009) Design, construct, and maintain stormwater management practices that.. practices that (Option 1) prevent offsite discharge of the precipitation from all rainfall events less than or equal to the 95 th percentile rainfall event. Retain the 95 th Percentile Rainfall Event OR OR (Option 2) preserve the predevelopment runoff conditions following construction. Site-Specific Hydrologic Analysis 10

11 Two important observations: Frequency: Most of the time, it rains 1 inch or less Annual Percentage of Volume from Storms Volume: In SE PA, 96% of the annual rainfall volume from storms 3 inches or less

12 95 th Percentile for Select U.S. Cities Philadelphia 95 th Percentile: 1.6 (2-year net increase woods to impervious 2.05 C soils)

13 Rainfall Frequency Spectrum channel erosion control overbank control flood control Source: Iowa Stormwater Management Manual Ecological Impact Zone groundwater recharge pollutant load reduction control of channel erosion producing events

14 Rainwater Partitioning Transpiration (productive component in biomass creation) Source: Stockholm International Water Institute Green-water Evapotranspiration Precipitation Blue-water (groundwater, rivers, aquifers, lakes, wetlands, and impoundments) (non-productive) Soil Abstraction (moisture in the unsaturated zone) Ponding (surface storage)

15 How Can We Quantify Performance? Manage volume for 95 th percentile event Small Storm Hydrology and LID Safely convey large events Rainfall record and continuous simulation

16 Small Storm Hydrology Design by Land Use and Rainfall Amount Volume of Runoff = P x R v x Area 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

17 Model My Watershed Stroud Water Research Center A Educational Water Balance Application using Small Storms Hydrology Modeling Dr. Susan Gill, Stroud Water Research Center T. Perlman, R. Cheetham, Azavea Michele Adams, PE, LEED AP, Meliora Design Steve Benz, PE, LEED AP (BD+C)

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20 Intent LEED 2012 Rainwater Credit 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) 95 th Percentile 2 points 95 th Percentile & maintain Pre-Columbian Levels OR 98 th Percentile 3 points

21 LEED 2012 Update: LEED 2012 Rainwater Management Model My Watershed (Stroud Water Research Center): Contacts: Dr. Susan Gill, Director of Education, Michele Adams, P.E. LEED AP Meliora Design Steve Benz, P.E. LEED AP OLIN