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Sustainable Site Development: Land Development as Nature Intended Low Impact Development Specifics and Green Building Standards

Copyright Materials This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. © Weston & Sampson 2009

Michael Clark, PE, LEED AP www.westonandsampson.com [email_address] Low Impact Development Specifics

Learning Objectives At the end of this program, participants will be able to: 24 Green Roofs / 49 Water Conservation - Using Low Impact Development practices and techniques the participant will be able to evaluate site conditions, and collaborate with owners, civil engineers and landscape architects, to successfully design a sustainable site which seeks to replicate the natural surface and ground water hydrology thus protecting water quality and reducing run-off. 22 Environmental Education - Participants will be able to select and identify the appropriate pre-requisites and credits applicable to Low Impact Development practices to successfully complete sustainable site certification from three Green Building/Development Certification Programs.

A more sustainable land development approach Based on an environmentally sensitive site planning process; and A stormwater management strategy to mimic natural hydrology. An Introduction to LOW IMPACT DEVELOPMENT Alternative Approaches to Stormwater Management

Courtesy May, U of W Natural Conditions Hydrology 101

Courtesy May, U of W Developed Conditions Hydrology 101

WHY IS L.I.D. NEEDED? Maintain Natural Watershed characteristics Protect Recharge Areas and Ecological Integrity of Our Receiving Waters Control Water Quantity and Water Quality Restore / improve areas already developed An Introduction to LOW IMPACT DEVELOPMENT Alternative Approaches to Stormwater Management

Better site design: to identify and preserve natural features; to maintain natural hydrology; to help respect abutter’s properties; to retain property values; to augment groundwater supplies; to maintain high water quality. Local Authorities’ Perspective:

The Problem Conventional Development Smart Development Reduce land clearing and grading costs Reduced infrastructure costs Protect regional water quality Reduce stormwater runoff The Solution Impacts on open space

Conventional Development Centralized Pipe and Pond Controls

LID Development Conservation Minimization Soil Management Open Drainage Rain Gardens Rain Barrels Pollution Prevention Disconnected Decentralized Distributed Multi-functional Multiple Systems

Green Connection Lid June 2009

LID Site Design Conservation of natural hydrology, trees, and vegetation Minimized impervious surfaces Dispersal of stormwater runoff Conservation of stream & wetland buffers Ecological landscaping

The standard planning process involves four-steps, after the yield is established. Source: R. Arendt

Identify conservation value areas on the site such as wetlands, significant trees or tracts of forest, steep slopes, habitat, cultural resources or buffer zones. Remove these from the “developable area”. 1. Source: R. Arendt

Place houses in the remaining area in a way that would maximize residents enjoyment of protected areas by providing access to open space and preserving views. 2. Source: R. Arendt

Align roads and trails on the site to provide pedestrian and vehicle access and maximize stormwater management options. 3. Source: R. Arendt

4. Draw lot lines around the homes.

Reduce Stormwater Runoff, Treat Non-Point Source Pollution Site planning techniques (narrower roads, conserved natural areas, preserve natural depressions) Dry wells for rooftop runoff; Grassed (vegetated) swales; Filter buffer strips; Soil Augmentation; Bioretention areas; Permeable pavers; Green roofs; Rain barrels and cisterns; and Stormwater planters. LID Best Management Practices

Conservation Open Drainage Rain Gardens Amended Soils Rain Barrel Lot Level Source Controls LID Site Porous Pavement Create a Hydrologically Functional Lot Narrower Streets

Number of Accidents as a Function of Residential Street Width Source: Swift, et. al., 1998

Better Site Design of Roadways & Driveways Narrower streets Alternative cul-de sacs Shared driveways Source: City of Portland, OR Source: CWP Sarasota, FL

Better Parking Lot Design Green strips provide shade can use for stormwater collection & treatment reduce need for large unsightly detention enhance aesthetics Reduce overall parking create multiple small lots allow shared parking reduce space size Porous Pavement (in outlying overflow areas) Sarasota FL reduce runoff volumes & reduce pollution

Infiltration to replenish groundwater supplies and maintain baseflows to streams & wetlands; Less runoff and sediment to public drainage system = lower maintenance costs; PROBLEM : Downspouts Connected to Driveway = More Runoff, Less Infiltration OBJECTIVES :

SOLUTIONS : Dry Well Infiltration of Roof Runoff Rooftop Runoff to vegetated swale Source: CWP

Grassed Swales (aka “vegetated swales”) Provides better water quality treatment; Reduces infrastructure (drainage) costs; Reduces size and cost of detention basins; Is visible and affords better maintenance; Aesthetics may increase property values

Vegetated Swales Conveyance, Treatment, Infiltration Roadside swales (country drainage) for lower density and small-scale projects; For small parking lots; Mild side slopes and flat longitudinal slopes; Provides area for snow storage & snowmelt treatment

Bioretention (Biofiltration) Treatment, Retention, Infiltration, Landscaping Excavation filled with engineered soil mix Herbaceous perennials, shrubs, trees Ponded water infiltrates within 72 hours Overflow outlet and optional underdrain Source: CWP

Bioretention Treatment, Retention, Infiltration, Landscaping

Ref: Preliminary Sarasota County LID Manual, 2008 Bioretention Plan View

Soil / Flora / Fauna Ecological Structure A Dynamic Living Ecosystem Cycling Nutrients, Chemicals and Organic Energy Sources Plants, Bacteria Protozoa, Fungus Worms, Insects Mammals .

Bioretention Applications Parking lot islands Median strips Office parks Residential lots

Bioretention Area Small parking lots

Bioretention Applications Urban retrofits High-density areas

Grass pavers Paving stones Porous asphalt Pervious concrete Reinforced turf Permeable Paving Runoff Reduction

Permeable Paving Applications Parking stalls Overflow parking Driveways Walkways and plazas

Green Roof Systems Runoff Reduction, Reduced Heating / Cooling Costs Rainwater stored in a lightweight engineered soil medium; Hardy, drought-resistant vegetation; Reduces runoff by 50%. Not recommended in watersheds where baseflows are already diminished.

Rain Barrels and Cisterns Runoff Reduction and Water Conservation Downspouts directed to tanks or barrels; 50 –10,000 gallons; Excess diverted to drywell or rain garden; Landscaping, car washing, other non- potable uses.

Rain Barrels and Cisterns Runoff Reduction and Water Conservation Large-Scale Applications

Stormwater Planters Runoff Reduction, Treatment, Attenuation “ Bioretention in a Box” Vegetative uptake of stormwater pollutants Pretreatment for suspended solids Aesthetically pleasing Reduction of peak discharge rate Source: City of Portland, OR Source: City of Portland, OR

LEED 2009 NC SSc 1 – Site Selection SS Credit 5.1: Site Development—Protect or Restore Habitat SS Credit 5.2: Site Development—Maximize Open Space SSc 6.1 Stormwater Design – Quantity Control SSc 6.2 Stormwater Design – Quality Control SSc 7.1 Heat Island Effect – Non Roof: Option 1 Use an open-grid pavement system (at least 50% pervious). SSc 7.2 Heat Island Effect – Roof

LEED 2009 NC SSc 1 – Site Selection To avoid the development of inappropriate sites and reduce the environmental impact from the location of a building on a site. Do not develop buildings, hardscape, roads or parking areas on portions of sites that meet any of the following criteria: Within 100 feet of wetlands. Within 50 feet of a waterbody.

LEED 2009 NC SS Credit 5.1: Site Development Protect or Restore Habitat Case 1: Greenfields - Limit all site disturbance to the following parameters: 25 feet beyond constructed areas with permeable surfaces (such as pervious paving areas, stormwater detention facilities and playing fields) that require additional staging areas to limit compaction in the constructed area.

LEED 2009 NC SS Credit 5.1: Site Development Protect or Restore Habitat Case 2: Previously Developed Sites or Graded Areas- Restore or protect a minimum of 50% of the site or 20% of the total site. Projects earning SS Credit 2: Development Density and Community Connectivity may include vegetated roof surface in this calculation if the plants are native or adapted, provide habitat, and promote biodiversity.

LEED 2009 NC SS Credit 5.2: Site Development Maximize Open Space Perform a site survey to identify site elements and adopt a master plan for developing the project site. Select a suitable building location and design the building footprint to minimize site disruption.

LEED 2009 NC SSc 6.1 Stormwater Design Quantity Control Design the project site to maintain natural stormwater flows by promoting infiltration. Specify vegetated roofs, pervious paving and other measures to minimize impervious surfaces. Reuse stormwater for non-potable uses such as landscape irrigation, toilet and urinal flushing, and custodial uses.

LEED 2009 NC SSc 6.2 Stormwater Design – Quality Control Implement a stormwater management plan that reduces impervious cover, promotes infiltration and captures and treats the stormwater runoff from 90% of the average annual rainfall1 using acceptable best management practices (BMPs). BMPs used to treat runoff must be capable of removing 80% of the average annual postdevelopment total suspended solids (TSS) load based on existing monitoring reports.

LEED 2009 NC SSc 6.2 Stormwater Design – Quality Control Use treatment train approach. Bioretention: >80% TSS removal Vegetated Filter strip: 25-50’ wide - 10% TSS removal >50’ wide - 40% TSS removal Vegetated swales: 50 to 70% TSS removal Porous Pavement: >80% TSS removal Rain barrels, green roofs and cisterns: roof / pavement surface can be deducted from the impervious area used to calculate the Required Water Quality Volume for sizing other structural treatment BMPs.

LEED 2009 NC SSc 7.1 Heat Island Effect – Non Roof Option 1: Use an open-grid pavement system (at least 50% pervious). Option 2: Place 50% of parking spaces under cover – green roof.

LEED 2009 NC SSc 7.2 Heat Island Effect – Roof Use a vegetated roof that covers at least 50% of the roof surface.

LEED 2009 NC WEc Credit 1: Water Efficient Landscaping Reduce non-potable use by 50%. Eliminate non-potable use. WEc Credit 2: Innovative Wastewater Technologies OPTION 1 Reduce potable water use for building sewage conveyance by 50% through the use of non-potable water Strategy – Rainwater harvesting

FGBC Green Development Standard ver 6.0 Category 1: Protect Ecosystems and Conserve Natural Resources P-2: Conservation areas: Preserving land in a natural state allows for natural ecosystems to sustain their existence, particularly if large areas remain intact. Restoring and maintaining land area from a previously developed, significantly disturbed, invaded by exotics or pasture use to its historical natural habitat or other more appropriate habitat relating to current soils, and adjacent habitats is also important. P-4 Provide a vegetation & tree, topographical, soil, and wildlife/habitat study prior to design P-8: Preserve upland buffers to enhance preserved wetlands

FGBC Green Development Standard ver 6.0 Category 1: Protect Ecosystems and Conserve Natural Resources P-9: Preserve or provide ground water recharge areas P-11 Treating stormwater from neighboring sites or in pre-existing developments P-12 Low Impact Development Techniques

FGBC Green Development Standard ver 6.0 Category 2: Circulation C-2 Road design No full pavement cul-de-sacs Reduced roadway widths. C-8 Road/trail/ parking construction materials Pervious pavements Category 3: Green Utility Practices U-1 Minimize disturbance due to utilities U-3 Supply an irrigation system that uses stormwater or reuse water Category 4: Amenities A-4 Community food plot, garden parks

Sustainable Sites Initiative http://www.sustainablesites.org/ The Sustainable Sites Initiative is an interdisciplinary effort by the American Society of Landscape Architects, the Lady Bird Johnson Wildflower Center and the United States Botanic Garden to create voluntary national guidelines and performance benchmarks for sustainable land design , construction and maintenance practices.

Sustainable Sites Initiative Sustainable Sites Initiative Guidelines and Performance Benchmarks 2009: A compilation of current research, technology, and practices to provide technical guidance and performance benchmarks for sustainable land development and management practices Sustainable Sites Initiative Rating System (target publication date 2011): Sustainable landscape performance benchmarks with weighted credits and a recognition system Sustainable Sites Initiative Reference Guide (target publication date 2012): A user guide containing information from pilot projects that will explain credit requirements and provide resources to aid in creative problem solving.

Sustainable Sites Initiative The U.S. Green Building Council, a major stakeholder in theInitiative, anticipates incorporating the benchmarks into future versions of the LEED® (Leadership innergy and Environmental Design) Green Building Rating SystemTM. A report has been prepared listing 59 draft prerequisites and credits and their associated benchmarks, all based on a comprehensive review of applicable science and best practices in the industries involved.

Sustainable Sites Initiative Example Section 3.4 Prerequisite Reduce potable water consumption for irrigation 3.5 Credit Minimize or eliminate potable water consumption for irrigation 3.6 Credit Preserve and restore plant biomass on-site 3.8 Credit Reduce urban heat island effects 3.14 Credit Preserve existing topography 3.15 Credit Restore soils disturbed by previous development 4.9 Credit Design stormwater management features to be a landscape amenity

Cohasset L.I.D. Stormwater Retro-Fit Project Lily Pond is Cohasset Drinking Water Supply Control of discharges to Lily Pond required to protect public health and ensure safe Drinking Water Supply

Cohasset Stormwater LID Project Project Goals Reduce Nutrient Loading Reduce Other Pollution Suspended solids, organic pollutants, oils Help Prevent Catastrophic Contamination Public Education / Demonstration Project

Demonstration Raingarden at Lily Pond Treatment Plant Designed to intercept flows from parking lot discharging directly to Lily Pond. To be used as a Public Outreach Tool to educate community. Planted with a mix of communities and age plants. Cohasset Stormwater LID Project

Site prior to excavation Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Biorentention Soil Mixing Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Excavation Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Underdrain Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond Graded Filter

Placement of Bioretention Soil Mix Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Planting June 2005 Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

First Rain Storm Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

September 2005 Cohasset Stormwater LID Project Demonstration Raingarden at Lily Pond

Environmental and Community Protects unique or fragile habitats Reduces the pollution impacts of stormwater runoff Promotes aquifer recharge Provides opportunities to link wildlife habitats Conservation values are part of the planning process Can further goals of open space and community development plans The planning process inherently protects natural resources, minimizes direct and untreated stormwater runoff to water bodies, and promotes recharge to underlying aquifers. LID BENEFITS

Benefits for Implementing at Local Level Eliminate or minimize large detention basins Reduce Infrastructure requiring town maintenance (reduced clearing, grading, paving, pipes, ponds) Improve water quality Reduce flooding Preserve natural features Encourage “functional” landscapes SWM controls become part of property owners’ landscape reduces public burden for centralized SWM facilities on-lot cost and scale of maintenance is affordable An Introduction to LOW IMPACT DEVELOPMENT Alternative Approaches to Stormwater Management

AIA Florida is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. �ݺ�ߣ Required with AIA Florida as Registered Provider

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