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Low Impact Development Introduction Moving towards Technology Based Landscapes, Streetscapes, and Infrastructure. Low Impact Development Green Infrastructure Green Highways Partnership. Low Impact Development (LID). Hydrology based distributed site design approach
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Low Impact Development IntroductionMoving towards Technology Based Landscapes, Streetscapes, and Infrastructure Low Impact Development Green Infrastructure Green Highways Partnership
Low Impact Development (LID) Hydrology based distributed site design approach • Reflects landscape and ecosystem function • Uniform or decentralized • Replicate function instead of mitigation • Multi-functional landscapes and infrastructure • Multiple regulatory and resource objectives
CHAPTER 26 CFR - WATER POLLUTION PREVENTION AND CONTROL • SUBCHAPTER I - RESEARCH AND RELATED PROGRAMS • § 1251. Congressional declaration of goals and policy. (a) Restoration and maintenance of chemical, physical and biological integrity of Nation's waters; national goals for achievement of objective. • Ecosystems Based • Technology-forcing • Comprehensive Research • Total Maximum Daily Load
Origins • Initiated by Prince George’s County in mid 1990’s • LID Center formed 1998 • EPA LID Manual 2000 • DOD LID Manual 2004 Subsequent PWTB • NCHRP Research 2006 • Federal State and Local Programs Regulatory and Go Green!!
Get Ready! • LID techniques will be the foundation of EPA Green Infrastructure Strategy • Federal Energy Legislation (438) • Highway Reauthorization • Everything is going green!
Defining LID Technology • Conservation (Watershed and Site Level ) • Minimization (Site Level) • Strategic Timing (Watershed and Site Level) • Integrated Management Practices (Site Level) Retain / Detain / Filter / Recharge / Use • Pollution Prevention
1. Conservation Plans / Regulations Large to Small Scale! • Local Watershed and Conservation Plans • Forest (Contiguous and Interior Habitat) • Streams (Corridors) • Wetlands • Habitats • Step Slopes • Buffers • Critical Areas • Parks • Scenic Areas • Trails • Shorelines • Difficult Soils • Ag Lands • Minerals
2. Minimize Impacts • Minimize clearing • Minimize grading • Save A and B soils • Limit lot disturbance • * Soil Amendments • Alternative Surfaces • Reforestation • Disconnect • Reduce pipes, curb and gutters • Reduce impervious surfaces
3. Maintain Time of Concentration • Open Drainage • Use green space • Flatten slopes • Disperse drainage • Lengthen flow paths • Save headwater areas • Vegetative swales • Maintain natural flow paths • Increase distance from streams • Maximize sheet flow
4. Storage, Detention & Filtration “LID IMP’s” • Uniform Distribution at the Source • Open drainage swales • Rain Gardens / Bioretention • Smaller pipes and culverts • Small inlets • Depression storage • Infiltration • Rooftop storage • Pipe storage • Street storage • Rain Water Use • Soil Management**
5. Pollution Prevention 30 - 40% Reduction in N&P Kettering Demonstration Project • Maintenance • Proper use, handling and disposal • Individuals • Lawn / car / hazardous wastes / reporting / recycling • Industry • Good house keeping / proper disposal / reuse / spills • Business • Alternative products / Product liability
Where is all this going • Hydromod • Watershed Based Approaches • Drivers and Implementation
Green Infrastructure • Use of community public and private open space for integrated network of stormwater facilities. Non-structural and structural • Proliferate micro-scale techniques in an effective manner throughout the watershed
Green Highways Partnership • The Green Highways Partnership (GHP) is a voluntary, public/private initiative • integrated planning: watershed! • regulatory flexibility • market-based rewards • “Better than Before”
Imperviousness & Threshold Theories It’s not so simple - very complex!
Figure 2: Showing the lack of mitigating influence of structural BMPs on biologic conditions in Puget Sound lowland streams (Horner and May, 2000). Note, “w/BMPs” refers to structural facilities only. [Honer / May 2001]
A few Issues! • How we see the world (without the meds) • Political and Economic Drivers • Institutional (Been there done that) • Technology and Materials
How well do we maintain the ecological integrity (functions) of aquatic systems (small streams)? Scale / Spatial / Temporal / Species Velocity Frequency Runoff Evaporation Ground Water Flow Duration Rain Intensity Flow Regime Nutrients Temperature D.O. pH Turbidity Organics Toxics Chemical Variables Ecosystem Integrity Canopy Siltation Gradient Substrate Current Instream Cover Sinuosity Width/Depth Channel Morphology Soils Stability Riparian Vegetation Habitat Structure Biotic Factors Disease Reproduction Feeding Predation Competition Energy Sources Sunlight Nutrients Seasonal Cycles Organic Matter 1&2 Production
Capacity Amenity The Good Old Days! Traditional Urban Drainage Sustainable Urban Drainage Water Quality Capacity Stahre, 2006
Conventional Ultra-Urban Retrofit • Space • Cost • Inefficiency • Pollution • Maintenance • Safety Creating Blackholes of Infrastructure Stormwater Competes With Other Programs
Stormwater regulations in a highly impervious world Why do we need LID Now? • Precision • Scale • Technology
MUSIC Monash U
Stormwater Drinking Water Decentralized Controls are Holistic and Watershed Based Wastewater
N2 AIR NH3 RAINFALL EVAPOTRANSPIRATION PARTICULATES ADSORPTION DENITRIFICATION BIOLOGICALFIXATION PLANTMATERIALS RUNOFF RUNOFF VOLITILIZATION METALS, NUTRIENTS MULCH SANDYSOILMEDIUM AMMONIFICATION NO3 NITROGEN FIXATION NH4 DENITRIFICATION NO2 DRAIN INFILTRATION RECHARGE NITROGEN CYCLE FOR BIORETENTION
SMOG RAINFALL HEAT/ LIGHT ET PICP Open-graded base s dog (optional)
Permeable Walks Reforestation Soil Amendments Bioretention Green Strategies
Washington, DC Seattle, WA 2nd Avenue SEA Street. Photo courtesy of Seattle Public Utilities. Award winning Barracks Row Green Factor Rating Systems Context Sensitive Solutions using lid to reduce inflow to combined sewer systems
Builder/Developer/Institution Land Use Economic and Design Requirements Localized Sustainable Development Industry Recognized Standards Local Community Codes/Ordinances and Watershed Requirements LID Fits with all current rating systems! Its good business!