Presentation on theme: "LID BMPs Presented by: The Low Impact Development Center, Inc. A non-profit water resources and sustainable design organization www.lowimpactdevelopment.org."— Presentation transcript:
LID BMPs Presented by: The Low Impact Development Center, Inc. A non-profit water resources and sustainable design organization www.lowimpactdevelopment.org
The Low Impact Development Center, Inc. has met the standards and requirements of the Registered Continuing Education Program. Credit earned on completion of this program will be reported to RCEP at RCEP.net. A certificate of completion will be issued to each participant. As such, it does not include content that may be deemed or construed to be an approval or endorsement by RCEP.
The purpose of this presentation is to describe the Best Management Practices (BMPs) commonly used in Low Impact Development. At the end of this presentation, you will be able to: Describe the most commonly used LID BMPs Explain what design variations exist and how they can be deployed. Purpose and Learning Objectives
1.2.3. Treatment Train: BMP Hierarchy Source controls Conveyance controls End of pipe controls LID is Part of the Watershed Toolbox!
Structural and Non-structural Vegetation Hardscape Proprietary Buffers Amendments Bioretention Permeable pavements Rainwater harvesting Green roofs Proprietary systems Classification and Examples
Importance of Buffers Reduce nutrients Reduce thermal impacts Provide habitat Protect wetland hydrology Bay guidance ~ 100 ft., MA and CT: sliding scale 50 to 200 ft.
Types/Definitions Reforestation: Replacement Aforestation: Establishment Riparian Buffers: Corridors for filtering/uptake/thermal/disconnection **Some States, such as Maryland, have strict forest conservation and stream buffer regulations that effect SWM and other construction
Compost amendments and filter soxx Runoff, Nutrient, and Sediment Reduction Goals! Recycling Aesthetics
NRDC – Santa Monica, CA Cisterns at NRDC Santa Monica Office Cisterns installed beneath planting beds. Collected rainwater is added to greywater collection system and used for toilet flushing and irrigation. Building uses duel-flush toilets, waterless urinals, and drought-tolerant plants. 60% reduction in potable water demand.
Construction Cost Elements Rainwater Harvesting Rain barrels cost $100-$300 Cisterns cost several hundred to several thousand dollars Components include: Storage tank Downspout flow diverter Pre-tank filtration Post-tank treatment (if needed) Distribution system (e.g., spigot and hoses, plumbing) Costs can vary significantly depending upon storage size, tank material, and location (above or below ground)
Green Roof Layers Waterproofing membrane Root barrier (if the waterproofing is not certified as root resistant) Drainage layer Separation layer Growth media layer Plants Courtesy: Roofscapes
Green Roof Benefits: Rainwater capture Energy savings Extended membrane life
Green Roof Construction Cost Elements Costs range from $15-$20/sf based on the inclusion of: Growing medium Plants Drainage layer Insulation layer Root barrier Waterproof membrane Leak detention layer (optional) Costs can increase because of equipment, material availability and scheduling
Slide courtesy of the Center for Neighborhood Technology The temperature above Chicago’s City Hall green roof averages 10 -15°F lower than the black tar roof. Difference can be 50°F or greater during the summer. Energy savings of $3,600 per year. Urban Heat Island
Source: Green Roofs for Healthy Cities www.greenroofs.org Ford Motor Company Rouge River Manufacturing Complex – Dearborn, MI
Pilot Study: Modular Tray System System Characteristics: Flexibility Size of system Placement configuration Ease of installation Coarse stone ballast Retrofit designs Use existing drains Specialized outlet designs Detention time and Flow rate Minimize clogging Coarse Stone Ballast (expanded shale) Orifice Outlet Controls
Demonstration: Retrofit Hydraulic Structure Design System Characteristics: Ease of installation o Retrofit designs o Storage on roof surface o Use existing drains Outlet Design: o V-notch weir Control flow rates Temporary storage o Grated weir cover Intercept debris Minimize clogging Reduce maintenance Existing Roof Drain V-Notch Weir Plates Grated Weir Cover
Source: Army: Public Works Technical Bulletin 200-1-62
Discussion Designs do not have to be complicated Field adjustments Materials availability
Bioretention cell retrofits Bioretention strip in parking lot median Permeable paver cells Street tree filters Roof leader disconnect Rain barrels LID Features Constructed Washington Navy Yard
Construction WNY special design requirements National Priority List facility HDPE liners Perforated pipe under drains Bioretention cells - overflow weirs Native, drought and flood resistant plantings
Willard Park Bioretention The Willard Park parking area was retrofitted during the storm sewer system rehab project using bioretention as the main storm water LID technique
Willard Park Bioretention Strip Liner Installation
Willard Park Bioretention Strip Under drain and soil installation