Costs Design Construction Operation Maintenance

Transcription

1 LID Considerations Costs Design Construction Operation Maintenance LID Design Manuals New Hanover County, NC San Diego, CA City of Salinas, CA Washington, Puget Sound Partnership San Mateo Conventional Development Multiple Systems LID Development Conservation Minimization Soil Management Open Drainage Rain Gardens Rain Barrels Pollution Prevention Disconnected Decentralized Distributed Multi-functional 1

2 Construction Cost Comparison Conventional LID Grading /Roads $ 569,698 $ 426,575 StormDrains $ 225,721 $ 132,558 $300, $250, $200, SWM Construction Cost Comparison SWM Pond / Fees $ 260,858 $ 10,530 Bioretention / Micro $ - $ 175,000 Cost $150, $100, Total $ 1,086,277 $ 744,663 $50, Unit Cost $ 14,679 $ 9,193 Lot Yeild $- Green - LID Yellow - Conventional CLEAR,GRUB,GRADE S/D CONVEYANCE ROADWAY WORK CURB & GUTTER STABILIZATION (SEED) RIP-RAP FENCE/PRIME COST SIDEWALKS DRIVEWAYS Category LANDSCAPING (TYP) RAIN BARRELS BIORETENTION AREAS SWM PONDS SWM FEE IN LIEU Rain Garden Treatment Train Approach Rain Gardens Bioretention Cell Bioretention Cell Storm Drain System Grass Filter Strip 2

3 Somerset Cost Savings $780,000 Total Cost Savings Eliminated Curb / Gutter $350, stor ponds $650,000 Pipes / Structures $150,000 Added $370,000 for Rain Gardens No Cost Stuff 1. Site Design to Conserve Terrestrial Functions 2. Disconnection 3. Grading Techniques 4. Distributed Controls 5. Multifunctional Use of Space 6. Less Grading and Clearing Optimize the use of these smart design techniques Out of Sight Devices 3

4 Cost Comparison Proprietory BMP's Maintenance Burdens Device Type Unit Cost Main. Cost Annual Ab Tech Absrobant $ 5,000 $ 1,600 Bay Saver Hydrodynamic $ 6,700 $ 2,000 Vortechnics Hydrodynamic $ 12,000 $ 2,000 CDS Hydrodynamic $ 15,000 $ 2,000 Fossil Filter Filter Inlet Insert $ 5,400 $ 6,300 Stormceptor Hydrodynamic $ 34,570 $ 2,000 Stormtreat Filter Wetland $ 33,000 $ 4,500 Stormfilter Filter Cartrages $ 40,000 $ 5,000 4

5 Rain Garden longitudinal view showing overflow device. Rain Garden on a commercial project with turf grass near I-395 and Edsall Road. Maintenance Cost - $200 / Year 5

6 Perspectives on Implementing Low-Impact Developments since 1998 Waukesha, Wisconsin Use native species in restoring open spaces and in lot bioretetnion landscaping Home and Lot Sales Conventional Village of Jackson Lot Size: 7,000 8,000 ft 2 Price: low-mid $40,000 Low Impact Prairie Meadows Lot Size: 7,000 8,000 ft 2 Price: mid-high $50,000 Applied Ecological Services, Inc. 6

7 Advantages of LID Over Conventional Design Lessons Learned Nature Sells! Added Value of LID Results in: Lot Premiums Increased Sales Velocity Increased Sales Volume Reduced Debt Service Reduced Infrastructure Costs Biggest Obstacles to LID Local Ordinances and Knowledge / Experience of Local Building Officials & Consultants! High Flow Rate Filter and Infiltration Treats 90% of Total Annual Volume 7

8 A Comparison of Two Different Land Plans PROJECTED RESULTS FROM TOTAL DEVELOPMENT Total Site Conventional Plan Lot Yield 358 Linear Feet - Street 21,770 Linear Feet - Collector Street 7,360 Linear Feet - Drainage Pipe 10,098 Drainage Sections 103 (Inlets, Boxes, Headwalls) Estimated Total Cost $4.6 million Revised Green Plan , , $3.9 million LID vs CONVENTIONAL COSTS Summary of Cost Comparisons Between Conventional and LID Approaches ACTUAL RESULTS FROM PHASE ONE Total Site (engineer s estimate) Lot Yield Total Cost Cost Per Lot Conventional Plan 63 $1,028,544 $16,326 Green Plan ,523 $11,507 ECONOMIC AND OTHER BENEFITS FROM LOW-IMPACT DEVELOPMENT Higher Lot Yield Higher Lot Value Lower Cost per Lot Enhanced Marketability Added Amenities Recognition TOTAL ECONOMIC BENEFIT 17 additional lots $3,000 more per lot than competition $4,800 less per lot 80 percent of lots sold in the first year 23.5 acres of green space/parks National, state, and professional groups More than $2.2 million in savings. Source: Reducing Stor Costs through Low Impact Development (LID) Strategies and Practices, December 2007, US EPA. 8

9 YMCA Porous Concrete 9

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11 Bunt Mill Creek Projects Port City Java 11

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16 Rain Garden (1,500 ft 2 ) Principal (Mrs. Greene) 16

17 M a r i o n C o u n t y L I D P r o g r a m Case Study: Madera A Model Subdivision of LID Design Techniques Glenn Acomb, ASLA Department of Landscape Architecture Program for Resource Efficient Communities University of Florida 17

18 M a r i o n C o u n t y L I D P r o g r a m M a r i o n C o u n t y L I D P r o g r a m Case Study: Madera Location: Gainesville, Florida Size: 44 acres Developer: GreenTrust, LLC (MD) in partnership with the University of Florida Energy Extension Office 88 single-family homes on 44 acres (2.0 units/acre) Uses LID practices for resource efficiency Significant community open space and buffers Uncurbed roads and narrow right-of-way (50 ) Restrictions to protect hardwood tree canopy and understory vegetation Proximity to UF and trail connections All homes are EnergyStar, WaterStar & resource efficient Sustainable Design Techniques for the Community First tt to be approved via the City s Green Development tc Code Reasonably compact houses (2,200-2,600 2,600 s.f.) Limited clearing of lots; must submit site plan with tree locations Native plants and very limited turf Connectivity to University (1.5 mile; trail connection) Goal of zero discharge of stor on lots Minimally-sized community detention basin Required use of EnergyStar and WaterStar appliances + M a r i o n C o u n t y L I D P r o g r a m Sustainable Design Techniques for the Lot: Design Techniques of the Model M a r i o n C o u n t y L I D P r o g r a m Madera Model Center Landscape Design Existing Vegetation Existing Vegetation Limited clearing of site Limited turf (35% of conventional) Limited irrigation (50%); low-volume design Limited impervious cover (encouraged) - Pervious pavers for driveway & sidewalk and shared driveway for some lots Zero discharge of stor Capture of 1/3 roof stor to an infiltration tank; water garden in front yard natural area Use of natives and Florida Friendly plants; SJRWMD & Florida Yards & Neighborhood support Retained snags in rear yard buffer Model home displays an array of green products Road Rain Garden Entry Model Center Garage Tank Guest Parking Guest Parking Existing Vegetation Shared Driveway (pervious pavement) 18

19 M a r i o n C o u n t y L I D P r o g r a m Madera Model Center M a r i o n C o u n t y L I D P r o g r a m Madera Site Details Turf reinforcing in spare parking areas Eco-Stone pervious pavers in driveway Roof stor infiltration tank under spare parking Shared driveway and pavers Permeable pavers Model front yard Native plant information M a r i o n C o u n t y L I D P r o g r a m Madera Model Center M a r i o n C o u n t y L I D P r o g r a m Madera Home 2003 Water conservation information Rain Garden / Porous Pavement No turf, front-loading garage; edge ornamental plantings 19

20 M a r i o n C o u n t y L I D P r o g r a m Madera Home 2005 M a r i o n C o u n t y L I D P r o g r a m Comparison with Conventional: Site Design Techniques for the Lot Capital Costs: (2003/2004 dollars) Task Sustainable Conventional Sustainable Savings Clearing/Grading $1, $2, $ Utility Connection same same Natural Area Mulch $ $90.00 ($155.00) Landscape Area Mulch $ $ ($259.00) Landscaping $6, $6, Turf $ $2, $1, Irrigation $1, $1, $ Driveway* $6, $7, varies with material Infiltration Tank $1, ($1,032.00) Turf Reinforcing for Parking $ ($845.00) SUB TOTAL $18, $20, * Front-loading garage; very limited turf; extensive mulch; rain garden * Note: The driveway, if not shared, would cause an advantage of $5,294 in favor of the Conventional. If so, only in the maintenance per annum can the costs be recovered (in less than 3 years). Also, there should also be an adjustment of capital cost of the project-wide stor savings of reduced pond size due to the zero discharge at the lot (approx. $1,000 saved per lot). M a r i o n C o u n t y L I D P r o g r a m Comparison with Conventional: Site Design Techniques for the Lot Maintenance Costs: (annual costs, 2003/2004 dollars) Task Sustainable Conventional Sustainable Savings Landscape service (incl. mowing) $1, $3, $1, Pesticide applications by service $ (IPM) $ $ Irrigation $71.84 $ $ [31,602 gal.] [74,120 gal.] SUB TOTAL $1, $3, $1, Result: The approach to the maintenance considers landscape maintenance the residential site and 5 42 visits to visits for application of pesticide. Also there would be increased maintenance of the project-wide stor pond due to the greater depth of pond and greater accumulation of silt, debris and noxious plants in the bottom. Pilot Projects Willard Park Parking Area Power Plant Parking Lot Street Tree Filters Street Sweeping Demonstration Roof Leader Disconnect Museum Bioretention Retrofit Inlet Floatables Removal Inlet Timing Project Inlet Ponding Modification Permeable Pavers Installation Washington DC Navy Yard LID Retrofits 20

21 Porous Pavers Capturing Roof Runoff 21

22 Building 166 Permeable Pavement 22

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25 Navy Yard Rain Garden Navy Yard Tree box Don t Feed the Regulators!! 25

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