Making LID Practical with Standard Details Lesley Brooks, P.E., CFM, ENV SP Boris Minot, EIT Spring TFMA-2016, Houston, TX Low Impact Development Match Existing Hydrology Reduce time of Conservation of concentration natural features Low impact design = Reduction in impervious area Reduce volume of runoff Developing Details • Dallas contracted Freese and Nichols and Hayden Consultants to develop up to 8 typical details for green roadway design Why Water Quality on Streets? • Roads and sidewalks = 33% of the total impervious surface Sources of Pollution Constituent Source ParticulatesSourcesPavement of wear, Pollution vehicles, the atmosphere, and maintenance activities Petroleum Spills, leaks, antifreeze, and hydraulic fluids, and asphalt surface leachate Nitrogen Atmosphere and fertilizer application Phosphorus Atmosphere and fertilizer application Copper Metal plating, bearing and brushing wear, moving engine parts, brake lining wear, fungicides, and insecticides Iron Auto body rust, steel highway structures such as bridges and guardrails, and moving engine parts Lead Leaded gasoline from auto exhausts (previously) and tire wear Zinc Tire wear, motor oil, and grease Cadmium Tire wear and insecticides Chromium Metal plating, moving engine parts, and brake lining wear Nickel Diesel fuel, gasoline, lubricating oil, metal plating, brushing wear, brake lining wear, and asphalt paving Manganese Moving engine parts Cyanide Anti-caking compounds in deicing salt Sodium, Calcium, Deicing salts and Chloride Sulphates Roadway beds, fuels, and deicing salts Why Water Quality on Streets? • Public Property/Public Examples • Part of walkable/ sustainable community Additional Benefits of LID • Reduced construction costs – Case Studies Analyzing the Economic Benefits of Low Impact Development and Green Infrastructure Programs (EPA, 2013) – Reducing Stormwater Costs through Low Impact Development Strategies and Practices (EPA, 2007) • Increased property values – A 2008 study in Seattle found neighborhoods with LID practices increased property values by 3.5-5% (The Effect of LOD on Property Values, Water Environment Federation) 2006 and 2012 Bond Program • $260 Million for Street and Transportation Improvements • Consultants judged on experience in green infrastructure (iSWM and/or Envision) • Expectation that roadways would be designed and built as complete streets Riverfront Blvd, Dallas $42.5 Million Riverfront Blvd, Dallas S. Lamar Street, Dallas S. Lamar Street, Dallas Lower Greenville, Dallas Lower Greenville, Dallas Elm Street, Dallas Elm Street, Dallas Elm Street, Dallas Creating Standard Details Looking to Others for Guidance • New York • Seattle • Portland • Philadelphia • San Francisco • Milwaukee • Washington D.C./DDOT • EPA Outreach Streets Department Sustainable Maintenance Development Department Trinity Public Works Watershed Urban Stakeholder Landscape Planning Input Architects Bioretention Options • High pollutant removal rates 85% Total Suspended Solids 60%/50% Nutrients (Total Phosphorus/Total Nitrogen) 35%-80% Metals (Cadmium, Copper, Lead, and Zinc 90% Bacteria 80% Hydrocarbons • Lower costs than other options ̽ = 7.30 ∗ ͐ͤ.ͭͭ or $6.80/cubic foot Where C = Construction, design and Permitting Cost ($) V = Volume of water treated (cubic feet) Brown and Schueler. 1997. The Economics of Stormwater BMPs in the Mid-Atlantic Region • Several options for integrating into design Dallas Considerations • Low infiltration soils Dallas Considerations • High intensity storm events www.floodsafety .com Dallas Considerations • Standard Maintenance Protocols • Contracted Maintenance BioretentionEnhanced/VegetatedCurbTree BoxExtension Filter Planter -With-CornerBioswale Parking -SingleSwale -Without-Mid-block-In Series Parking Bioretention Planter -With Parking -Without Parking Curb Extension -Corner -Mid-block Bioswale Enhanced/Vegetated Swale Tree Box Filter -Single -In Series Bioretention Planters Bioretention Planters Bioretention Planters Curb Extensions Curb Extensions Curb Extensions Bioswales Bioswales Bioswales Enhanced/Vegetated Channels Enhanced/Vegetated Channels Enhanced/Vegetated Channels Tree Box Filter Tree Box Filter Tree Box Filter Design Components Trench Drain Plants & Shrubs Edge Treatments Cleanout Overflow Structure Underdrain Energy Dissipators Signage Storage Media Maintenance and Inspections Upcoming Training End Goals • Improved water quality • Economic development • Walkable communities with character • A well maintained system Questions? Boris Minot, EIT [email protected] 2711 N. Haskell Blvd, 33 rd Floor 214-217-2228 Dallas, TX Lesley Brooks, P.E., CFM, ENV SP [email protected] 214-217-2248.