Los Angeles' Innovative Clean and Green Approach

Stormwater runoff has the potential of introducing pollutants (pathogens, bacteria, trash, oil and grease, suspended solids, metals, gasoline and other toxics) to the stormwater conveyance system and receiving water bodies. Pollutants of concern from stormwater runoff can impact the beneficial uses of receiving water bodies, are found at elevated levels in sediments, and have the potential to bioaccumulate in organisms, and these measurable inputs of the pollutant are at a concentrations or loads considered potentially toxic to humans and habitats. The City of Los Angeles Green Infrastructure Program includes greening streets to improve the beneficial and recreational uses of receiving water bodies, reduce potential risks for human safety and health, reduce beach closures, preserve aquatic marine and plant habitats, and benefit the tourism industry. The City of Los Angeles contributes to four major watersheds: Los Angeles River, Ballona Creek, Santa Monica Bay, and Dominguez Channel.The Green Infrastructure Program assists the City in complying with Total Maximum Daily Loads (TMDLs) for bacteria, metals, toxics, nutrients, and other pollutants, and will help meet the new requirements of the National Pollutant Discharge Elimination System (NPDES) municipal stormwater permit. In addition, the projects from this program will add water to the aquifer (recharge the groundwater). The Watershed Protection Division has been working collaboratively to implement the various components of the Green Infrastructure Program, which include:• Institutional changes by all City departments to include green infrastructure• Adoption and implementation of the Low Impact Development Ordinance.• Three guidance manuals prepared for the City of Los Angeles Rainwater Harvesting Program:▪ Volume 1: “Urban Greening Policies and Standards.”▪ Volume 2: “Green Streets & Green Alleys Design Guideline Standards.”▪ Volume 3: “A Homeowner's ‘How-To’ Guide.”• Development of seven standard plans for Green Streets (the 1st of their kind in the country).• Development of a green infrastructure database, web site, and monitoring program for tracking the performance of all green infrastructure projects in the City.Implementation of the City of Los Angeles Green Infrastructure Program has been a great challenge for the past several years. The Riverdale Avenue Green Street Project is reviewed here in detail as a case study of Green Street Best Management Practices (BMPs) that improve the water quality of and control stormwater runoff. This case study reviews the performance of several different BMP technologies, including Infiltration Swales, Infiltration Galleries, Dry Wells, Permeable Pavement, Filtration Screens and BioFilters, which were installed in the urban setting of Riverdale Avenue.This case study discusses the City's experience in carrying out the Green Infrastructure Program and future City-wide Green Street projects. The lessons learned will: 1) provide a better understanding of designs utilizing green street elements; 2) assist others in developing and implementing green street projects by employing similar strategies; and 3) promote the multiple benefits that can be derived by managing stormwater with green street elements.