Water Quality Issues

Stormwater and urban runoff is generated when rain and other water sources come into contact with (mostly impervious) land surfaces, and are collected and conveyed through streets and the storm drain system, and ultimately flow into rivers, creeks, and beaches throughout the Los Angeles region.  As the water comes into contact with various land surfaces, it washes off, and carries with it, a range of pollutants associated with the urban environment.  These pollutants include metals, bacteria, toxics, and other contaminants.   One impact of these pollutants is the compromising of the beneficial uses of the surface waters such as water supply, recreation, and fish consumption, among others.

The 1972 Federal Clean Water Act (CWA) established the National Pollutant Discharge Elimination System, or NPDES Program to regulate the discharge of pollutants from point sources to waters of the United States. Under Amendments to the Clean Water Act, the United States Environmental Protection Agency (USEPA) developed Phase I of the NPDES Storm Water Permitting Program in 1990, which established a framework for regulating municipal and industrial discharges of stormwater and non-stormwater. Within the State of California, the Regional Water Quality Control Boards issue Orders implementing CWA requirements, specifically as they relate to municipal storm drain systems.  The first Los Angeles countywide permit was adopted in 1990; the current version of the permit was adopted in 2012.  The 2012 permit included requirements associated with Total Maximum Daily Loads (TMDLs) for each pollutant impairing the water quality standards in the region’s water bodies.

To comply with the permit requirements, municipalities were granted the flexibility to develop Watershed Management Programs to identify customized strategies, control measures, and stormwater “Best Management Practices”, often simply called BMPs.  Program requirements were to meet TMDL requirements and to reduce the discharge of pollutants to the “maximum extent practicable.”  Municipalities were also given the option to develop Enhanced Watershed Management Programs, which would include multi-benefit, multi-jurisdictional regional projects, requiring, and allowing for, additional time to implement.

In the Los Angeles River Watershed (including the San Gabriel River Watershed, at times managed to be tributary to the Los Angeles River), municipalities have formed a number of Watershed Management Programs and Enhanced Watershed Management Programs.  These are described below:

Program NameMunicipal (Permit) Participants
Upper Los Angeles River EWMPAlhambra, Burbank, Calabasas, Glendale, Hidden Hills, La Canada Flintridge, Los Angeles, Montebello, Monterey Park, Pasadena, Rosemead, San Gabriel, San Marino, South Pasadena, Temple City, County of Los Angeles, County Flood Control District
Upper Los Angeles River Reach 2 WMPBell, Bell Gardens, Commerce, Cudahy, Maywood, Huntington Park, Vernon, County Flood Control District
Lower Los Angeles River WMPDowney, Lakewood, Long Beach, Lynwood, Paramount, Pico Rivera, Signal Hill, South Gate, County Flood Control District
Rio Hondo/San Gabriel River EWMP Arcadia, Azusa, Bradbury, Duarte, Monrovia, Sierra Madre, County, County Flood Control District
Upper San Gabriel River EWMPBaldwin Park, Covina, Glendora, Industry, La Puente, County, County Flood Control District
East San Gabriel Valley WMPClaremont, La Verne, Pomona, San Dimas
Lower San Gabriel River WMPArtesia, Bellflower, Cerritos, Diamond Bar, Downey, Hawaiian Gardens, La Mirada, Lakewood, Long Beach, Norwalk, Pico Rivera, Santa Fe Springs, Whittier, County Flood Control District

In addition, the following cities submitted individual WMPs

  • Compton (Compton Creek)
  • El Monte (Los Angeles River and San Gabriel River)
  • Irwindale (Los Angeles River and San Gabriel River)
  • La Habra Heights (San Gabriel River)
  • San Fernando (Los Angeles River)
  • South El Monte (Los Angeles River and San Gabriel River)
  • Walnut (San Gabriel River)
  • West Covina (San Gabriel River)