Stormwater Quality

Stormwater Quality

watershed pic

The City of Westlake Village believes that protecting and enhancing our local water quality is of great importance. The City lies within the drainage boundary of the Malibu Creek Watershed. Nearly all the City’s land drains into Westlake Lake and Triunfo Creek ultimately leading to Malibu Creek, Malibu Lagoon, and the mighty Pacific Ocean.  

Water draining into the streets goes directly to the lake and creeks via the storm drain system and can pick up pollutants along the way. Runoff from urban and suburban areas is likely to contain the following:

  • Fertilizers and pesticides leached from lawns
  • Oil and antifreeze leaked from cars and washed off driveways
  • Bacteria, viruses, and organic matter from pet waste
  • Household hazardous wastes
  • Sediment from construction
  • Trash and debris

The City of Westlake Village, along with surrounding cities and the County of Los Angeles, is proactive when it comes to protecting the quality of our water. Under the National Pollution Discharge Elimination System (NPDES) Permit program, the City is working to prevent urban stormwater pollution.

NPDES Programs

The Los Angeles Regional Water Quality Control Board is currently coordinating with municipalities and agencies to develop the sixth five-year cycle of the Los Angeles Countywide NPDES Permit (Permit). In the interim, the City of Westlake Village continues to operate under the fifth five-year cycle of the Permit, adopted on November 8, 2012 and expired on December 28, 2017. The Enhanced Watershed Management Programs (EWMPs), approved in 2016, form the basis for implementation of the NPDES Permit.  The City of Westlake is a member of the Malibu Creek Watershed EWMP Group, along with the cities of Agoura Hills, Calabasas, Hidden Hills, the County of Los Angeles and the Los Angeles County Flood Control District. The goals of the EWMPs are to implement control measures to achieve water quality objectives, protect water body beneficial uses, provide flood protection, recreational uses, water supply, and community enhancements. (View the Malibu Creek Watershed EWMP.)

Total Maximum Daily Loads

The City is subject to several Total Maximum Daily Load (TMDL) designations. TMDLs are used to help restore impaired water bodies by establishing a maximum amount of a pollutant allowed to enter a given waterbody while meeting water quality standards for the pollutant. The City must meet requirements for the following TMDLs:

  •  Trash
  • Bacteria
  • Nutrients
  • Sediment

 Minimum Control Measures

The City implements the following NPDES Permit Minimum Control Measure (MCM) programs.

Public Outreach & Participation

The City is dedicated to get the word out about pollution prevention, incorporating facets for outreach to communities, businesses, corporations, and schools. We need the community’s help to reduce pollutants in stormwater runoff through simple changes in daily living.

How You Can Help!

  • Participate in a local clean-up event hosted by Heal the Bay, the California Coastal Commission, or the Surfrider Foundation
  • Allow swimming pool water to sit for 10 to 14 days and test for absence of chlorine before discharging
  • Always dispose of cigarette butts into appropriate trash receptacles
  • Do not dump anything into the streets, gutters, or catch basins
  • Do not fertilize or use pesticides directly before rain or near ditches, gutters, or storm drain inlets
  • Find out more about project pollution prevention on the LA County Watershed Management Division website
  • Install drip irrigation to reduce water use in your garden
  • Properly maintain your car so it doesn’t drip fluids
  • Sprinkler water, hosing of sidewalks, and rainwater will carry everything in the streets (grass clipping, motor oil, fertilizers, pesticides, paint thinners, etc.) directly into our lake
  • Take advantage of locally available Household Hazardous Waste Programs by calling City Hall at 818-706-1613.
  • Use de-chlorinated pool water to irrigate landscaping
  • Use organic or non-toxic fertilizers and pesticides
  • Wash your car at the car wash to keep excess detergents and street trash from entering the storm drain system
  • Wash your car where the soapy dirty water will drain to a grassy area where the dirt and nutrients (soap contains nutrients!) will be used by plants and grasses
  • When you walk your dog, remember to bring a bag and clean up after it

Illicit Connection & Discharges

lake drains picThis program is designed to identify and terminate illegal connections and discharges into the storm drain system. If you would like to report an illicit discharge into our storm drain system or onto any public street, submit a request on the by clicking on the City Care logo to the left on a computer or at the bottom of the page on your mobile device. You may also call the countywide 24-hour hotline at (888) CLEAN LA. For incidents that endanger human health and other emergencies, call 911.

Development Planning

This program is designed to minimize the stormwater quality impacts due to new developments through the use of smart growth practices. The program contains specific requirements for developers to follow, including environmentally aware site planning and implementation of facilities to treat stormwater prior to discharge into the public storm drain system.

Development Construction 

This program is designed to minimize the stormwater quality impacts due to development construction. The program contains specific requirements for contractors to follow in order to minimize off-site transport of sediments and pollutants during construction.

Public Agency Activitieswater public agency pic

This program is designed to minimize stormwater quality impacts due to public agency activities such as public landscaping, street maintenance, and construction projects. In addition to applying the development planning and construction requirements to City projects, the City also conducts weekly street sweeping, annual catch basin clean-outs, storm drain stenciling, and as-needed debris removal from open channels and landscaped areas.

Business Inspections

The permit requires that the City inspect all restaurants, automotive service facilities, retail gasoline outlets, automotive dealerships, and industrial facilities for compliance with discharge prohibitions through proper implementation of stormwater best management practices. The inspections are to occur, and have been completed, twice during the current five-year permit cycle and once in the interim of the issuance of the new five-year permit. For information on how to become an Ocean Friendly Restaurant visit the Surfrider Foundation webpage.