Storm Water Pollution Prevention

Storm Water Pollution Prevention (NPDES)

Hawthorne has two drainage systems - the sewers and the storm drains. The storm drain system was designed to prevent flooding by carrying excess rainwater away from city streets out to the ocean. Because the system contains no filters, it now serves the unintended function of carrying urban pollution to the ocean. The entire City of Hawthorne drains into the Dominguez Channel. This channel begins as a covered storm drain at the Los Angeles International Airport, then becomes uncovered just north of Hawthorne Airport and eventually flows into Los Angeles Harbor near Wilmington.

Here is a little history lesson on how this flow pattern came to be. In the 1700s the northern portion of the Dominguez Channel was on the Sausal Redondo Ranch, which includes present day Hawthorne. To the south was the Rancho Dominguez, from which the channel derives its name. In the mid 1900s the Dominguez Channel was concreted to provide flood protection to the region. That is how the present day Dominguez Channel came to be.

Rainfall, especially the "first flush", carries industrial and household water mixed with urban pollutants, creating storm-water pollution. The pollutants include: oil and other automotive fluids paint and construction debris, yard and pet wastes, pesticides and litter.

Urban runoff pollution flows to the ocean through the storm drain system that takes water and debris straight from the streets to the ocean. Each day 100 million gallons of polluted urban runoff enter the ocean untreated, leaving toxic chemicals in our surf and tons of trash on our beaches.

Urban runoff pollution contaminates the ocean, closes beaches, harms aquatic life and increases the risk of inland flooding by clogging gutters and catch basins. Overall, storm water pollution costs the Los Angeles area economy millions of dollars per year.

What We Are Doing

The City of Hawthorne has implemented a number of programs to help reduce the amount of pollutants mixing with runoff. Here is a sample of these programs:

  • All residential and commercial streets including City owned and/or operated parking lots are included in regularly scheduled street sweeping.

  • There is a Stormwater Pollution Prevention Ordinance in place.

  • Approximately 600 businesses are inspected on a regular basis.

  • We routinely clean-out all of our City-owned storm drain catch basins.
    (If you see a catch basin that is full – please don’t hesitate to call us)

  • Implementation of Best Management Practices for all City construction and maintenance activities.

  • City employees routinely attend training to ensure awareness and use of BMPs on construction and maintenance projects.

  • We have implemented an active public outreach and education program.

  • We are now requiring special treatment systems for all high priority projects.

Many new building and site developments are now required to install filtration devices such as these:

These Bio-Filtration units are located on a privately owned and maintained large development in town. The unit captures all low flow water, trash and toxins. The interior of the unit contains: rocks, leaves and bark that allow for a natural filtration of toxins and other pollutants in the water. The device also captures trash left on the ground and is designed for easy trash removal and maintenance. The water filters down to a pipe that leads to the catch basin near by and the clean water then flows into the storm drain system. This device filters storm water everyday to remove trash, toxins, and more.

What You Can Do

As a resident or business owner in Hawthorne there are some simple steps you can take to help prevent stormwater pollution.

  • Vehicle Maintenance: Keep your vehicles in good running order and perform routine maintenance to prevent leaks from oil and other car fluids. Leaks from vehicles on the ground often times are a primary source of pollution in runoff.

  • Spills: If you experience or encounter a spill, don't hose it down into the gutter or storm drains. The best thing to do is clean it up with absorbent materials such as kitty litter. This allows for prompt cleanup of all spills. Then simply dispose of absorbent materials in trash.

  • Car Washing: Take your vehicle to a car wash instead of washing at home. If you choose to wash at home, divert the wash water onto your lawn or garden and use a biodegradable, phosphate-free detergent. Using a bucket (not a running hose) to wash and rinse your car, conserves water.

  •  Recycle your used oil: Oil doesn’t wear out and can be recycled to use again in engines and some motors, but also other uses as well.

AutoZone #5387 
13765 Hawthorne Blvd 
Hawthorne , CA 90250
(310) 644-8663

O’Reilly Auto Parts #1327
13601 Hawthorne Blvd 
Hawthorne , CA 90250
(310) 644-0034

  • HHW: Please dispose of hydraulic, transmission, and radiator fluids at a Household Hazardous Waste Facility.

    • Never clean paintbrushes or rinse paint containers into a street, gutter, or storm drain.

  • Yard Maintenance:

    • Fertilizers: Use organic or non-toxic fertilizers. There are a number of organic options at

      • Planet Natural’s organic fertilizers page

      • Extremely Green has some great options too

      • Don't over fertilize and don't fertilize near ditches, streams, or other water bodies.

    • Pesticides: Use non-toxic pesticide alternatives whenever possible. Organic Pesticides are a good option. Here are a few websites to check out:

    • Pet Waste:

      • Pick up after your pets. All of them. Pet waste from dogs and cats if left on yours or someone else’s lawn can easily end up in the storm drain and pollute the waters they enter.

    • Pool Maintenance: Make sure your pool is algae free and dechlorinated before pumping to the street. Please do not drain your salt water pools to the street. Salt water negatively impacts our native flora and fauna. Fresh water animals (such as frogs and tadpoles) will not survive any influx of salt water into their habitats.

Useful links


For Residents:



For Businesses

General information

Recycling information:

For schools:

Student education: