Through both the Stormwater Hotline and public events, the program receives many questions regarding stormwater pollution, as well as on the City’s Stormwater Program in general. The following are some of the most commonly asked questions:

About the System

Illegal Dumping

About the Program



Q: What is a catch basin?

A: A catch basin is a curbside receptacle whose sole function is to serve as a rainwater drainage device.

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Q: Are sewers and storm drains the same thing?

A: No. They are two completely separate drainage systems. Effluent in the sewer system receives extensive and thorough filtration prior to being discharged into the ocean. The storm drain system on the other hand, receives no filtration whatsoever, and discharges directly into the ocean untreated.

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Q: Do catch basins and storm drains get cleaned out?

A: Yes. The City’s Bureau of Sanitation Wastewater Collections Division maintains approximately 65,000 catch basins throughout the city. There are a number of problematic locations throughout the City where certain catch basins, because of either topographical location or from repeated illegal dumping, are cleaned with more frequency.

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Q: Why doesn’t the City clean out all of the catch basins right before a storm?

A: The City has over 65,000 catch basins to maintain. Vactor truck crews clean out clogged catch basins throughout the year as they are reported. Unfortunately there are just too many catch basins and not enough resources or crews to keep them all in proper functioning order. And although the County has a flood channel maintenance program, it simply can not keep up with daily illegal dumping of debris into the open channels.

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Q: Why doesn’t the City install filters or screens in front of catch basins?

A: It sounds like a good idea. But during a rainstorm, trash is quickly swept to the catch basin and any screen or filtration device placed in front of the catch basin would cause trash to accumulate and clog the grate, preventing proper drainage and end up flooding the street. With over 65,000 catch basins in the City of Los Angeles alone, and over 200,000 in Countywide, there would be far too many blocked catch basins to have crews cleaning them as the rain falls.

There are new technologies being developed in the form of filtration or screening devices to be installed and inserted inside catch basins. The Stormwater Program Engineering groups are currently evaluating these new technologies for consideration.

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Q: Why isn’t a net/fence/barrier installed at the end of the storm drain channel to catch all of the trash?

A: The county manages the flood channels and, in fact, Ballona Creek does have a net near in place near the discharge point. Unfortunately, this net only catches most of the trash that floats — all of the toxins like pet waste, used oil, pesticides, fertilizers, etc. flow through the net and straight into the ocean. There have been occasions where, because of the combined heavy rainflow and the large amounts of trash and debris—the net simply breaks.

There are currently other methods being studied for low-flow debris removal and filtration.

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Q: Why doesn’t the City build a stormwater treatment facility?

A: Such a facility would be extremely costly to build and maintain. And, the massive amount of water coming through the facility during a rainstorm would easily overtax the system.

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Q: What kind of pollutants are found in the storm drain system?

A: Paint thinner and paint products, motor oil, pesticides, Styrofoam cups, paper, human and animal feces, antifreeze, golf balls, dirty diapers, and dead animals —are but a few of the pollutants found in the system on a daily basis.

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Q: How much water passes through the system?

A: On a typical dry summer day, an average of one million gallons flows through the system. This flow comes from overwatered lawns, fire hydrant pressure releases, and car washes throughout the region, just to name a few.
In a heavy rainstorm, this flow can increase to billions and billions of gallons.

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Q: When was the storm system built? Why?

A: Following a devastating flood in 1938 resulting in 119 deaths and over $40 million dollars in property damage, the Army Corps of Engineers began the construction of the storm drain system. Initially, the Ballona Creek and Los Angeles River flood channels (in the Los Angeles area) were constructed with outlying channels such as the Arcadia Wash, etc. being built throughout the 40’s and 50’s as the urban areas grew in population.

For a visual explanation, refer to the storm drain history and construction sections.

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Q: Why do the channels have to be concreted? Can’t they be natural waterways?

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Q: What is the City of Los Angeles doing about illegal dumping?

A: With the recent passing of the City of Los Angeles’ Stormwater Ordinance, it is now considered an environmental crime to knowingly dump or discharge hazardous materials into storm drain catch basins and the City can impose stiff fines on the perpetrators if they are caught.

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Q: How much does the City spend on fighting illegal dumping?

A: The City spends approximately $1million per year responding to and cleaning up of illegally dumped waste materials.

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Q: I see people dumping their used oil into storm drains all the time. What can I do?

A: Dumping used oil is illegal. One gallon of motor oil can pollute 250,000 gallons of drinking water. To report the problem, call 1-800-974-9794. To take your used, but uncontaminated (mixed with other fluids) motor oil to a recycling center, call 1-800-98-TOXIC.

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Q: What happens if I see a neighbor, or know someone who’s throwing trash into a storm drain?

A: Storm drains are for the sole purpose for rainwater overflow. Dumping trash, pollutants and debris in the catch basins is illegal and is a federal violation of the Clean Water Act of 1972 as well as the City of Los Angeles’ Municipal Code. If it’s a neighbor, they may not understand the catch basin’s direct connection to the ocean. If you have an amicable relationship with him/her, it may be just a matter of informing and making them aware of its environmental impact.

If it is someone who you feel is knowingly violating and repeatedly dumping into storm drains, please call the City of Los Angeles, Department of Public Works, Stormwater Management Division at 1-800-974-9794; or the Los Angeles County Department of Public Works at 1-800-303-0003.

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Q: I have some paint/thinners/chemicals/ at home that need to be disposed of. Where can I take these?

A: The County of Los Angeles conducts monthly Household Hazardous Waste roundups. Call (800) 98-TOXIC for the collection and drop-off location nearest you.

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Q: What is the fine/penalty for illegal dumping?

Q: How much trash gets washed up on beaches?

A: Every year, roughly 40 tons of trash and debris.

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Q: Where do funds for the storm water pollution control program come from?

A: Every taxpayer is pays an average of $24 on his/her property tax. This tax forms the Stormwater Pollution Abatement Charge (SPAC) that funds the program. The fee is determined by the amount of runoff from each property in the City of Los Angeles.

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Q: As an LAUSD teacher, what kind of educational programs or informational materials does the City offer for students?

A: There are variety of programs for elementary school children on how to prevent Stormwater pollution. WaterCycle is an interactive school assembly and EcoTours is an educational walk program coordinated by environmental educators. To receive more information, call 1-800-974-9794.

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Q: I have often seen stencils over the catch basins. How do I get a stencil for a catch basin near me?

A: Call Heal the Bay at (800) HEALBAY for more information on the neighborhood stenciling program.

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Q: I have some paint, paint thinner, chemicals, batteries at home that I need to dispose of. How do I do it?

A: Paints, paint thinner, chemicals and batteries are all household hazardous waste that need proper discarding. Call for your nearest Hazardous and Toxic Waste office — LA City, 1-800-98-TOXIC or LA County, 1-888-CLEAN-LA.

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Q: I wash my own car. How can I be environmentally responsible?

A: The best place to wash your car is to pull it up on the lawn or gravel. Use biodegradable soaps to wash you vehicle, using as little water as possible. Shut off water while washing your car, then rinse. Remember not to leave your car on the lawn. We would highly recommend going to a full or self service car wash because the used water is recycled.

For a complete how-to on carwashing, refer to the Car Wash Fundraiser Guide.

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Q: Yard clippings leaves are natural, so they don’t cause any problems, right?

A: Grass, leaves and yard clippings that are repeatedly swept into catch basins can clog the drain, causing flooding and the potential for becoming a breeding ground for rodents and insects. Additionally, grass and leaves decompose and once yard clippings enter into the ocean, they contribute to new plant growth which deprives fish of their oxygen, and the fish die.

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Program History | What is Stormwater Pollution? | Program Components |
Public Education | The Storm Drain System | Pollution Abatement |
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