What is Storm Water?

Rain water that flows across the land is called storm water.  In vegetated areas such as forests, fields and wetlands, rain water seeps into the ground. However, when rain falls on paved and other hard surfaces it runs off and is conveyed by pipes and infrastructure directly to wetlands, streams, creeks and eventually to the Laguna de Santa Rosa.  Storm water runoff is generated by runoff from land and impervious areas such as paved streets, parking lots, and building rooftops during rainfall events that often contain pollutants in quantities that could adversely affect water quality.

What is Urban Runoff?

Urban Runoff is rain and any other water that passes through and out of developed areas (streets, parking lots, roof tops, etc.) into the storm drain system and eventually to creeks and other waters.

What Pollutants Are Commonly Found in Storm Water Runoff?

Any substance that is not naturally in rain can be considered a pollutant.  Potential pollutants can include:

  • Sediment: Bare soil/ground, construction, dirt from vehicles are all sources of sediment that can turn water cloudy making it less suitable for aquatic life and plants.  Sediment also carries pollutants such as chemicals, oils and metals as well.
  • Nutrients: Excessive nutrients such as phosphorus and nitrogen can over stimulate the growth of algae and other aquatic plants, affecting water quality, creating unpleasant odors and lowered dissolved oxygen levels from plant decay. Some forms of algae are also toxic to fish and other aquatic organisms, pets, and humans.  Fertilizers, animal wastes, detergents, road de-icing salts, automobile emissions, and organic matter are all contributors to excessive nutrient levels in storm water runoff.
  • pH:  Waters with very low (acidic) or very high (basic) pH are corrosive and can cause biological problems for aquatic organisms and fish. Cement used in concrete products and concrete pavements, chemical cleaners and acidic chemicals all can tribute to pH.
  • Metals:  Many metals, including lead, copper, and zinc, are commonly found in urban runoff. Dissolved metals, in very low concentrations, can be toxic to aquatic organisms, and interfere with reproduction.  Metals can adhere to and contaminate sediments in creeks and streams. Pesticides and paints, vehicle use and other materials contribute to metals in storm water. 
  • Oils and Grease: Oil and grease can be toxic to aquatic organisms at relatively low concentrations. Oil and grease from vehicles, streets and roadways, parking lots, gas stations and other equipment/machinery contributes to oils and grease in storm water.
  • Bacteria and other pathogens: Fecal coliform bacteria in water may indicate the presence of pathogenic (disease-causing) bacteria and viruses. Pet and other animal wastes, failing septic systems, livestock waste in agricultural areas and on hobby farms and fertilizers can all contribute fecal coliform bacteria.
  • Toxic Organic Compounds: Toxic compounds such as pesticides, cleaners, and paints are particularly dangerous in the aquatic environment and can be lethal to aquatic organisms. Excessive application of insecticides, herbicides, fungicides, and rodenticides, shortly before a storm, or application on impervious surfaces can result in the pesticide being carried to receiving waters. Cleaners, even those marked non-toxic and biodegradable, are toxic to aquatic organisms in very small quantities.  Many other toxic organic compounds can also affect receiving waters, including phenols, glycol ethers, esters, nitrosamines, and other nitrogen compounds. Common sources of these compounds include wood preservatives, antifreeze, and cleansers.

Is Storm Water Treated Before it Flows to the Laguna de Santa Rosa?

No, storm water flows do not receive treatment prior to entering the storm drain system and local creeks.

What is the Difference Between the Storm Drain System and the Sanitary Sewer System?

The storm drain system was built to collect and transport rain to prevent flooding in urban areas. Anything that flows or is discharged into the storm drain system goes directly into local creeks without any treatment. The sanitary sewer system collects and transports sanitary wastes from homes and businesses (sinks, baths, and toilets) plumbing systems to the City of Santa Rosa’s Laguna wastewater treatment plant where the wastewater is treated and reused.

Who Regulates Storm Water?

As authorized by the Clean Water Act (CWA), the National Pollutant Discharge Elimination System (NPDES) Permit Program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. The CWA was amended in 1987 and expanded from the wastewater treatment and industrial process water discharges to include Storm water discharges. In 1990, the Federal Environmental Protection Agency (EPA) issued rules governing the quality of storm water runoff.  These regulations require that storm water discharges be regulated under the NPDES program that regulates wastewater discharges. The NPDES Program is a federal program which has been delegated to the State of California for implementation through the State Water Resources Control Board.

The City was previously designated as a Small Phase II Municipal Separate Storm Sewer System (MS4) in 2003. The 2003 Order was adopted on April 30, 2003. In early 2013, Phase II cities including the City, elected to participate in the Phase I MS4 program.  The current NPDES permit was adopted by the North Coast Regional Water Quality Control Board on January 6, 2016.

What is the City’s Storm Water Management Plan?

In October 2005, the North Coast Regional Water Quality Control Board approved the City's Municipal Storm Water Management Plan (SWMP) to:

  • educate and inform the public about urban runoff pollution
  • encourage public participation in community and clean-up events
  • work with industries and businesses to encourage pollution prevention
  • require construction activities to reduce erosion and pollution
  • require developing projects to include pollution controls that will continue to operate after construction is complete
  • work with our own internal departments to ensure that our maintenance and development projects are designed to reduce pollution.

What Can Happen if I Dump Something Other Than Rainwater Into the Gutter or Storm Drain?

Putting anything into storm drains or creeks is more than inconsiderate – it’s against the law. Violation of the storm water ordinance is an infraction or misdemeanor at the discretion of the City. The City can require you to clean up the discharge at your expense. For continued violations, the City can take civil action.

Any intentional dumping in the right-of-way may also be subject to Penal Code 374.2(a), which carries fines. Anyone discharging materials that could cause harm to fish or wildlife may be subject to prosecution and fines up to $25,000 per day, per violation. (Refer to the California Water Code, California Fish and Game Code, U.S. Clean Water Act.)

If you see anyone illegally dumping within City Limits, you may report the problem to the Public Safety Department by calling 584-2611 or 584-2600.