Storm Water Management Program

Only Rain Down the Drain!

Report Illicit Discharge
(209) 895-8060

The Goal of the City's Storm Water Management Program is to ensure that the City's storm drainage system is properly working to help prevent flooding and to protect Water Quality!


Storm Drain System vs Sanitary Sewer System


Storm drain and sanitary sewer systems have two distinct functions and it is very important for people to understand the difference.

Catch basins are the entryway into the Storm Drain System and are typically located at the bottom of a hill or at street corners.

This system collects and transports water and other liquids away from these areas and out to a local waterways (Salado Creek and San Joaquin River) UNTREATED. Please Note: The Storm Drain System does not remove pollutants from water before it is discharged into our streams and rivers.


The Sanitary Sewer System collects wastewater from indoor plumbing such as sinks, toilets, washing machines, and floor drains where it is transported through underground pipes to a sewage treatment plant. The sewer treatment plant removes many pollutants from wastewater before it is discharged back into the river. Improper disposal of wastes is very harmful to the environment, hazardous to public health, and violates state and federal law.

Stormwater Radio Ads - Outreach & Education Campaigns

Storm Drain System vs Sanitary Sewer System

What Pollutes Storm Water?

  • Used Oil
  • Pet waste
  • Irrigation runoff
  • Dirt piles on street/driveways
  • Washing cars on street/driveways
  • Yard clippings, leaves, and green waste
  • Improperly disposing of paint & hazardous materials
  • Litter on ground
  • Pesticide used in gardens

***Please Note: All household hazardous wastes should be taken to the Permanent Household Hazardous Waste Consolidation Facility operated by the County located on Morgan Road, Modesto or click here to obtain further information on upcoming events and disposal options: Recylcing-Solid Waste Web Page.

San Joaquin Valley Storm Water Quality (SJVSWQ) Partnership

In an effort to ensure that compliance with all stormwater regulations, the City of Patterson is a member of the SJVSWQ partnership.  The partnership works together through a Cost Sharing Agreement to expand the program.  For more information regarding this partnership and to obtain more information regarding the stormwater requirements, please visit the SJVSWQP website by clicking here: 

SJVSWQP Website