It is illegal to allow anything other than rainwater to be discharged to a storm drain.

Never allow landscaping materials to be transported to a street, gutter, parking lot, or storm drain. If over applied, spilled, or disposed of improperly, materials such as fertilizers, herbicides and pesticides can be harmful to water quality and creek habitats.

Individuals and businesses that improperly handle and dispose of non-stormwater materials down the storm drain are both subject to civil and criminal prosecution.

Best Practices: 

Fertilizers, herbicides and pesticides

  • Must be disposed of as hazardous waste.  Call (707) 565-DESK (3375) for more information and locations.
  • Check the weather and don’t spray if rain or high wind is forecasted.
  • Use natural non-toxic alternatives whenever possible.
  • If you must use traditional products, spot apply only.
  • Avoid application on hard surfaces, such as curbs and driveways.
  • Stay away from creeks, ponds, and ditches as a rule.  Spraying within 100 feet of these features requires a permit from the State.


  • Avoid overspray and over irrigation.
  • Fix leaks.
  • Use drip and bubbler irrigation.
  • Use low flow sprinkler heads to minimize overspray, evaporation, and runoff.

Yard Waste and Landscaping Materials

  • Keep material and debris out of the gutter and catch basins.
  • Protect bare soil.
  • Cover stockpiles and store chemicals away from rain and runoff.
  • Dispose of grass clippings, leaves, branches, sticks, or other yard waste by composting it or putting it in a yard waste bin.

Vehicle and Equipment Maintenance

  • Immediately clean up drips or small spills.
  • Separate hazardous wastes and use secondary containment for storage.
  • Use dry cleanup methods (i.e. broom or vacuum). Avoid hosing down or pressure washing work areas.
  • Separate hazardous wastes and use secondary containment for storage.

Are You Ready to Respond to a Spill?

  • Have a written plan.
  • Train employees annually on storm water regulations, spill response, personal safety, and hazardous waste handling and disposal.
  • Have spill cleanup materials onsite.
  • Have Safety Data Sheets for all products used.

How are the Storm Drain and Sanitary Sewer Systems Different?

  • Throughout urban communities, the storm drain system transports rainwater to local creeks, rivers, and the ocean. This system was created to prevent flooding within communities and homes.
  • All water and materials that enter the storm drain system are untreated.
  • The sanitary sewer is a plumbed system that transports used water from buildings to a wastewater collection and treatment facility, where the water and sewage is treated.
  • If you see an outdoor drain and are unsure of its use, assume it is a storm drain and do not discharge wash water to it.

Report Spills Here

Cloverdale: (707) 894-2150
Cotati: (707) 665-3605
Healdsburg: (707) 431-7000
Rohnert Park: (707) 588-3300
Santa Rosa: (707) 543-3800,
After Hours: (707) 543-3805
Sebastopol: (707) 823-5331,
After Hours: (707) 829-4400
Ukiah: (707) 463-6288
Unincorporated County of Sonoma: (707) 565-1900
Unincorporated Mendocino County: (707) 234-6679
Windsor: (707) 838-1006,
After Hours: (707) 838-1000

Releasing pollutants into the storm drain system or a waterway is prohibited by local ordinance, state, and federal law.

Have you seen this in your neighborhood?