Walnut Creek prohibits illicit discharges to the storm drain system under its Municipal Regional Stormwater NPDES Permit. Violations can result in significant fines, cleanup cost recovery, and referral to the Regional Water Quality Control Board for state-level enforcement.
Under the Municipal Regional Stormwater NPDES Permit (MRP) and Walnut Creek Municipal Code, it is unlawful to discharge any substance other than uncontaminated stormwater into the city's storm drain system. Illicit discharges include dumping motor oil, antifreeze, paint, solvents, pesticides, or any hazardous waste into gutters, catch basins, or creeks; sanitary sewer overflows reaching storm drains; wash water from commercial operations (restaurants, auto shops) entering storm drains; concrete or mortar washout; sediment-laden runoff from construction sites without proper BMPs; and discharge of pool or spa water containing chlorine or algaecides. Walnut Creek and the Contra Costa Clean Water Program operate an Illicit Discharge Detection and Elimination (IDDE) program including citizen reporting, inspections, and dry-weather sampling. Penalties include administrative citations, cost recovery for cleanup, and referral to the SF Bay Regional Water Quality Control Board for Clean Water Act enforcement with fines up to $10,000 per day per violation under the federal Clean Water Act. Report spills to Walnut Creek Public Works or call 911 for emergencies involving hazardous materials reaching creeks.
Contact your local code enforcement office for specific penalty information.
Walnut Creek, CA
Walnut Creek restricts RV, boat, and trailer parking in residential zones. These vehicles cannot be stored in front yards or on public streets for extended p...
Walnut Creek, CA
Walnut Creek enforces the California Vehicle Code 22651(k) statewide 72-hour street parking limit. Downtown has metered parking and timed zones. Residential ...
Walnut Creek, CA
Walnut Creek restricts overnight parking of commercial vehicles in residential zones. Vehicles with commercial plates exceeding specified weight or length li...
Walnut Creek, CA
Properties in Walnut Creek's Very High Fire Hazard Severity Zone and State Responsibility Area — including the city's eastern hills near Mount Diablo and alo...
Walnut Creek, CA
Walnut Creek is served by East Bay Municipal Utility District (EBMUD) and Contra Costa Water District (CCWD), both of which enforce permanent statewide water...
Walnut Creek, CA
Noxious weeds on the Contra Costa County Agricultural Commissioner's list — including yellow starthistle, artichoke thistle, and various broom species — must...
Side-by-side rule comparisons with other cities in Contra Costa County.
See how other cities in Contra Costa County handle stormwater management.
See how Walnut Creek's stormwater management rules stack up against other locations.
Help us keep this page accurate. If you notice an error or outdated information, let us know.