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San Luis Obispo County, CA Environmental Rules: Stormwater Management (2026)

Heavy Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Core rule
Non-stormwater discharge into storm drains banned
Adopted by
Ordinance No. 3143 (2008)
Misdemeanor fine
Up to $1,000 and/or 6 months in jail
Infraction fine
$100/$200/$500 for repeat offenses in a year
Continuing violation
Each day counted as a separate offense
Also enforceable by
District attorney civil action (§ 8.68.210)

Summary

Section 8.68.080 of the County Code bans any non-stormwater discharge into San Luis Obispo County's storm drain system, with narrow exceptions for permitted NPDES discharges, firefighting flows, certain agricultural discharges, and incidental flows like landscape irrigation runoff and car-washing. Violations default to a misdemeanor and can be prosecuted as a continuing daily nuisance.

These county ordinances apply to unincorporated areas of San Luis Obispo County. Incorporated cities within the county may have their own rules that take precedence over county-level regulations.

Non-stormwater discharges to the county storm drain system are prohibited. (1)Exceptions to Discharge Prohibition. The following discharges are exempt from the prohibition set forth above:a.Any discharge regulated under a National Pollutant Discharge Elimination System (NPDES) permit issued to the discharger and administered by the State of California under authority of the United States Environmental Protection Agency, provided that the discharger is in full compliance with all requirements of the permit and other applicable laws or regulations ... e.Incidental noncommercial and nonindustrial discharges resulting from water line flushing, landscape irrigation, diverted stream flows, rising groundwaters, uncontaminated groundwater infiltration, uncontaminated pumped groundwater, discharges from potable water sources, foundation drains, air conditioning condensation, springs, water from crawl space pumps, car washing, and flows from riparian habitats and wetlands.

Full Breakdown

68, the county's Stormwater Pollution Prevention and Discharge Control ordinance adopted by Ordinance No. 080's blanket rule: non-stormwater discharges to the county storm drain system are prohibited. Five categories are carved out as exceptions: discharges under a state-administered NPDES permit; discharges under the county's own storm drain discharge permit issued under Article III; firefighting flows; certain agricultural discharges regulated by the State or Regional Water Quality Control Board; and incidental, noncommercial flows such as water-line flushing, landscape irrigation, rising groundwater, air-conditioning condensation, and car washing.

090 separately bans any discharge that would violate the county's own NPDES Permit No. 100 bans illicit connections to the storm drain system outright, retroactively reaching connections made before the ordinance existed. 110 layers on affirmative duties: no littering into any street, storm drain, catch basin or drainage structure, and property owners along a paved sidewalk must keep it swept clear of dirt and litter rather than sweeping debris into the gutter. 150 makes any violation of the chapter a misdemeanor by default, though the county can charge it as an infraction instead.

160 sets the misdemeanor fine at up to $1,000 and up to six months in county jail, or both, while an infraction runs $100 for a first offense, $200 for a second within a year, and $500 for each further offense. 200 declares any violating condition a public nuisance the county can abate at the property owner's cost, with the cleanup bill becoming a lien against the property.

Violations & Fines

A violation of Chapter 8.68 defaults to a misdemeanor under Section 8.68.150, punishable under Section 8.68.160 by up to a $1,000 fine, six months in county jail, or both; the county can instead charge it as an infraction ($100/$200/$500 for repeat offenses). Section 8.68.170 makes each day of continued violation a separate offense, and Section 8.68.210 lets the district attorney also pursue an injunction and cost recovery through civil action.

Frequently Asked Questions

Can I wash my car in the driveway in San Luis Obispo County?
Yes, car washing is one of the incidental discharges Section 8.68.080(1)(e) exempts from the storm drain discharge ban, along with things like landscape irrigation runoff and air-conditioning condensation. What is not exempt is anything that would violate the county's NPDES permit under Section 8.68.090.
What is the penalty for an illegal storm drain discharge in the county?
Section 8.68.150 makes it a misdemeanor by default, punishable under Section 8.68.160 by up to a $1,000 fine and six months in county jail, though the county has discretion to charge it as a lesser infraction instead, with fines of $100 to $500 depending on how many times it recurs in a year.
Does a stormwater violation count as a new offense every day it continues?
Yes. Section 8.68.170 makes a person, firm or organization guilty of a separate offense for every day, or portion of a day, that a Chapter 8.68 violation is committed, continued or permitted, and it is punished accordingly for each of those days.

Sources & Official References

Other rules in San Luis Obispo County

All San Luis Obispo County rules

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