Santa Monica, CA Environmental Rules: Stormwater Management (2026)
Key Facts
- Prohibited
- Non-stormwater discharges to MS4 without Director written approval
- Advance notice
- 72 hours before any allowed conditional non-stormwater discharge
- Trash receptacles
- Must have solid covers, closed at all times except during disposal
- Pressure washing limit
- 0.006 gallons per sq ft maximum
- Development requirement
- Runoff Mitigation Plan required before building permit issuance
- Design storm
- 0.75-inch, 24-hour storm event (SWQDv)
Summary
Santa Monica prohibits non-stormwater discharges to the city's storm sewer system (MS4) and requires all property owners and businesses to follow good housekeeping practices including keeping trash receptacles covered and closed. Development projects must submit a Runoff Mitigation Plan before receiving a building permit.
§ 7.10.040. General prohibitions. (a) Except as otherwise provided in Section 7.10.050, it is unlawful for any person to discharge or cause a non-stormwater discharge to the MS4. (b) It is unlawful for any person to discharge or cause, either individually or jointly, a discharge into or from the MS4 that results in or contributes to a violation of the permit. (c) It is unlawful for any person to discharge or cause a discharge that results in or contributes to a condition of public nuisance.
§ 7.10.080. Good housekeeping requirements. (b) Trash Containment. Any person undertaking any activity or use of a premises that may cause or contribute to stormwater pollution or contamination, illicit discharges, or non-stormwater discharges to the MS4 shall ensure that outdoor containers and trash receptacles are covered, leak-free and protected. Without limiting the generality of the foregoing, trash receptacles shall have solid covers and shall be closed at all times other than during trash disposal to prevent the entry of rain and animals, and the generation of fugitive trash or debris by runoff, wind or animal activity.
Full Breakdown
Discharging anything other than stormwater to the municipal storm drain system is unlawful without prior written Director approval, obtained at least 72 hours in advance. All premises must keep outdoor trash receptacles covered with solid lids at all times except during disposal. Machinery repairs in uncovered outdoor areas must be performed on absorbent material. Pressure washing of hard surfaces is limited to 0.006 gallons per square foot. Any development project must submit and have approved a Runoff Mitigation Plan demonstrating how it will manage the stormwater quality design volume (0.75-inch, 24-hour storm event) through Low Impact Development measures or pay a Runoff Reduction Fee.
Violations & Fines
Criminal penalty: up to $500 fine or up to 6 months in county jail, or both. Administrative fines also available under Chapters 1.09 and 1.10. Civil action by any person including the City is available.
Frequently Asked Questions
Can I wash my driveway water into the storm drain?
What stormwater requirements apply when I build or add on?
Can my swimming pool drain to the storm drain?
Sources & Official References
Other rules in Santa Monica
California rules heatmap·Compare Santa Monica to another location·View the California environmental rules overview
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Stormwater Management in Nearby Cities
How other cities in Los Angeles County handle stormwater management.