Marin County, CA Water Use Rules: Leak Reporting Duty (2026)
Key Facts
- Repair deadline
- 72 hours after leak is discovered
- Applies in
- Urbanized unincorporated Marin areas
- Enforcing agency
- Marin County Public Works
- Companion rule
- Sprinklers may not overspray target area
- Penalty
- Misdemeanor or infraction, § 23.18.130
- Consequence of delay
- Loses "incidental runoff" exemption
Summary
Marin County Code of Ordinances § 23.18.073 requires every property owner in an urbanized unincorporated area to detect and repair leaks in an irrigation system within seventy-two hours of discovering them, as one of the mandatory best management practices for controlling irrigation runoff into county storm drains.
In all urbanized areas, property owners shall control irrigation systems to prevent excessive irrigation runoff by implementing the following BMPs: A.Detect and repair leaks from the irrigation system within seventy-two hours of discovering the leak; ...
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 2026 Update 1).
Full Breakdown
073, part of the County of Marin Stormwater Runoff Pollution Prevention Ordinance, applies in every urbanized area of unincorporated Marin. 10. Property owners must implement listed best management practices, the first of which is the seventy-two-hour leak rule: detect and repair leaks from the irrigation system within seventy-two hours of discovering the leak. The same section also bars aiming sprinkler heads outside the planned application area and bars irrigating during precipitation events. The seventy-two-hour clock protects the exemption Marin gives to ordinary sprinkler overspray. 030(k) defines incidental runoff narrowly: it excludes water that leaves the intended area because of excessive application, intentional overflow, or negligence.
An unrepaired leak that keeps running past the seventy-two-hour window stops qualifying as "incidental" and becomes an illicit discharge subject to enforcement. 120 where it has reasonable cause to suspect a runoff violation.
Violations & Fines
Failing to repair a leaking irrigation system within seventy-two hours is a violation of Chapter 23.18, chargeable as a misdemeanor under Penal Code § 19 or, at the agency's discretion, as an infraction under Government Code § 25132 (§ 23.18.130); each additional day of runoff is a separate offense. The county may also seek a civil injunction and recover investigation and cleanup costs under § 23.18.140, or abate the runoff as a public nuisance under §§ 23.18.100 and 23.18.110.
Frequently Asked Questions
How long do I have to fix a leaking sprinkler system in unincorporated Marin?
Is a little sprinkler overspray illegal?
Which county department enforces the irrigation leak rule?
Sources & Official References
Other rules in Marin County
California rules heatmap·Compare Marin County to another location·View the California water use rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.