Marin County, CA Water Use Rules: Recycled Water Rules (2026)
Key Facts
- Pond may discharge only during
- 25-year, 24-hour storm event
- Report deadline
- 24 hours after any release
- Report to
- Regional Water Board and Marin County
- Enforcing agency
- Marin County Public Works
- Governing section
- § 23.18.073(D)
- Companion exemption
- Ch. 23.10 reclaimed-water landscapes
Summary
Marin County Code of Ordinances § 23.18.073(D) lets property owners irrigate with recycled water, but any holding pond built for it may not discharge except during a twenty-five-year, twenty-four-hour storm event, and any release must be reported to the Regional Water Board and the county within twenty-four hours.
In all urbanized areas, property owners shall control irrigation systems to prevent excessive irrigation runoff by implementing the following BMPs: ...D.Where recycled water is used for irrigation, design and manage holding ponds such that no discharge occurs unless it is the result of the twenty-five-year-twenty-four-hour storm event. Any releases from holding ponds must be reported to the regional water board and the county within twenty-four hours of the discharge.
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(D), part of the County of Marin Stormwater Runoff Pollution Prevention Ordinance's irrigation-runoff controls, is the county's specific rule for sites that irrigate with recycled water. It requires that any holding pond built to manage that recycled water be designed and managed so that it does not discharge except as the result of a twenty-five-year, twenty-four-hour storm event, meaning the statistically rare storm that has roughly a four percent chance of occurring in a given year. If a holding pond does release water outside that narrow allowance, the owner or operator must report the release to both the applicable California Regional Water Quality Control Board and Marin County within twenty-four hours of the discharge. 060. 120 and can order sampling or monitoring at the owner's expense if it suspects an unreported release.
Violations & Fines
An unreported or out-of-storm release from a recycled-water holding pond violates Chapter 23.18 and is chargeable as a misdemeanor under Penal Code § 19, or as an infraction under Government Code § 25132 at the agency's discretion, with each day of noncompliance a separate offense (§ 23.18.130). The county may also sue for an injunction and cost recovery under § 23.18.140, or declare the condition a public nuisance and abate it, placing a lien on the property for the cost under §§ 23.18.100 and 23.18.110.
Frequently Asked Questions
Can I use recycled water for irrigation in unincorporated Marin?
What do I do if my recycled-water pond overflows?
Does using reclaimed water get my landscape out of the county's water-efficiency rules?
Sources & Official References
Other rules in Marin County
California rules heatmap·Compare Marin County to another location·View the California water use rules overview
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