Water Use Rules in San Mateo County, CA (2026)

1 county-level rule, plus city-specific rules for 1 city in San Mateo County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of San Mateo County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Recycled Water Rules

San Mateo County Ordinance Code Section 4.72.140 requires every recycled water or graywater system to be designed and installed in accordance with California law and the local Plumbing Code. The rule sits inside the county's Cross-Connection Control chapter, run by the Environmental Health Services Division of San Mateo County Health, which can fine violators and cut off water service.

San Mateo County Recycled & Graywater Rules

Some Restrictions

San Mateo County Ordinance Code § 4.72.140

4.72.140 - Recycled or graywater systems. All components of recycled or graywater systems must be designed and installed in accordance with California law and local Plumbing Codes.

Full ordinance details →Official source ↗

Water Use Rules by City in San Mateo County

1 cities in San Mateo County have their own water use rules rules. Each link goes to that city's dedicated page with code citations.

Redwood CityPop. 84,518

1 verified rule • Recycled Water Rules

All San Mateo County ordinances

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San Mateo County Ordinance Hub →