San Mateo, CA Landscaping Rules: Water Restrictions (2026)
Water restrictions in San Mateo, CA, also called the watering schedule, outdoor irrigation rules, or drought ordinance, set which days and hours you can run sprinklers or irrigation.
Key Facts
- Water Provider
- Cal Water (San Mateo District)
- No Watering Hours
- 10 AM – 5 PM (summer)
- Rain Rule
- No watering within 48 hours of rain
- Runoff
- Prohibited
- Code
- SMMC Ch. 23.72
Summary
San Mateo's water is provided by Cal Water (San Mateo District). Water conservation ordinances (SMMC Ch. 23.72) apply to landscaping. Year-round prohibitions include runoff, watering during/after rain, and midday irrigation.
Model Water Efficient Landscape Ordinance (MWELO). The MWELO is also referenced by Title 24, Part 11, Chapters 4 and 5 CalGreen Building Code. All local agencies must adopt, implement, and enforce the MWELO or a local Water Efficient Landscape Ordinance (WELO) that is at least as effective as the MWELO. Usually, local agencies that adopt WELOs create a more stringent ordinance than MWELO. The purpose of water efficient landscape ordinances is to not only increase water efficiency but to improve environmental conditions in the built environment. Local agencies are required to report on implementation annually by January 31 of each year to DWR's Water Use Efficiency Branch using the WUEdata Portal.
Official source re-checked September 8, 2026: the cited page had not changed since it was quoted.
Full Breakdown
City of San Mateo water is supplied by California Water Service (Cal Water). SMMC Chapter 23.72 (Water Conservation in Landscaping) regulates irrigation and water use in new and renovated landscapes. Year-round state-mandated restrictions include: no irrigation causing runoff onto streets or sidewalks, no irrigation within 48 hours of measurable rain, and no irrigation between 10 AM and 5 PM during summer. Swimming pools are classified as high-water-use features under the landscaping ordinance. Cal Water may impose additional restrictions during drought conditions. Check calwater.com for current San Mateo District restrictions.
Frequently Asked Questions
What are the lawn watering restrictions in San Mateo?
Are there drought watering rules in San Mateo?
Sources & Official References
Other rules in San Mateo
How San Mateo compares: Cities with the Strictest Water Restrictions·California rules heatmap·Compare San Mateo to another location·View the California landscaping rules overview
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Water Restrictions in Nearby Cities
How other cities in San Mateo County handle water restrictions.