Rainwater Harvesting: Daly City vs San Mateo
How do rainwater harvesting rules compare between Daly City, CA and San Mateo, CA?
Daly City and San Mateo have similar restriction levels.
Daly City, CA
San Mateo County
Rainwater harvesting on residential property is broadly permitted under California's Rainwater Capture Act of 2012 (Cal. Water Code Sec. 10574), which allows property owners to install and operate rainwater catchment systems from their own rooftops without an appropriative water-rights permit from the State Water Board. Daly City has no separate prohibition. Rain barrels (under 360 gallons / 50 inches high) typically do not require a building permit; larger cisterns must meet California Plumbing Code (Title 24, Part 5, Chapter 17) for non-potable on-site water reuse.
View full Daly City rules →San Mateo, CA
San Mateo County
Rainwater harvesting is legal and encouraged in San Mateo under California AB 1750. Rain barrels under 5,000 gallons are exempt from building permits. Cal Water may offer rebates. Collected rainwater can be used for irrigation and non-potable purposes.
View full San Mateo rules →Key Facts Comparison
| Fact | Daly City | San Mateo |
|---|---|---|
| State authority | Cal. Water Code Sec. 10574 | - |
| BAWSCA rebate | Up to $200 / select rain barrels | - |
| Permit threshold | Cisterns >360 gal need plumbing review | - |
| Indoor reuse | Cal. Plumbing Code Ch. 17 | - |
| Legal Status | - | Legal — AB 1750 |
| Permit Exempt | - | Under 5,000 gallons |
| Approved Uses | - | Irrigation, non-potable |
| Water Provider | - | Cal Water Service |
| Vector Control | - | SM County |
Highlighted rows indicate differences between cities.
Daly City FAQ
Do I need a permit for a rain barrel in Daly City?
No. Residential rain barrels under approximately 360 gallons and connected only for outdoor irrigation are exempt from building permits under California's standard approach; the Rainwater Capture Act allows on-site rooftop capture without water-rights paperwork.
Can I get a rebate?
Yes - BAWSCA offers up to a $200 rebate on qualifying rain barrels for Daly City water customers.
Can I plumb a cistern to flush my toilets?
Yes, but the installation must comply with California Plumbing Code Chapter 17 (non-potable rainwater catchment systems) and requires a plumbing permit and backflow protection.
San Mateo FAQ
Can I collect rainwater in San Mateo?
Yes. AB 1750 allows residential rainwater collection. Rain barrels under 5,000 gallons are exempt from permits.
Are there rebates for rain barrels?
Cal Water Service periodically offers rebates. Check their website for current program availability.
Can I drink collected rainwater?
No. Collected rainwater is approved for non-potable uses only. Treatment would be required for potable use.
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