Rain and storageGuide
Are rain barrels legal in California?
Yes. State law says you do not need a water right permit to use rainwater collected from a rooftop. Local building rules can still apply.
Listen to this article
Read aloud by an AI voice.
What the law says
The Rainwater Capture Act of 2012 (AB 1750) added Water Code sections 10570 to 10574.
- Section 10574: use of rainwater collected from rooftops does not require a water right permit.
- Section 10573: a rain barrel system is a rainwater capture system that uses no electricity and no pump, and is not connected to or reliant on a potable water system.
- Section 10572: the act does not change existing water rights law, and it does not limit the state's authority to set building standards for rainwater systems.
What it does not say
The act does not set a barrel size limit. It does not say a city or county can never ask for a permit on a larger tank or one tied into your plumbing.
If you plan more than a simple barrel under a downspout, call your city or county building department first. In unincorporated Sonoma County that is Permit Sonoma, (707) 565-1900.
Keep it simple and safe
- Use the water outside. The law is about nonpotable use. Do not drink it.
- Keep the barrel closed and screened so mosquitoes cannot get in.
- Do not connect it to your drinking water pipes.
- Send the overflow away from your foundation.
Next: how many gallons your roof can catch, and what size tank holds it.
The mosquito, drinking and overflow points are common sense advice from The Downspout, not from the statute.
Sources
- AB 1750, Rainwater Capture Act of 2012, enrolled text
- Permit Sonoma phone from Sonoma Water graywater page
Checked 2026-10-11. Rules and programs change. If something here is out of date, the source above wins. Spot an error? See our corrections policy.
Related reads
Rain and storageRain catch calculator for your roofA 1,000 square foot roof catches about 15,700 gallons in an average Santa Rosa year. Enter your ZIP and roof size to see yours.Updated Oct 11, 2026
Rain and storageHow much rain Sonoma County getsSanta Rosa averages 31.5 inches a year. Petaluma gets 25.6. Healdsburg gets 42.8. Most of it falls from November to March.Updated Oct 11, 2026
Rain and storageWater storage tank size calculatorAnswer a few questions about your household, animals and garden. The calculator works out your daily use, then the tank size for the days you want to cover, and whether one tank or several fits.Updated Oct 11, 2026