Sunnyvale, CA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- State law
- AB 1750 Rainwater Capture Act
- Small barrels
- Under 50 gallons no permit
- Large cistern
- Permit over 5000 gallons
- Allowed use
- Irrigation and non-potable
- Rebates
- Valley Water program
Summary
Rainwater collection is legal in Sunnyvale under California AB 1750. Rain barrels under 50 gallons are exempt from permits. Larger cistern systems require plumbing permits for potable or irrigation use.
AB 1750, Solorio. Rainwater Capture Act of 2012. (1) Under existing law, the State Water Resources Control Board (state board) and the California regional water quality control boards prescribe waste discharge requirements for the discharge of stormwater in accordance with the national pollutant discharge elimination system (NPDES) permit program and the Porter-Cologne Water Quality Control Act. Under existing law, the state board administers a water rights program pursuant to which the state board grants permits and licenses to appropriate water, upon an application to appropriate water. This bill would enact the Rainwater Capture Act of 2012, which would provide that use of rainwater collected from rooftops does not require a water right permit from the state board.
Full Breakdown
California AB 1750, the Rainwater Capture Act of 2012, authorizes property owners to collect and use rainwater from rooftops for non-potable purposes such as landscape irrigation, toilet flushing, and washing. Sunnyvale follows this state framework and generally allows rain barrels up to about 50 gallons without a permit when installed on stable ground, screened to prevent mosquito breeding, and overflow directed away from foundations. Larger cisterns over 5000 gallons or systems integrated with household plumbing require a plumbing permit through the Sunnyvale Building Safety Division. Rainwater cannot be used for drinking unless treated to potable standards. Valley Water offers rebates through the Rain Barrel and Cistern Rebate Program for qualified installations.
Frequently Asked Questions
Can I drink harvested rainwater?
Do I need to screen my rain barrel?
Sources & Official References
Other rules in Sunnyvale
California rules heatmap·Compare Sunnyvale to another location·View the California landscaping rules overview
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Rainwater Harvesting in Nearby Cities
How other cities in Santa Clara County handle rainwater harvesting.