Costa Mesa, CA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- State Law
- AB 1750 Rainwater Capture Act
- No Permit Needed
- Systems under 5,000 gallons
- Use
- Irrigation and non-potable only
- Mosquito Prevention
- Containers must be covered
- Rebates
- Check Mesa Water District
Summary
California law encourages rainwater harvesting, and Costa Mesa permits residents to collect and store rainwater for irrigation and non-potable uses without a permit for systems under 5,000 gallons. Rebates may be available through Mesa Water District.
10573. Solely for the purposes of this part, and unless the context otherwise requires, the following definitions govern the construction of this part:
(a) “Developed or developing lands” means lands that have one or more of the characteristics described in subparagraphs (A) to (C), inclusive, of paragraph (4) of subdivision (b) of Section 56375.3 of the Government Code.
(b) “Rain barrel system” is a type of rainwater capture system that does not use electricity or a water pump and is not connected to or reliant on a potable water system.
(c) “Rainwater” means precipitation on any public or private parcel that has not entered an offsite storm drain system or channel, a flood control channel, or any other stream channel, and has not previously been put to beneficial use.
(d) “Rainwater capture system” means a facility designed to capture, retain, and store rainwater flowing off a building rooftop for subsequent onsite use.
(e) “Stormwater” means temporary surface water runoff and drainage generated by immediately preceding storms. This definition shall be interpreted consistent with the definition of “stormwater” in Section 122.26 of Title 40 of the Code of Federal Regulations. 10574. Use of rainwater collected from rooftops does not require a water right permit pursuant to Section 1201.
Full Breakdown
California Rainwater Capture Act of 2012 (AB 1750) allows residential rainwater harvesting statewide without a permit for rooftop collection systems. Costa Mesa residents may install rain barrels and cisterns for irrigation and non-potable outdoor use. Systems under 5,000 gallons generally do not require permits. Larger systems may need a building permit for structural support. Stored water must not create standing water conditions that breed mosquitoes: containers should be covered and screened. The Mesa Water District and Orange County Water District may offer rebates for rain barrel purchases. Costa Mesa also supports low-impact development practices including rain gardens, bioswales, and permeable paving through its stormwater management program. Rainwater should not be used for drinking water without proper treatment. Development Services at (714) 754-5245 handles permits for larger systems.
Violations & Fines
Rainwater harvesting is legal and encouraged. However, systems creating mosquito breeding habitat or structural hazards may receive health or code enforcement notices. Large unpermitted systems may need retrofit.
Frequently Asked Questions
Is it legal to collect rainwater in Costa Mesa?
Are there rebates for rain barrels in Costa Mesa?
Can I drink collected rainwater in Costa Mesa?
Sources & Official References
Other rules in Costa Mesa
California rules heatmap·Compare Costa Mesa to another location·View the California landscaping rules overview
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Rainwater Harvesting in Nearby Cities
How other cities in Orange County handle rainwater harvesting.