Carlsbad, CA Landscaping Rules: Rainwater Harvesting (2026)

California enacted the Rainwater Capture Act of 2012 (Water Code Section 10570) after the Legislature found in Section 10571 that impervious surfaces across the state have increased stormwater runoff into flood channels and storm sewers, reducing groundwater recharge while recurring droughts pushed the state toward a statutory objective of a 20 percent cut in urban per capita water use by December 31, 2020. Section 10574 is the operative rule for a Carlsbad property owner: using rainwater collected from a rooftop for onsite reuse does not require a water right permit under Section 1201, removing the single biggest legal barrier to installing a rain barrel or cistern.

Section 10573 supplies the working definitions city and county building officials apply: a rain barrel system is a rainwater capture system that runs without electricity or a water pump and is not tied into a potable water system, while a rainwater capture system is any facility built to capture, retain and store rooftop runoff for later onsite use; rainwater itself is precipitation that has not yet reached an offsite storm drain, flood channel or stream and has not already been put to beneficial use. Section 10572 keeps the exemption narrow: it does not alter or impair anyone's existing water rights, does not let an unlicensed contractor perform work requiring a Professional Engineers Act license, does not affect rainwater use on agricultural land, and does not strip the California Building Standards Commission of its authority to set building standards for these systems or a water supplier's authority under Title 17 of the California Code of Regulations.

A Carlsbad homeowner still needs whatever plumbing or building permit the City's own building code requires for physical installation; the Act removes only the water-rights permit layer.