Aliso Viejo, CA Landscaping Rules: Rainwater Harvesting (2026)

Section 7.30.030 sets who must follow Chapter 7.30. Beginning December 1, 2015, the chapter applies to new construction projects with an aggregate landscaped area of 500 square feet or more that require a building or landscape permit, plan check or design review, and to rehabilitated landscape projects with an aggregate landscape area of 2,500 square feet or more that require the same.

Rainwater capture enters in subsection C. For a new construction or rehabilitated landscape project that uses treated or untreated graywater or rainwater capture on site, any lot or parcel in the project with less than 2,500 square feet of landscaped area that meets its landscape water requirement (estimated total water use) entirely with graywater or stored rainwater capture is subject only to Appendix D, Section 5 of the State Model Water Efficient Landscape Ordinance. It is the only provision in the Aliso Viejo code that uses the term rainwater, so it works as a compliance path inside the landscape rules, not as a stand-alone permit program.

Subsection D separately lets any landscape project of 2,500 square feet or less comply by following Appendix D of the state model ordinance. Subsection E excludes registered local, state or federal historical sites, ecological restoration and mined-land reclamation projects that do not need a permanent irrigation system, existing plant collections at botanical gardens and arboretums open to the public, and cemeteries, with limited exceptions for cemetery projects.

Projects that are covered still file a landscape submittal sheet and landscape documentation package before installation (7.30.040). A licensed landscape professional certifies the design and water use calculations, and compliance is verified through a certificate of completion tied to the certificate of use and occupancy or the permit final. The city's findings in section 7.30.020 record that average rainfall in Orange County is approximately 12 inches per year. The city manager administers and enforces the chapter (7.30.060).