La Habra, CA Landscaping Rules: Rainwater Harvesting (2026)

La Habra's Water Efficient Landscape Ordinance, codified at Municipal Code Chapter 18.16, normally applies its full water-budget calculations to any new landscape project of five hundred square feet or more, and to any rehabilitated landscape project of two thousand five hundred square feet or more, that requires a building or landscape permit, plan check or design review (§ 18.16.030.A.1-2). Section 18.16.030.A.4 carves out a narrower path for water harvesting: where a project uses treated or untreated graywater, or captures rainwater on site, and that captured supply alone covers one hundred percent of the lot's estimated applied water use, and the lot's landscape area is under two thousand five hundred square feet, the project need only comply with the prescriptive measures of Appendix A of the Guidelines for Implementation of the Water Efficient Landscape Ordinance rather than submit the full landscape documentation package, water budget calculations and certification otherwise required under § 18.16.040.

The Guidelines are adopted by the city and describe the specific procedures, calculations and requirements referenced throughout Chapter 18.16. Projects that qualify still must be reviewed by the community development department as part of the applicable building or landscape permit, but the reduced Appendix A path avoids the maximum applied water allowance (MAWA) calculation, the ET adjustment factor analysis and the licensed-professional certification required for standard landscape documentation packages under §§ 18.16.040 and 18.16.050.