Tustin, CA Landscaping Rules: Rainwater Harvesting (2026)

Tustin City Code Section 9702a4, part of the Water Efficient Landscapes chapter, provides that for new or rehabilitated projects using treated or untreated graywater or rainwater capture on site, any lot or parcel within a project that has less than 2,500 square feet of landscaped area and meets the lot or parcel's landscape water requirement, called the Estimated Total Water Use, entirely with treated or untreated graywater or through stored rainwater capture on site is subject only to Appendix A of the Guidelines. That is a meaningful carve-out because Section 9702a1 and a2 otherwise require a full Landscape Documentation Package, water use calculations against the Maximum Applied Water Allowance, and a licensed professional's certification for any new construction project of 500 square feet or more or any rehabilitated project of 2,500 square feet or more.

A qualifying small lot that captures its own rainwater instead files under the streamlined prescriptive path in Appendix A of the City's Guidelines for Implementation of the Water Efficient Landscape Ordinance, adopted under Section 9701 to implement state water-efficiency law. The Landscape Documentation Package generally required under Section 9703a must still be submitted to the Community Development Department for any project that does not qualify for this exception, and it must bear the certification of a licensed landscape architect or contractor under Section 9703b. Irrigation of all landscaped areas, including those built around rainwater capture, remains subject to the local water purveyor's conservation rules and water-waste penalties under Section 9704b.