Hawthorne, CA Landscaping Rules: Rainwater Harvesting (2026)

Section 17.89.030(B) sets the general rule that any project with 2,500 square feet or less of aggregate landscape area may comply with either the performance requirements of Chapter 17.89 or the prescriptive measures in Appendix E of the Water Efficient Landscape Guidelines. The same subsection then carves out rainwater and graywater specifically: for projects using treated or untreated graywater, or rainwater captured on site, any lot or parcel within the project that has less than 2,500 square feet of landscape and meets that lot or parcel's entire estimated total water use with treated or untreated graywater or stored, on-site captured rainwater is subject only to Section B.5 of Appendix E, not the rest of the chapter's landscape documentation requirements.

Chapter 17.89 itself was adopted by Ordinance 2140, Section 11, in 2017, and amended by Ordinance 2226, Section 7, in 2021, to implement standards at least as effective as the state's Model Water Efficient Landscape Ordinance under Government Code provisions. Above the 2,500-square-foot threshold, or where rainwater and graywater do not cover the full estimated water use, a project instead needs the complete landscape documentation package described in Section 17.89.060, including project information, total landscape area, and the water budget calculations tied to the maximum applied water allowance.