Riverside, CA Landscaping Rules: Native Plants (2026)

Riverside Municipal Code (RMC) Chapter 19.570 — Water Efficient Landscaping & Irrigation — is the City's implementation of California's Model Water Efficient Landscape Ordinance (MWELO; 23 CCR §490 et seq.) under Cal. Water Code §65595. The ordinance applies to: (1) new construction landscape projects ≥500 sq ft requiring a building or landscape permit; (2) rehabilitated landscape projects ≥2,500 sq ft; and (3) any cemetery or developer-installed landscape with the same thresholds. Each project must demonstrate compliance through a Landscape Documentation Package: a water-budget calculation showing Estimated Total Water Use (ETWU) ≤ Maximum Applied Water Allowance (MAWA), with MAWA calculated using ETo × 0.55 (residential) or 0.45 (non-residential) of reference evapotranspiration. Because turf has a high plant factor (0.6-0.8) under MWELO, meeting the budget effectively requires the majority of the planting area to be low-water (plant factor 0-0.3) — a strong functional preference for California natives and drought-tolerant Mediterranean species. RMC 19.570 also incorporates MWELO's soil-management plan (compost added at 4 cubic yards per 1,000 sq ft), hydrozoning (grouping plants by water need), and dedicated irrigation meter requirement for non-residential landscapes >5,000 sq ft. Section 19.570.080 covers exceptions, including registered local-historic / cultural-heritage landscapes. California's AB 1572 (Water Code §115922, signed October 2023) layers on a phased ban on irrigating non-functional turf with potable water — public agency property from Jan 1, 2027; commercial/industrial/institutional Jan 1, 2028; HOA common areas Jan 1, 2029. AB 1572 does NOT apply to single-family residential landscapes.