National City, CA Landscaping Rules: Water Restrictions (2026)

Section 18.44.190 of the Land Use Code (Title 18) is National City's water efficient landscape regulation, written to carry out California state law. It sets a time window rather than assigned days of the week: the irrigation schedule for a covered project provides that overhead irrigation will be scheduled between four p.m. and nine a.m., unless weather conditions prevent it, and running the system outside that window is allowed for auditing and system maintenance.

Coverage depends on project size. New industrial, commercial, institutional or multi-family development with less than two thousand five hundred square feet of landscaped area, and new single-family and two-family homes with less than five thousand square feet, must install on-site landscaping and a below grade automatic irrigation system. The fuller water budget rules apply, when a building permit or discretionary permit is required, to projects at or above those sizes, to model homes, to public agency projects, and to rehabilitated landscapes of two thousand five hundred square feet or more at existing nonresidential and multi-family sites. Registered historical sites, ecological restoration, mined land reclamation, botanical gardens and arboreta, and single-family homes rebuilt after a natural disaster are exempt.

A covered project faces a hard water cap. Total annual applied water must be less than or equal to the maximum applied water allowance (MAWA), and the section prints the MAWA formula using reference evapotranspiration, landscaped area and special landscaped area. Irrigation must be regulated by an automatic controller using evapotranspiration or soil moisture sensor data, with a manual shutoff valve as close as possible to the water supply. Only low volume irrigation is used within twenty-four inches of an impermeable surface unless that surface drains entirely into a landscaped area, and slopes steeper than twenty-five percent are irrigated at seventy-five hundredths inches per hour or less. Tertiary treated recycled water is required when the water purveyor has it available.

After approval, the owner operates the system consistent with the MAWA, replaces broken components with equal or better parts, and files a certificate of completion within ten days after installation. The development services director administers the section. Subsection T is written for any person: no irrigation that results in runoff, low head drainage or overspray.