Napa County, CA Landscaping Rules: Water Restrictions (2026)

Chapter 18.118 of Title 18 (Zoning) requires water-efficient landscape design for projects that involve new or rehabilitated landscaping reviewed by the Conservation, Development and Planning Department. The WELO applies to any project that (a) requires a county building permit, (b) includes new or rehabilitated landscaping as part of the building plans or conditions of approval, and either (c) is a public agency, private development, or developer-installed project with at least 2,500 square feet of landscape area, or (d) is a homeowner-provided or homeowner-hired project with at least 5,000 square feet of landscape area. New or rehabilitated cemeteries have special conditions. Exempt projects include registered local, state, or federal historical sites, ecological restoration projects that do not require a permanent irrigation system, mined-land reclamation projects that do not require a permanent irrigation system, and plant collections that are part of botanical gardens and arboretums open to the public. Qualifying projects must submit a Landscape Documentation Package containing a Landscape Design Plan, Irrigation Design Plan, Grading Design Plan, Soil Management Report, Water Efficient Landscape Worksheets demonstrating Maximum Applied Water Allowance (MAWA) and Estimated Total Water Use (ETWU), Certificate of Completion, Certificate of Installation, Irrigation Scheduling, and a Landscape and Irrigation Maintenance Schedule. State law (California Code of Regulations Title 23, Division 2, Chapter 2.7) provides the underlying MWELO standards that the county WELO must meet or exceed.