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

Day-to-day outdoor water use in unincorporated Colusa County is mostly shaped by state law and by each property's water source, since most rural homes are on private wells. The county does, however, impose landscape water-efficiency standards through zoning Section 44-3.10 (Ord. No. 765), which applies to new construction and rehabilitated landscapes of 2,500 square feet or more in urban residential, commercial, and industrial zones (and to commercial/industrial projects with landscape area of at least ten percent of floor area). Under Section 44-3.10.020, water-intensive turf 'should be limited to 25 percent of the total landscaped area' and is prohibited on slopes of 25 percent or greater. Section 44-3.10.070 requires water-efficient irrigation systems (drip, bubbler, or mini-spray) with rain or moisture shutoff sensors and check valves, and directs that landscape irrigation be scheduled between 8:00 p.m. and 10:00 a.m. to limit evaporation and high-demand use. Section 44-3.10.080 additionally requires compliance with the state Model Water Efficient Landscape Ordinance (MWELO) under the California Water Conservation in Landscaping Act (Government Code Section 65591 et seq.), with the more restrictive standard controlling. Statewide drought emergency rules from the State Water Resources Control Board, when in effect, apply on top of these provisions.