Ontario, CA Landscaping Rules: Water Restrictions (2026)

Ontario's water-conservation rules are codified at Ontario Municipal Code Chapter 8A (Water Conservation Plan), sections 6-8.20 through 6-8.35. The plan is tiered: a baseline Voluntary Conservation Stage (section 6-8.25) plus six mandatory shortage stages (sections 6-8.26 through 6-8.31) that the City Council may invoke when supply is reduced from ten percent up to more than fifty percent. As of this writing the City is in the Voluntary Stage with no drought declared, so the WaterWise conservation measures are requests rather than enforceable mandates. Under section 6-8.21 the City declares that 'the waste or unreasonable use, or unreasonable method of use of water be prevented,' and section 6-8.23 permanently bars certain new water connections from using non-recycling decorative fountains, single-pass cooling systems, and non-reuse car-wash or laundry systems. The City Council may declare a higher stage under section 6-8.22 based on determinations by the Metropolitan Water District of Southern California, the Inland Empire Utilities Agency, a Governor's executive order, or a state-agency restriction; once declared, restrictions take effect immediately upon publication in a newspaper of general circulation. Ontario Municipal Utilities Company administers the program through the WaterWise initiative.