Minnesota Rainwater Catchment Systems Need Commissioner Approval

Minnesota's plumbing code, Minnesota Rules part 4714.1602 (amending Uniform Plumbing Code section 1602.1), governs rainwater catchment systems. Any system that collects and pipes rainwater for nonpotable uses, water closets, urinals, industrial processes, water features, vehicle washing, cooling tower makeup, and similar uses such as landscape irrigation, must be approved by the commissioner of Labor and Industry. These systems require a permit and licensed installation, must have no direct cross-connection to a potable water supply, and use air-gap or backflow-preventer protection on any makeup connection. A simple rain barrel that gravity-feeds a garden falls outside the plumbing-permit trigger.

Installing a plumbed rainwater catchment system without commissioner approval, a permit, or licensed installation violates the state plumbing code, exposing the owner to correction orders, permit revocation, and enforcement by the Department of Labor and Industry.