HI HB1728

Requires all Hawaii counties to permit installation and operation of rainwater catchment systems for both potable and non-potable uses on all properties, regardless of connection to county water systems.

Counties must adopt rules or ordinances establishing safety, maintenance, design, and backflow prevention standards to prevent contamination of public, county, or private water sources.

Counties may require registration, inspection, or notification of rainwater catchment systems to protect public health or water quality, but cannot unreasonably restrict or prohibit their use.

Defines rainwater catchment systems as those collecting and storing rainwater from rooftops or surfaces for uses including irrigation, toilet flushing, cleaning, and landscape watering.

Effective date set for July 1, 3000 (placeholder date indicating future implementation pending amendment).