HOUSE OF REPRESENTATIVES
H.B. NO.
1728
THIRTY-THIRD LEGISLATURE, 2026
H.D. 1
STATE OF HAWAII
S.D. 1
C.D. 1
A BILL FOR AN ACT
RELATING TO RAINWATER CATCHMENT SYSTEMS.
BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF HAWAII:
SECTION 1. The legislature finds that limited water infrastructure is a major barrier to new housing and sustainable land use in the State. Many properties, whether connected or not to county water systems, face restrictions that prevent efficient water use or new development. Rainwater catchment systems offer a low-cost, sustainable way to supplement water supply for potable and nonpotable uses. The legislature further finds that allowing these systems across all zoning types can reduce strain on public infrastructure, support local self-sufficiency, and encourage responsible water management.
Therefore, the purpose of this Act is to:
(1) Require the counties to allow for the installation and operation of rainwater catchment systems for potable and nonpotable uses on all properties; and
(2) Allow the counties to require registration, inspection, or notification of rainwater catchment systems.
SECTION 2. Chapter 46, Hawaii Revised Statutes, is amended by adding a new section to be appropriately designated and to read as follows:
"[Underlined: §46- ] [Underlined: Regulation of rainwater catchment systems.] [Underlined: (a) Pursuant to the authority granted to the counties under section 46][Underlined: -1.5(13) and (14)(A)(ii), each county shall permit the installation and operation of rainwater catchment systems for potable and nonpotable uses on all properties, regardless of whether the property is connected to a county water system.]
[Underlined: (b) Each county may require registration, inspection, or notification of rainwater catchment systems where necessary to protect public health or water quality but shall not unreasonably restrict or prohibit their use.]
[Underlined: (c) As used in this section:]
[Underlined: "County water system" means any public water infrastructure operated or regulated by a department or board of water supply of the county.]
[Underlined: "Rainwater catchment system" means a system designed to collect and store rainwater from rooftops or other surfaces for potable and nonpotable use, including irrigation, toilet flushing, cleaning, and landscape watering.]"
SECTION 3. New statutory material is underscored.
SECTION 4. This Act shall take effect on July 1, 2026.
Report Title:
Counties; Rainwater Catchment Systems
Description:
Requires the counties to allow for the installation and operation of rainwater catchment systems for potable and nonpotable uses on all properties. Allows the counties to require registration, inspection, or notification of rainwater catchment systems. (CD1)
The summary description of legislation appearing on this page is for informational purposes only and is not legislation or evidence of legislative intent.