HB1728 • 2026

RELATING TO RAINWATER CATCHMENT SYSTEMS.

Passed Legislature

This bill passed both chambers and reached final enrollment, even if later executive action is not shown here.

Sponsor: EVSLIN, AMATO, BELATTI, GARRETT, GRANDINETTI, ILAGAN, KEOHOKAPU-LEE LOY, KILA, KUSCH, MARTEN, MIYAKE, MORIKAWA, PERRUSO, POEPOE, REYES ODA, SHIMIZU, SOUZA, TAKAYAMA, TARNAS, Matayoshi
Last action: 2026-05-07
Official status: Transmitted to Governor.
Effective date: Not listed

Plain English Breakdown

Using official source text because the generated explanation was unavailable or could not be confirmed against the official bill text.

RELATING TO RAINWATER CATCHMENT SYSTEMS.

What This Bill Does

RELATING TO RAINWATER CATCHMENT SYSTEMS.
Counties; Rainwater Catchment Systems 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)

Limits and Unknowns

This entry is temporarily using official source text because the generated explanation could not be confirmed against the official bill text during the last sync.

Amendments

These notes stay tied to the official amendment files and metadata from the legislature.

CD1

Hawaii published version CD1

Plain English: HB1728 CD1 HOUSE OF REPRESENTATIVES H.B.

HB1728 CD1 HOUSE OF REPRESENTATIVES H.B.
NO.
1728 THIRTY-THIRD LEGISLATURE, 2026 H.D.
1 STATE OF HAWAII S.D.

HD1

Hawaii published version HD1

Plain English: HB1728 HD1 HOUSE OF REPRESENTATIVES H.B.

HB1728 HD1 HOUSE OF REPRESENTATIVES H.B.
NO.
1728 THIRTY-THIRD LEGISLATURE, 2026 H.D.
1 STATE OF HAWAII A BILL FOR AN ACT RELATING TO RAINWATER CATCHMENT SYSTEMS .

SD1

Hawaii published version SD1

Plain English: HB1728 SD1 HOUSE OF REPRESENTATIVES H.B.

HB1728 SD1 HOUSE OF REPRESENTATIVES H.B.
NO.
1728 THIRTY-THIRD LEGISLATURE, 2026 H.D.
1 STATE OF HAWAII S.D.

Bill History

2026-05-08 S
Received notice of passage on Final Reading in House (Hse. Com. No. 888).
2026-05-07 H
Transmitted to Governor.
2026-05-06 H
Received notice of Final Reading (Sen. Com. No. 816).
2026-05-06 H
Passed Final Reading as amended in CD 1 with none voting aye with reservations; none voting no (0) and none excused (0).
2026-05-06 S
Passed Final Reading, as amended (CD 1). Ayes, 25; Aye(s) with reservations: none . 0 No(es): none. 0 Excused: none.
2026-04-29 S
48 Hrs. Notice (as amended CD 1) 05-06-26
2026-04-29 S
Reported from Conference Committee as amended CD 1 (Conf. Com. Rep. No. 84-26).
2026-04-29 H
Forty-eight (48) hours notice Wednesday 05-06-26.
2026-04-29 H
Reported from Conference Committee (Conf Com. Rep. No. 84-26) as amended in (CD 1).
2026-04-29 H
The Conference Committee recommends that the measure be Passed, with Amendments. The votes were as follows: 3 Ayes: Representative(s) Hashem, Tarnas, Souza; Ayes with reservations: none; 0 Noes: none; and 0 Excused: none.
2026-04-29 S
The Conference committee recommends that the measure be PASSED, WITH AMENDMENTS. The votes of the Senate Conference Managers were as follows: 3 Aye(s): Senator(s) Wakai, San Buenaventura, Fevella; Aye(s) with reservations: none ; 0 No(es): none; and 1 Excused: Senator(s) Lee, C..
2026-04-27 S
Conference committee meeting scheduled for 04-29-26 10:50AM; Conference Room 325.
2026-04-20 H
Received notice of Senate conferees (Sen. Com. No. 713).
2026-04-20 S
Senate Conferees Appointed: Wakai Chair; Lee, C., San Buenaventura Co-Chairs; Fevella.
2026-04-20 S
Received notice of appointment of House conferees (Hse. Com. No. 786).
2026-04-20 H
House Conferees Appointed: Hashem, Tarnas Co-Chairs; Souza.
2026-04-17 S
Received notice of disagreement (Hse. Com. No. 780).
2026-04-16 H
House disagrees with Senate amendment (s).
2026-04-14 H
Returned from Senate (Sen. Com. No. 614) in amended form (SD 1).
2026-04-14 S
Report adopted; Passed Third Reading. Ayes, 25; Aye(s) with reservations: none . Noes, 0 (none). Excused, 0 (none). Transmitted to House.
2026-04-10 S
One Day Notice 04-14-26.
2026-04-10 S
Reported from JDC (Stand. Com. Rep. No. 3748) with recommendation of passage on Third Reading.
2026-04-07 S
The committee(s) on JDC recommend(s) that the measure be PASSED, UNAMENDED. The votes in JDC were as follows: 4 Aye(s): Senator(s) Rhoads, Gabbard, Chang, San Buenaventura; Aye(s) with reservations: none ; 0 No(es): none; and 1 Excused: Senator(s) Awa.
2026-04-01 S
The committee(s) on JDC will hold a public decision making on 04-07-26 10:15AM; Conference Room 016 & Videoconference.
2026-03-30 S
Report adopted; Passed Second Reading, as amended (SD 1) and referred to JDC.
2026-03-30 S
Reported from EIG/WLA (Stand. Com. Rep. No. 3258) with recommendation of passage on Second Reading, as amended (SD 1) and referral to JDC.
2026-03-19 S
The committee(s) on EIG recommend(s) that the measure be PASSED, WITH AMENDMENTS. The votes in EIG were as follows: 5 Aye(s): Senator(s) Wakai, Chang, DeCoite, Richards, Fevella; Aye(s) with reservations: none ; 0 No(es): none; and 0 Excused: none.
2026-03-19 S
The committee(s) on WLA recommend(s) that the measure be PASSED, WITH AMENDMENTS. The votes in WLA were as follows: 4 Aye(s): Senator(s) Lee, C., Chang, Lamosao, DeCorte; Aye(s) with reservations: none ; 0 No(es): none; and 1 Excused: Senator(s) Inouye.
2026-03-16 S
The committee(s) on EIG/WLA has scheduled a public hearing on 03-19-26 3:00PM; Conference Room 224 & Videoconference.
2026-03-12 S
Referred to EIG/WLA, JDC.
2026-03-12 S
Passed First Reading.
2026-03-12 S
Received from House (Hse. Com. No. 273).
2026-03-10 H
Passed Third Reading with Representative(s) Iwamoto voting aye with reservations; none voting no (0) and none excused (0). Transmitted to Senate.
2026-03-06 H
Reported from JHA (Stand. Com. Rep. No. 1184-26), recommending passage on Third Reading.
2026-03-04 H
The committee on JHA recommend that the measure be PASSED, UNAMENDED. The votes were as follows: 8 Ayes: Representative(s) Tarnas, Poepoe, Hashem, Kahaloa, Sayama, Takayama, Garcia, Shimizu; Ayes with reservations: none; Noes: none; and 2 Excused: Representative(s) Belatti, Cochran.
2026-02-27 H
Bill scheduled to be heard by JHA on Wednesday, 03-04-26 2:00PM in House conference room 325 VIA VIDEOCONFERENCE.
2026-02-11 H
Passed Second Reading as amended in HD 1 and referred to the committee(s) on JHA with none voting aye with reservations; none voting no (0) and Representative(s) Holt excused (1).
2026-02-11 H
Reported from WAL (Stand. Com. Rep. No. 200-26) as amended in HD 1, recommending passage on Second Reading and referral to JHA.
2026-02-03 H
The committee on WAL recommend that the measure be PASSED, WITH AMENDMENTS. The votes were as follows: 9 Ayes: Representative(s) Hashem, Morikawa, Belatti, Ichiyama, Poepoe, Woodson, Souza; Ayes with reservations: Representative(s) Iwamoto, Shimizu; Noes: none; and Excused: none.
2026-01-30 H
Bill scheduled to be heard by WAL on Tuesday, 02-03-26 9:00AM in House conference room 411 VIA VIDEOCONFERENCE.
2026-01-26 H
Referred to WAL, JHA, referral sheet 1
2026-01-21 H
Introduced and Pass First Reading.
2026-01-20 H
Prefiled.

Official Summary Text

RELATING TO RAINWATER CATCHMENT SYSTEMS.
Counties; Rainwater Catchment Systems
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)

Current Bill Text

Read the full stored bill text

HB1728

HOUSE OF REPRESENTATIVES

H.B. NO.

1728

THIRTY-THIRD LEGISLATURE, 2026

STATE OF HAWAII

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
Hawaii.
�
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 non-potable uses.
�
Allowing these systems across all zoning
types can reduce strain on public infrastructure, support local
self-sufficiency, and encourage responsible water management.

����
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 non-potable
uses on all properties; and

����
(2)
�
Authorize the counties to regulate and enforce
standards for the use of rainwater catchment systems.

����
SECTION 2.
�
Chapter 46, Hawaii Revised Statutes, is
amended by adding a new section to part I to be appropriately designated and to
read as follows:

����
"
�46-
�
Regulation
of rainwater catchment systems.
�
(a)
�
Under the authority granted to the
counties under section 46‑1.5(13) and (14)(A)(ii), e
ach county shall permit the installation and
operation of rainwater catchment systems for potable and non-potable uses on
all properties, regardless of whether the property is connected to a county
water system.

����
(b)
�

The counties shall adopt rules or ordinances for the regulation and
enforcement of rainwater catchment systems, which include safety, maintenance,
design, and backflow prevention standards to prevent contamination of any
public, county, or private water source.

����
(c)
�

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.

����
(d)
�
As
used in this section:

����
"County water system" means any
public water infrastructure operated or regulated by a department or board of
water supply of the county.

����
"Rainwater catchment system" means
a system designed to collect and store rainwater from rooftops or other
surfaces for potable and non-potable use, including irrigation, toilet
flushing, cleaning, and landscape watering.
"

����
SECTION 3.
�
New statutory material is underscored.

����
SECTION 4.
�
This Act shall take effect upon its approval.

INTRODUCED BY:

_____________________________

Report Title:

Counties;
Rainwater Catchment Systems

Description:

Requires
the counties to allow for the installation and operation of rainwater catchment
systems for potable and non-potable uses on all properties.
�
Authorizes the counties to regulate and
enforce standards for the use of rainwater catchment systems.

The summary description
of legislation appearing on this page is for informational purposes only and is
not legislation or evidence of legislative intent.