Hawaii 2026 Regular Session

Hawaii House Bill HB1728

Introduced
1/21/26  
Refer
1/26/26  
Report Pass
2/11/26  
Refer
2/11/26  
Report Pass
3/6/26  
Engrossed
3/10/26  
Refer
3/12/26  
Report Pass
3/30/26  
Refer
3/30/26  
Report Pass
4/10/26  
Report Pass
4/29/26  
Report Pass
4/29/26  

Caption

RELATING TO RAINWATER CATCHMENT SYSTEMS.

Summary

HB1728 requires each county in Hawaii to allow the installation and operation of rainwater catchment systems on all properties, whether or not the property is connected to a county water system. The bill expressly covers systems used for both potable and nonpotable purposes, such as irrigation, toilet flushing, cleaning, and landscape watering. It is framed as a response to limited water infrastructure and the need to support new housing, sustainable land use, and local self-sufficiency. The measure also preserves a role for county oversight. Counties may require registration, inspection, or notification of rainwater catchment systems when needed to protect public health or water quality, but they may not unreasonably restrict or prohibit their use. The bill defines both “county water system” and “rainwater catchment system,” and it takes effect on July 1, 2026.

Impact

The bill amends Chapter 46, Hawaii Revised Statutes, by adding a new county authority provision that preempts local restrictions inconsistent with the statewide requirement to permit rainwater catchment systems. It affects county zoning and water-related permitting practices by mandating access across all properties and zoning types, while allowing limited county regulation for health and water-quality purposes. The practical effect is to broaden legal acceptance of rainwater harvesting as a supplemental water source for residential and other development.

Sentiment

The bill appears to have broad support in the Legislature. Committee and conference votes were unanimous or near-unanimous, and the bill advanced through Senate Energy and Intergovernmental Affairs, Senate Water, Land, and Agriculture, Senate Judiciary, and both conference committees without recorded opposition. The overall tone reflected support for water resilience, housing development, and sustainable land use.

Contention

The main policy tension is between statewide access to rainwater catchment systems and county authority to regulate them. Supporters emphasized reducing barriers to housing and easing pressure on public water infrastructure, while the bill preserves county power to require registration, inspection, or notification for public health and water-quality reasons. Any concern appears to center on ensuring that county oversight does not become an unreasonable barrier to installation or use.

Companion Bills

No companion bills found.

Previously Filed As

HI SB836

Relating To Water Catchment Systems.

HI SCR118

Requesting The Department Of Health To Convene A Working Group To Assess The Feasibility Of Allowing Business Owners In The State To Utilize Filtered Water Collected By Water Catchment Systems For Business Activities.

HI SR99

Requesting The Department Of Health To Convene A Working Group To Assess The Feasibility Of Allowing Business Owners In The State To Utilize Filtered Water Collected By Water Catchment Systems For Business Activities.

HI HB736

Relating To Wastewater Systems.

HI SB1221

Relating To Stormwater Management Systems.

HI HB1365

Relating To The Department Of Agriculture.

HI SB1186

Relating To Sustainable Food Systems.

HI HB734

Relating To Wastewater Systems.

HI HB505

Relating To Red Hill.

HI HB915

Relating To Water Use.

Similar Bills

HI SB836

Relating To Water Catchment Systems.

HI SB2085

Relating To Water Catchment Systems.

HI SB836

Relating To Water Catchment Systems.

HI SR99

Requesting The Department Of Health To Convene A Working Group To Assess The Feasibility Of Allowing Business Owners In The State To Utilize Filtered Water Collected By Water Catchment Systems For Business Activities.

HI SCR118

Requesting The Department Of Health To Convene A Working Group To Assess The Feasibility Of Allowing Business Owners In The State To Utilize Filtered Water Collected By Water Catchment Systems For Business Activities.

TX SB1589

Relating to the contract requirements for a contract between a single source continuum contractor and the Department of Family and Protective Services.

HI SB768

Relating To Taxation.

HI HB690

Relating To Taxation.