Hawaiʻi Institute of Rainwater
Your water. Your responsibility. Our support.
Building Hawaiʻi’s Rainwater Harvesting Future
Hawaiʻi Institute of Rainwater advances education, standards and best practices, workforce development, community resilience, and policy coordination to support safe, reliable, and responsible rainwater harvesting throughout Hawaiʻi.
Vision Statement
The Institute sets the benchmark for rainwater harvesting in Hawaiʻi advancing a future where those on catchment become confident, self-reliant Rainwater Harvesters, water availability and quality is assured, and decentralized water systems are recognized as essential infrastructure for resilient, thriving communities.
The Institute advances rainwater harvesting safety, education, and research, integrated water management approaches, and public health in Hawaiʻi by promoting best practices aligned with leading industry standards and other applicable guidance, best available data and science, and community-based knowledge.
Mission Focus
Turning Policy Into Coordinated Action
Act 209 (formerly HB 1728) Relating to Rainwater Catchment Systems
The final bill was signed into law on July 8, 2026 by Governor Josh Green. This Act requires counties to allow installation and operation of rainwater catchment systems for potable and nonpotable uses on all properties. Counties may require registration, inspection, or notification when necessary to protect public health or water quality but may not unreasonably restrict or prohibit their use.
This is a significant development and makes HIOR's timing particularly relevant. HIOR is designed to build trust, cooperation and coordination.
Public agencies, private partners, and philanthropic organizations are invited to commit resources, underwrite priority initiatives, and champion HIOR’s work to strengthen Hawaiʻi’s Rainwater Harvesting future.
Why Rainwater Harvesting Matters
Rainwater catchment is the primary water supply for tens of thousands of Hawaiʻi residents. Individual household systems are not regulated in Hawaiʻi, placing all responsibility for water supply, system maintenance, water quality, and safe use directly with the owner/user.
If you’re on catchment, you are the Water Department.
HIOR collaborates with industry partners in the guidance, standards, training, and support for Rainwater Harvesters to manage their water supply responsibility confidently and successfully.
The quality of your water is a direct link to the quality of your health.
HIOR assists to better understand and manage rainwater systems responsibly. Better quality of water, better quality of our health.
Your partnership can help shape the future of Rainwater Harvesting in Hawaiʻi. By contributing funding, expertise, resources, or community connections, educators, nonprofit leaders, industry partners, government stakeholders, and concerned residents can help expand public education, develop practical guidance, strengthen informed leadership, and build clear accountability for the future of Hawaiʻi’s Rainwater Harvesting communities.
Big ideas. Real impact.
Join us today.
Invest in, partner with, and/or sponsor HIOR to build Hawaiʻi’s clean water future through shared leadership, practical solutions, and lasting community impact.
Hawaiʻi’s Rainwater Harvesting future starts now.
HIOR exists to build a framework that brings five pillars into coordinated action:
Education and public awareness
Standards and professionalization
Workforce development and training
Community resilience & water security
Policy, partnership and system change through cooperation and coordination.
This approach will strengthen credibility, generate meaningful data, build strategic partnerships, and develop well-defined projects.