HI HB510

Requires the Commission on Water Resource Management to formulate water shortage plans and adopt permit classification systems through formal rulemaking, allowing stakeholder participation in the process

Expands the commission's authority to declare water shortages in areas both within and outside of designated water management areas, including imposing restrictions on well and stream diversion works owners

Limits water shortage declarations to 90 days unless extended by the commission after reviewing hydrologic conditions, and caps water usage restrictions at 20% of a permittee's or owner's last reported monthly usage

Expands public notification requirements to include publication on the commission's website, electronic mail notices to permittees, and maintaining a list of persons requesting notification of water shortage declarations

Takes effect July 1, 2040