HI SB21

Requires the Public Utilities Commission to establish automatic adjustment mechanisms for water carriers by July 1, 2026, including a water carrier inflationary cost index that ties rate adjustments to annual percent changes in a Product Price Index

Caps the automatic rate adjustment at plus or minus 5% per year, applied annually for two consecutive years with a general rate case required every third year

Reduces the notice period for automatic adjustment mechanism surcharge changes from 45 days to 30 days for water carriers filing tariff modifications

Grants the commission authority to waive or exempt water carriers from any requirements under the Hawaii Water Carrier Act if determined to be unjust, unreasonable, or not in the public interest

Adds a statutory definition of "automatic adjustment mechanism" as any rate adjustment allowing water carriers to change rates between formal rate cases