Haw. Rev. Stat. § 46-104: County powers.

A county may exercise any power necessary and convenient to establish tax increment districts, including the power to:

(1) Create tax increment districts and determine the boundaries of the districts;

(2) Issue tax increment bonds;

(3) Deposit tax increments into the tax increment fund created for a tax increment district; and

(4) Enter into agreements, including agreements with the redevelopment agency and owners or developers of project lands and bondholders, determined to be necessary or convenient to implement redevelopment plans or community development plans, as the case may be, and achieve their purposes.