Ariz. Rev. Stat. § 45-2457
B. The authority shall operate in accordance with all of the following rules of operation:
2. The authority may distribute long-term storage credits accrued or purchased with general fund appropriations, other than general fund appropriations for replenishment under chapter 15, article 3 of this title, for both of the following:
(a) To make water available to a municipal and industrial user of Colorado river water in this state that is outside of the service area of CAWCD, if both of the following apply:
(b) To make water available to CAWCD to the extent necessary for CAWCD to meet the demands of its municipal and industrial subcontractors, if all of the following apply:
8. For each county within the CAWCD service area, on a determination by the authority that the number of long-term storage credits accrued or purchased with monies deposited in the fund in accordance with section 48-3715.03, subsection B exceeds the needs specified in paragraph 7 of this subsection for that county, the authority shall distribute those excess long-term storage credits to municipal water providers within that county that are at the time of distribution experiencing surface water supply shortages not associated with the central Arizona project. The authority shall distribute to each such municipal water provider the lesser of the following number of long-term storage credits: