PUC §727.5: (a) In establishing rates for water service, the commission shall consider, and may establish, separate charges for costs associated with customer service, facilities, variable operating costs, includ

(a) In establishing rates for water service, the commission shall consider, and may establish, separate charges for costs associated with customer service, facilities, variable operating costs, including fixed and variable costs associated with supplying the water, or other components of the water service provided to water users. (b) The commission shall consider, and may authorize, a water corporation to assess a fee for future water service, or a reservation charge for future water service, for persons or entities occupying or owning property within the service territory of the water corporation. (c) The commission shall consider, and may authorize, a water corporation to establish a balancing account, rate stabilization fund, or other contingency fund, the purpose of which shall be the long-term stabilization of water rates. (d) (1) The commission shall consider, and may authorize, a water corporation to establish programs, including rate designs, for achieving conservation of water and recovering the cost of these programs through the rates. (2) (A) Upon application by a water corporation with more than 10,000 service connections, the commission shall consider, and may authorize, the implementation of a mechanism that separates the water corporation’s revenues and its water sales, commonly referred to as a “decoupling mechanism.” (B) An authorized decoupling mechanism shall be designed to ensure that the differences between actual and authorized water sales do not result in the overrecovery or underrecovery of the water corporation’s authorized water sales revenue. (C) An authorized decoupling mechanism shall not enable the water corporation to earn a revenue windfall by encouraging higher sales. (D) The water corporation may only submit an application to the commission pursuant to this paragraph as part of its triennial general rate case application described in Section 455.2, unless the commission and the water corporation mutually agree for the application to be otherwise submitted. (e) In establishing rates for recovery of the costs of used and useful water plant, the commission may use a capital structure and payback methodology that maintains the reliability of water service, minimizes the long-term cost to ratepayers, provides equity between present and future ratepayers, and affords the utility an opportunity to earn a reasonable return on its used and useful investment, attract capital for investment on reasonable terms, and ensure the financial integrity of the utility.