An authority may contract to buy from the joint system water required for its present or future requirements, including the capacity and output, or a portion or share of one or more specified projects. An authority also may contract for the collection or treatment of wastewater, including present or future capacity, or a portion or share of another project. The creation of a joint system is an alternative method whereby an authority may obtain the benefits and assume the responsibilities of ownership in a project, so a contract may provide that the authority forming the contract is obligated to make a payment required by the contract whether or not a project is completed, operable, or operating notwithstanding the suspension, interruption, interference, reduction, or curtailment of the output of a project or the water contracted for, and that the payments under the contract are not subject to reduction, whether by offset or otherwise, and are not conditioned upon the performance or nonperformance of the joint system or any other member of the joint system under the contract or any other instrument. A contract with respect to the sale or purchase of capacity or output, or a portion or share of them, of a project entered into between a joint system and its member authorities also may provide that if an authority or authorities default in the payment of its or their obligations with respect to the purchase of the capacity or output, or a portion or share of them, in that event the remaining member authorities which are purchasing capacity and output under the contract are required to accept and pay for and are entitled proportionately to and may use or otherwise dispose of the capacity or output which was to be purchased by the defaulting authority.

A contract concerning the sale or purchase of capacity and output from a project may extend for a period not exceeding fifty years from the date of the contract and may be renewable and extended upon terms as the parties may agree for not exceeding an additional fifty years; and the execution and effectiveness is not subject to any authorizations or approvals by the State or any agency, commission, or instrumentality or political subdivision of them.

Payments by an authority under a contract for the purchase of capacity and output from a joint system may be made from the revenues derived from the ownership and operation of the water system of the authority or from such other sources of funds as may be available, including any amounts received as payments in lieu of taxes. An authority may not pledge its full faith, credit, and taxing power to secure its obligations to the joint system or the bonds of the joint system. An authority is obligated to fix, charge, and collect rents, rates, fees, and charges for water or sewer services, facilities, and commodities sold, furnished, or supplied through its water or sewer system sufficient to provide revenues adequate to meet its obligations under any contract and to pay any and all other amounts payable from or constituting a charge and lien upon the revenues, including amounts sufficient to pay the principal of and interest on general obligation bonds, if any, heretofore or hereafter issued by the authority for purposes related to its water or sewer system.

An authority that is a member of a joint system may furnish the joint system with money derived from the ownership and operation of its water or sewer system or facilities and provide the joint system with personnel, equipment, and property, both real and personal, and from any other sources legally available to it for such purposes. An authority also may provide services to a joint system.

A member of a joint system may contract for, advance, or contribute funds derived from the ownership and operation of its water or sewer system or facilities or from another legal source to a joint system as agreed upon by the joint system and the member, and the joint system shall repay the advances or contributions from the proceeds of bonds, operating revenue, or other funds of the joint system, together with interest as agreed upon by the member and the joint system.