N.Y. Gen. Mun. Law § 111

§ 111. Contracts. Two or more municipalities are hereby empowered to\nenter into a contract to provide for a common supply of water, including\njoint acquisition, construction, operation and maintenance. Such\ncontract shall provide for the method of acquisition or construction of\nthe common supply; the management and operation of the system; the\nmethod of fixing the proportionate share of each participating\nmunicipality and of making contributions; the method of making annual\nadjustments of the proportionate shares of the annual cost and expense;\nthe method of collection of water rates and other charges, and\nenforcement thereof; the accumulation of reserves; the fixing of rate\nschedules and other charges; the adoption of rules and regulations\ncovering the operation of the system and the conditions of sale; the\nadjudication of disputes and all other matters necessary to effectuate\nsuch an arrangement.\n