65 ILCS 5/11-135-3
Such a commission shall organize by appointing a chairman from its own members and a clerk and treasurer, who need not be commissioners. It shall adopt its own rules of procedure and provide for its meetings. The commission has full and complete supervision, management, and control of the waterworks system, or the common source of supply of water, or both, as provided in the ordinances or resolutions for acquiring and operating the same, and in their maintenance, operation, and extension. The commission is authorized to contract with the municipalities which established the commission for a supply of water to those municipalities, for a period not exceeding 50 years, and the corporate authorities of those municipalities are authorized to enter into contracts with the commission.
The commission is authorized to develop, promote and provide for recreational facilities on property acquired in and for the operation of its common source of supply of water and to include reasonable charges for such recreational facilities as part of the cost of operation and maintenance of the waterworks system.
Any 2 or more water commissions organized under this Division 135 may, by resolution adopted by each commission and ratified by the corporate authorities of each of the municipalities comprising each of the water commissions agree to the joint purchase, construction, operation, improvement or extension, or any combination thereof, of either or both a waterworks system and a common source of supply of water for those commissions. When such an agreement has been executed, the water commissions entering into that agreement may jointly issue revenue bonds for the projects subject to the agreement in the same manner and subject to the same conditions as are provided in this Division 135 in the case of an individual water commission.
Any additional municipality may join and become a part of the system provided for in this Division 135 in the same manner as if participating at the time of formation if approved by majority vote of the water commissioners and such approval is ratified by resolution of the corporate authorities of a majority of the municipalities constituting the commission; except that if a system is composed of two municipalities, only the approval of a majority of the water commissioners is required to accept an additional municipality to the system. If a municipality has been a continuous customer of the same water commission for a minimum of 20 years, receives at least 90% of its water from the water commission, and the population of the municipality exceeds 25% of the population of the then current member municipalities in the water commission, that municipality shall become a part of the system. In such event the name of the water commission shall be changed either to include the joining municipality's name or to provide another name that is indicative of the area. The membership of the water commission shall be enlarged to include a member from such joining municipality.Any additional municipality or water commission may join and become a part of the system provided for in this Division 135 in the same manner as if participating at the time of formation if approved by majority vote of the water commissioners and such approval is ratified by resolution of the corporate authorities of a majority of the municipalities or water commissions constituting the commission; except that if a system is composed of two municipalities, only the approval of a majority of the water commissioners is required to accept an additional municipality or water commission to the system. If a municipality or water commission has been a continuous customer of the same water commission for a minimum of 20 years, receives at least 90% of its water from the water commission, and the population of the municipality or water commission exceeds 20% 25% of the population of the then current member municipalities in the water commission, that municipality or water commission shall become a part of the system. In such event the name of the water commission may shall be changed either to include the joining municipality's or water commission's name or to provide another name that is indicative of the area. The membership of the water commission shall be enlarged to include a member from such joining municipality or water commission.
65 ILCS 5/11-135-3