Establishment of commission; members; initial costs and funding. (a) Establishment of commission. Two or more municipalities, at least one of which is located in whole or in part in the county of Cook, Kane, Kendall, Lake, McHenry, or Will and has 140,000 or more inhabitants at the time of establishment of a regional water commission, excluding cities of 500,000 or more inhabitants, may acquire, either by purchase or construction, a waterworks system or a common source of supply of water, or both, and may operate jointly a waterworks system or a common source of supply of water, or both, and improve and extend the same, as provided in this Division. The municipality meeting the requirement to have 140,000 or more inhabitants as required by this paragraph must have attained that population as of December 16, 2021 (the effective date of Public Act 102-684). The corporate authorities of the municipalities desiring to avail themselves of the provisions of this Division shall establish a regional water commission by adopting an ordinance determining and electing to acquire and operate jointly a waterworks system or a common source of supply of water, or both, as the case may be, and approving an intergovernmental agreement among the municipalities establishing the regional water commission. This agreement may be amended at any time upon the adoption, by the corporate authorities of all member municipalities, of ordinances approving the amendment to the agreement. (b) Addition or withdrawal of members; dissolution. The agreement may provide for additional municipalities to join the commission upon adoption of an ordinance by the corporate authorities of the joining municipality and, upon such consents, conditions, and approvals of the board of commissioners and of existing member municipalities as shall be provided in the agreement. The agreement shall provide the manner and terms on which a municipality may withdraw from membership in the commission and on which the commission may terminate and dissolve in whole or in part. (c) Filing of agreement. Promptly upon entering into the agreement or any amendment to it, a copy of such agreement or amendment shall be filed in the office of the Secretary of State. Promptly upon the addition or withdrawal of a municipality, or, upon the dissolution of the commission, that fact shall be certified by an officer of the commission to the Secretary of State. (d) Development costs. A municipality whose corporate authorities adopted an ordinance and approved an intergovernmental agreement to acquire and operate jointly a waterworks system or a common source of supply of water, or both, as the case may be, under the provisions of this Division, may from time to time pay, advance, or obligate itself to the commission to bear a proportionate share of the development costs, including principal and interest, of any project proposed by the commission, including plans, feasibility reports, and engineering, even if the project is never constructed or water is never supplied by the commission to such municipality. Whenever the corporate authorities of a municipality determine that the municipality will pay, advance, or be obligated for its proportionate share of development costs as provided in this subsection, they shall adopt an ordinance declaring their intention that the municipality will do so, fix the maximum amount of the municipality's share of the cost the municipality proposes to pay or that the municipality will advance or to obligate the municipality for, and fix the period over which it is proposed to pay the obligation (not exceeding 10 years), if such obligation is to be paid in installments. The time of payment of any such installment obligation may be extended for a period not exceeding 10 years from the final maturity date of the original obligation. On and after the date such ordinance becomes effective, the municipality shall include an amount sufficient to pay the annual installments of its obligation each year in the next succeeding appropriation ordinances. The commission may require that if any such municipality whose corporate authorities determined to pay, to advance, or to obligate the municipality to the commission for development costs defaults in such payments, advances, or obligations, then the remaining municipalities whose corporate authorities have determined to pay, to advance, or to obligate the respective municipalities to the commission for development costs will be required to pay for all or a portion of the payments, advances by, or obligations of the defaulting municipality. No prior appropriation shall be required for the corporate authorities of a municipality to authorize the payments, advances, or obligations herein provided for. Whenever the corporate authorities of a municipality have obligated the municipality for development costs as herein provided and after the effective date of the ordinance under which the municipality became obligated for a specific amount for development costs of a project and after approval of such obligation by the commission, the commission is authorized to borrow funds temporarily for payment of such development costs in advance of permanent financing. The commission may from time to time and pursuant to an appropriate ordinance or resolution borrow money and issue its interim notes to evidence borrowings for such purpose, including all necessary and incidental expenses in connection therewith. An ordinance or resolution authorizing the issuance of such notes shall describe the project and the development costs to be undertaken and specify the principal amount, rate of interest as authorized under Section 2 of the Bond Authorization Act, and the maturity date, which shall coincide with the due date of the obligations or the installments thereof incurred by the respective municipalities pursuant to this Section not, however, to exceed 10 years from date. Contemporaneously with the issuance of revenue bonds under Section 11-135.5-30, all outstanding interim notes issued for development costs of a project though they have not then matured shall be paid, both principal and interest to date of payment, from funds derived from the sale of revenue bonds for the permanent financing of any such project for which interim notes may have been issued and such interim notes shall be surrendered and cancelled, or, in the alternative, the commission may determine to pay such interim notes out of receipts from other sources available to the commission, including grants and loans. Whenever a member municipality has incurred development costs for a project and has advanced funds or otherwise obligated itself for the payment of such costs, the commission is authorized to accept assignment of such debt instruments and the payment obligations thereunder and to thereafter make all necessary payments to meet such obligations out of receipts from other sources available to the commission, including grants and loans, or provide for credits against amounts otherwise due to the commission from the municipality, including interest on the amounts due. As used in this subsection, "development costs" means the costs of development of a project, including debt incurred and principal and interest payments, whether incurred by the commission or a member municipality. (e) Construction and operating costs. A municipality, the corporate authorities of which adopted an ordinance and approved an intergovernmental agreement to acquire and operate jointly a waterworks system or a common source of supply of water, or both, as the case may be, under the provisions of this Division, may from time to time pay, advance, or obligate itself to the commission to bear a proportionate share of the construction and operating costs of any project proposed by the commission. Whenever the corporate authorities of a municipality determine that the municipality will pay, advance, or be obligated for its proportionate share of construction or operating costs as above provided, they shall adopt an ordinance declaring their intention to do so, fix the maximum amount of the municipality's share of the cost it proposes to pay, to advance, or to obligate itself for, and fix the period over which it is proposed to pay the obligation, if such obligation is to be paid in installments. On and after the date such ordinance becomes effective, the municipality shall include an amount sufficient to pay the annual installments of its obligation each year in the next succeeding appropriation ordinances. The commission may require that if any such municipality whose corporate authorities determined that the municipality will pay, advance, or be obligated to the commission for construction or operating costs defaults in such payments, advances, or obligations, then the remaining municipalities whose corporate authorities have determined that the municipality will pay, advance, or be obligated to the commission for construction or operating costs will be required to pay for all or a portion of the payments, advances by, or obligations of the defaulting municipality. No prior appropriation shall be required for the corporate authorities of a municipality to authorize the payments, advances, or obligations herein provided for. Whenever a municipality, through its corporate authorities, has paid, advanced, or obligated the municipality for development, construction, or operating costs as herein provided, the commission may contract with the municipality, on such terms as may be agreed, for the repayment to the municipality by the commission of any payment or advance made by the municipality to the commission and to charge, in addition to all other charges and rates authorized under this Division, such rates and charges for water sold by the commission as shall be necessary to provide for such repayment. In addition, any payment or advance of such costs made by a municipality pursuant to this Section may be repaid by the commission to the municipality: (i) from the proceeds of revenue bonds authorized to be issued by the commission pursuant to this Division; (ii) out of receipts from other sources available to the commission, including grants and loans; or (iii) by the commission providing credits against amounts otherwise due to the commission from the municipality, including interest on the amounts due. Whenever a member municipality has incurred construction and operating costs for a project and has advanced funds or otherwise obligated itself for the payment of such costs, the commission is authorized to accept assignment of such debt instruments and the payment obligations thereunder and to thereafter make all necessary payments to meet such obligations: (i) from the proceeds of revenue bonds authorized to be issued by the commission pursuant to this Division; (ii) out of receipts from other sources available to the commission, including grants and loans; or (iii) by the commission providing credits against amounts otherwise due to the commission from the municipality, including interest on the amounts due. As used in this subsection, "construction and operating costs" means the costs of construction and operation of a project, including debt incurred and principal and interest payments, whether incurred by the commission or a member municipality. (f) Commission facilities. A waterworks system or a common source of supply of water, or both, purchased or constructed by the commission: (1) may be located within or without the corporate limits of any member municipality; (2) may include, or may consist of, without limitation, facilities for receiving, storing, and transmitting water from any source for supplying water to member municipalities and other purchasers of water from the commission; and (3) may include, without limitation, facilities that are developed, acquired, constructed, extended, or improved by the commission that may at any time be owned by another unit of local government if such facilities will serve the waterworks system or provide a common source of supply of water for the commission.