70 ILCS 605/6-6
The commissioners may, without court approval, borrow money to an amount not exceeding 90% of the amount of assessments, or one or more installments of assessments, unpaid at the time of the borrowing, for the performance of any work, whether original, additional, repair or maintenance, which they may be authorized to perform, or for the payment of any indebtedness they may have lawfully incurred, or for any other lawful purpose. They may evidence the same by notes or bonds in registered form bearing interest at a rate not to exceed the rate of interest payable on the assessment, and not running beyond one year after the date that the assessment or last installment of the assessment against which the money is borrowed will fall due. Such notes or bonds shall not be held to make the commissioners personally liable for the money borrowed, but shall constitute a lien upon such assessments or installments of assessments (and all interest becoming due thereon) for the repayment of the principal and interest thereof.
70 ILCS 605/6-6