110 ILCS 525/6

Enforcement of contract. The provisions of this Act and of any resolution or other proceeding authorizing the issuance of bonds shall constitute a contract with the holders of such bonds and the provisions thereof shall be enforceable by mandamus, injunction or other appropriate civil action in the circuit court to enforce and compel the performance of all duties required by this Act and by any resolution authorizing the issuance of bonds adopted responsive hereto.