Except by consent of the voters, the city’s voluntary floating indebtedness shall not exceed $000000; nor its bonded indebtedness $000000 at any one time. For purposes of calculating the limitation, however, the legally authorized debt of the city in existence at the time this charter takes effect shall not be considered. All city officials and employees who create or officially approve any indebtedness in excess of this limitation shall be jointly and severally liable for the excess.