How do bonds work?
Essentially, once authorization is granted through an election, bonds are sold against the value of property within the boundaries of the district. Prosper ISD has currently sold all the bonds that it can against the current value (those that already live in Prosper ISD). A bond issue would grant the district to sell bonds against the new value (all the new homes and businesses that come to PISD after today). Current home owners grant authorization through an election to sell bonds against the new value (new homes and businesses) that are coming to Prosper ISD.