The authority may not issue bonds or incur any form of continuing obligation or indebtedness payable from ad valorem taxes for purposes of effecting improvements comprehended in the plan of organization and administration of the authority, or incur any indebtedness in the form of a continuing charge on lands or other physical properties within the authority, unless the proposition has been submitted to the qualified voters of the authority, or in appropriate cases the qualified voters of a defined area within the authority, and is approved by a majority of the electors voting on the proposition.