All funds and property, real and personal, of the merging district or districts, shall vest in and become the property of the merger district. Unless the agreement of merger provides to the contrary, any outstanding indebtedness of any form, owed by the districts, shall remain the obligation of the area of the original debtor district; and the commissioners of the merger district shall make such levies, assessments, or charges for service upon such area or the users therein as shall pay off such indebtedness at maturity.