Any municipal corporation, the City of New Orleans excepted, or any district created for the purpose of supplying the public with a public utility may, for the purpose of constructing, acquiring, extending, or improving any revenue producing public utility, within or without the limits of the municipality or district, issue bonds secured exclusively, principal and interest, by mortgage on the lands, buildings, machinery, and equipment, and by pledge of the income and revenues of the public utility.
La. R.S. § 33:4221