1. In addition to the bonds specified in section 71.802 the cost of any district of acquiring, constructing, improving, or extending any revenue producing facilities may be met from the proceeds of revenue bonds of the district, payable solely from the operation of such revenue producing facility.

2. Revenue bonds issued under authority of this section shall be payable solely from the revenues derived from the operation of the revenue producing facility acquired, constructed, improved or extended in whole or in part from the proceeds of the bonds. No revenue bond issued pursuant to this section shall constitute an indebtedness of the district within the meaning of any constitutional or statutory restriction, limitation or provision.

3. For the purpose of refunding, extending and unifying the whole or any part of any valid outstanding bonded indebtedness payable from the revenues of a revenue producing facility, the district may issue refunding bonds not exceeding in amount the principal of the outstanding indebtedness to be refunded and the accrued interest to the date of the refunding bonds. The district shall provide for the payment of interest not to exceed the same rate and the principal of the refunding bonds in the same manner and from the same source as was provided for the payment of interest on and principal of the bonds to be refunded.