All districts previously created under the provisions of the Water and Sanitation District Act and all proceedings previously taken by the districts, including any elections that may have been held in the districts on the question of the issuance of bonds and that have carried, are validated, ratified and confirmed. Where district bonds have been previously approved by the voters but not yet issued, the bonds may be issued under the provisions of the Water and Sanitation District Act, and where the bonds are to be general obligations of the issuing district, the bonds shall be payable from taxes to be levied on all taxable property in the district as required by the Water and Sanitation District Act. All bonds approved by the voters and to be issued shall, when issued, constitute valid obligations of the districts in accordance with their terms.