Public utilities; combination of plants or systems; pledge of revenues.

(1) All such reservoirs, sewerage systems, trunk sewers, intercepting sewers, pumping stations, wells, intakes, pipelines, distribution systems, purification works, collecting systems, treatment and disposal works, airports, hospitals, jails and golf courses, and gas plants and distribution systems, whether heretofore or hereafter constructed or operated, are considered a public utility within the meaning of any constitutional or statutory provision for the purpose of acquiring, purchasing, owning, operating, constructing, equipping and maintaining such works.

(2) Whenever any municipality shall decide to avail itself of the provisions of this chapter for the extension or improvement of any existing utility plant or system, any then-existing plant or system may be included as a part of a whole plant or system and any two or more utilities may be included in one project hereunder. The revenues of all or any part of any existing plants or systems or any plants or systems constructed hereunder may be pledged to secure moneys advanced for the construction or improvement of any utility plant or system or any part thereof or any combination thereof.