Any person desiring to have the water mains within the city extended, and being willing to advance the whole expense of such extension and also, in designated areas, being willing to advance the additional expenses necessary for aid to construction of supply lines, pumping plants, reservoirs and related facilities, may make application to the city by petition containing a description of such proposed extension, accompanied by a map showing the location thereof, which petition shall also contain an offer to advance the whole expense of making the same as the expense shall be certified to by the public utilities director, and to enter into a contract for payment of such expense. (Prior code § 49-6-73)