The trend of population growth in the state in recent decades has been to the larger cities and the areas adjacent thereto to the degree that some of such cities contain over one-half the population of the respective counties in which such cities are located. Such growth has given rise to the need for buildings, structures, and facilities to be used jointly by such cities and the respective counties in which they are located, thereby effecting economies of operation and adding to the effectiveness of such cities and counties, aiding in the use by the inhabitants of such cities and counties, and alleviating the inconvenience of separate buildings, structures, and facilities caused by such growth to such inhabitants. The purpose of sections 13-1301 to 13-1312 is to provide a means whereby buildings, structures, and facilities can be acquired, constructed, remodeled, or renovated and financed for use jointly by such cities and the respective counties in which they are located.