Finding of necessity by local governing body

No municipalities shall exercise the authority hereafter conferred upon municipalities by this article until after its local governing body shall have adopted a resolution finding that: (1) one or more slum or blighted areas exist in such municipality; and (2) the rehabilitation, conservation, redevelopment, or a combination thereof, of such area or areas is necessary in the interest of the public health, safety, morals or welfare of the residents of such municipality.