An authority shall not exercise the authority conferred upon municipalities or communities by this chapter until after the local governing body shall have adopted a resolution finding that:
(1) One or more slum or blighted areas shall exist in such municipality or community; 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 or community.