It is hereby found and declared that there exist in localities throughout the state, slum and blighted areas (as herein defined) which constitute a serious and growing menace, injurious and inimical to the public health, safety, morals and welfare of the residents of the state; that the existence of such areas contributes substantially and increasingly to the spread of disease and crime, necessitating excessive and disproportionate expenditures of public funds for the preservation of the public health and safety, for crime prevention, correction, prosecution, punishment and the treatment of juvenile delinquency and for the maintenance of adequate police, fire and accident protection and other public services and facilities, constitutes an economic and social liability, substantially impairs or arrests the sound growth of communities and retards the provision of housing accommodations; that this menace is beyond remedy and control solely by regulatory process in the exercise of the police power and cannot be dealt with effectively by the ordinary operations of private enterprise without the aids herein provided; that the elimination of slum conditions or conditions of blight, the acquisition and preparation of land in or necessary to the development of slum or blighted areas and its sale or lease for development or redevelopment in accordance with general plans and redevelopment plans of communities and any assistance which may be given by any state public body in connection therewith, are public uses and purposes for which public money may be expended and private property acquired; and that the necessity in the public interest for the provisions hereinafter enacted is hereby declared as a matter of legislative determination.