It is hereby found and declared that there exist in Montgomery County blighted areas, or slum conditions which require rehabilitation with the aid and assistance of Montgomery County; that the existence of such areas contributes to the spread of crime and disease, constitutes an economic and moral liability, decreases the tax base, reduces tax revenues, increases juvenile delinquency, aggravates traffic conditions and causes numerous traffic problems due to poor street design and layout; that the prevention and elimination of slum and blighted areas is a matter of public policy of the State of Maryland and Montgomery County. It is further found and declared that the existence of these conditions makes it necessary to acquire private property for urban renewal development and redevelopment and such acquisition is hereby declared to be for a public purpose. (Mont. Co. Code 1965, § 26-2; 1961, ch. 821, § 1.)