It is hereby declared that unsanitary or unsafe dwelling and public school accommodations exist in various cities of the state and in the area surrounding such cities; that consequently persons of low income are forced to reside in and use such dwelling and public school accommodations; that these conditions cause an increase in and spread of disease and crime and constitute a menace to the health, safety, morals, and welfare of the citizens of the state and impair economic values; that the clearance, replanning, and reconstruction of the areas in which unsanitary or unsafe housing conditions exist and the provision of safe and sanitary dwelling and public school accommodations at such rentals that persons who now live in unsafe or unsanitary or congested dwelling accommodations or in overcrowded and congested dwelling accommodations can afford to live in safe or sanitary or uncongested dwelling accommodations, are public uses and purposes for which private property may be acquired; and that it is in the public interest that work on such projects be instituted as soon as possible in order to relieve unemployment which constitutes an emergency. The necessity in the public interest for this article is hereby declared as a matter of legislative determination.