The department is authorized and directed to make an inventory of existing hospitals and medical facilities, including, but not restricted to, public, nonprofit and proprietary hospitals and other medical facilities, to accumulate pertinent comparable statistical data from existing hospitals and medical facilities, to survey the need for construction or expansion of hospitals and, on the basis of such statistical data, inventory and survey, and to develop a program for the construction or expansion of such public and other nonprofit hospitals and medical facilities as will, in conjunction with existing facilities, afford the necessary physical facilities for furnishing adequate hospital, clinic, and other essential health services without duplication or fragmentation of such facilities or services to all the people of the state.