Under section 2 of the Act, when a “development planning area has been established, the Minister shall, (a) cause to be carried out an investigation and survey of the environmental, physical, social and economic conditions affecting the development planning area or any part of it; and (b) cause a proposed development plan for the planning area or part of it to be prepared, within a period of two years or such other period of time as the Minister considers appropriate.” The Act prescribes which h