The legislature of the state of Idaho hereby declares that the public health, interest, safety and welfare requires that all encroachments upon, in or above the beds or waters of navigable lakes of the state be regulated in order that the protection of property, navigation, fish and wildlife habitat, aquatic life, recreation, aesthetic beauty and water quality be given due consideration and weighed against the navigational or economic necessity or justification for, or benefit to be derived from the proposed encroachment. No encroachment on, in or above the beds or waters of any navigable lake in the state shall hereafter be made unless approval therefor has been given as provided in this act.