Every certificate issued by a governing authority and every recommendation of the commission, unless the proposed use is not harmful to the water and land resources of the stream corridor, will not significantly impede the natural flow of flood waters, and will not result in significant land erosion, stream bank erosion, siltation, or water pollution, shall comply with the following minimum standards:
(1) No land or water use shall be permitted in the flood plain; and
(2) No land or water use shall be permitted within 150 horizontal feet of the watercourse.