Any appeal, the granting of which would allow a structure within the required setbacks from water bodies, tributary streams or wetlands or within the Resource Protection District, may only be granted if the Board finds that the proposed construction will not result in unsafe or unhealthful conditions; erosion or sedimentation; water pollution; or damage to spawning grounds of fish, aquatic life or other wildlife habitats and will conserve shoreland vegetation and, to the extent possible, visual access to waters as viewed from public facilities, points of public access to waters and natural beauty and will avoid problems with floodplain development and use.