The petition shall: clearly describe the area’s location, boundaries, and problems to be addressed by the establishment of a watershed association; describe the public benefit or the public health, safety, or welfare that would be promoted by establishing a watershed project for watershed protection, flood prevention, recreation, soil conservation, drainage, or the conservation, development, storage, use, and disposal of water for any beneficial purpose; and request the establishment of a watershed association for the purposes listed in item (2) of this subsection. A petition is valid only if signed by at least one–third of the landowners or the owners of at least one–third of the land in a watershed or subwatershed area.