Conservation easements may be required along all drainage and stormwater rights-of-way in the development and may be required in forested or buffer areas, and also along ponds, marshes, bogs and streams or other watercourses along which drainage rights-of-way are not required. Such easements are intended to help protect existing stands of trees, preserve open space in areas designated for that purpose as part of a cluster development, prevent the siltation of streams and other courses and the erosion of stream banks, other watercourses and adjacent lands. The land subjected to a conservation easement shall be a strip at least 25 feet in width independently located or running adjacent to each side of any required open space, forested area, or drainage or stormwater right-of-way. Such conservation easement shall contain provisions to restrict the removal of trees and ground cover except for the following purposes: removal of dead or diseased trees; thinning of trees and other growth to encourage the more desirable growth; removal of trees to allow for structures designed to impound water; and removal of trees in areas to be flooded for the creation of ponds or lakes. The easements shall also prohibit filling or grading of the lands or the disposal of refuse or waste material of any type within the limits of the easement. Fences, swimming pools, sheds, patios, outdoor cooking facilities, and other improvements are strictly prohibited in all conservation areas.