1. Where a subdivision is traversed by a watercourse, drainageway, channel or stream, there shall be provided a storm water easement or drainage right-of-way conforming substantially to the lines of such watercourse, and of such width and/or construction as will be adequate for the purpose. Wherever possible, it is desirable that the drainage be maintained by an open channel with landscaped banks and adequate width, for maximum potential volume of flow.
2. Where topography or other conditions are such as to make the inclusion of drainage facilities within road rights-of-way impractical, perpetual unobstructed easements at least 15 feet in width for such drainage facilities shall be provided across property outside the road lines and with satisfactory access to the road. Easements shall be indicated on the final plat. Drainage easements shall be carried from the road to a natural watercourse or to other drainage facilities.
3. When a proposed drainage system will carry water across private land outside the subdivision, appropriate drainage rights and easements may be required and indicated on the final plat.
4. The applicant shall dedicate, either in fee simple title, or by drainage or conservation easement, land on both sides of existing watercourses, to a distance to be determined by the Planning Commission, based on the appropriate floodway and floodway fringe zoning district delineations.
5. Low-lying lands along watercourses subject to flooding or overflow during storm periods, whether or not included in areas for dedication, shall be preserved and retained in their natural state as drainageways. Such land or lands subject to periodic flooding shall not be computed in determining the number of lots to be utilized for average density procedure, nor for computing the area requirements of any lot.