A. Where a subdivision is traversed by a watercourse, drainageway, channel, or stream, a stormwater easement or drainage right-of-way shall be provided conforming substantially to the lines of the watercourse, and of the width and construction, or both, as will be adequate for the purpose. Whenever 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.
B. Where topography or other conditions are such as to make impractical the inclusion of drainage facilities within road rights-of-way, perpetual, unobstructed easements of at least fifteen 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 plat. Drainage easements shall be carried from the road to a natural watercourse or to other drainage facilities.
C. When a proposed drainage system will carry water across private land outside the subdivision, appropriate drainage rights must be secured and indicated on the plat.
D. The applicant shall dedicate, either in fee or by drainage or conservation easement, land on both sides of existing watercourses to a distance to be determined by the city council.
E. Low-lying lands along watercourses subject to flooding or overflowing during storm periods, whether or not included in areas for dedication, shall be preserved and retained in their natural state as drainage ways. A hydrology report and construction drawings which preserve the flow characteristics of the drainageway may allow construction within the low-lying land.
(Ord. 1179 § 4.5(C))