(A) General. The Plan Commission shall not recommend for approval any plat of a subdivision which does not make adequate provision for storm or flood water runoff. The drainage system shall be separate and independent of any sanitary sewerage system. Storm sewers, where required, shall be designed according to the methods recommended by the City Engineer, endorsed by the Plan Commission Advisory and approved by the Plan Commission, and a copy of the design computations shall be submitted along with plans. Inlets shall be provided so that surface water is not carried across or around any intersection, nor for a distance of more than 400 feet in any gutter. Surface water drainage patterns shall be shown for each lot and block.
(B) Requirements for storm sewers.
(1) The applicant may be required by the Plan Commission to carry away by pipe or open ditch any spring or surface water that may exist either previously to, or as a result of, the subdivision. The drainage facilities shall be located in the road right-of-way where feasible, or in perpetual unobstructed easements of appropriate width. Drain facilities shall be provided under driveways so that the flow of water in ditches is not impeded.
(2) Where a public storm sewer is accessible, the applicant shall install storm sewer facilities; or, if no outlets are within a reasonable distance, adequate provision shall be made for the disposal of storm waters subject to the specifications of the City Engineer.
(3) Where conditions exist that would require a sewer size larger than what is normally required for a particular size subdivision, the city or county shall bear the additional cost for the oversized facility, over and above what would be required for the subdivision alone.
(4) If the Commission determines that a connection to a public storm sewer will eventually be provided as shown in existing local plans and programs, the developer shall make arrangements for future storm water disposal in the subdivision by a public sewerage system at the time the plat receives final approval. Provision for the connection shall be incorporated by inclusion in the performance bond required for the subdivision plat.
(C) Poor drainage areas. Whenever a plat is submitted for an area which is subject to ponding, the Plan Commission may approve the application provided that the applicant fills the affected area of the subdivision to an elevation as determined by the City Engineer.
(D) Flood plain areas. The Plan Commission shall, when it deems it necessary for the health, safety, or welfare of the present and future population of the area and necessary to the conservation of water, drainage and sanitary facilities, prohibit the subdivision of any portion of the property which lies within the flood plain. Any approvals within the flood plain shall, at a minimum, meet the requirements of the State Department of Natural Resources.
(E) Drainage easements. Where a subdivision is traversed by a watercourse, drainageway, channel, or stream, the subdivider shall provide a storm water easement or drainage right-of-way conforming substantially to the lines of such watercourse, and of such width and construction as will be acceptable to the City Engineer. The easement shall be adequately monumented; and, whenever possible, it is desirable that the drainage be maintained by open channel with landscaped banks.
(Ord. 29-1984, passed 8-14-84) Penalty, see § 152.99