(A) Location. The applicant may be required by the Planning and Zoning 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. Such drainage facilities shall be located in the road right-of-way, where feasible, or in perpetual unobstructed easements of appropriate width and shall be constructed in accordance with the city’s Standard Specifications for Construction, as amended.
(B) Accessibility to public storm sewers.
(1) 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 stormwaters, subject to the specifications of the Director of Public Works or his or her designee. However, in subdivisions containing lots less than 15,000 square feet in area and in business and industrial districts, underground storm sewer systems shall be conducted to an approved outfall. The Director of Public Works or his or her designee shall conduct inspections of facilities.
(2) If a connection to a public storm sewer will be provided eventually, as determined by the Director of Public Works or his or her designee and the Planning and Zoning Commission, the developer shall make arrangements for future stormwater disposal by a public utility system at the time the plat receives final approval. Provision for such connection shall be incorporated by inclusion in the bond or other surety required for the subdivision plat.
(C) Accommodation of upstream drainage areas. A culvert or other drainage facility shall in each case be large enough to accommodate potential runoff from its entire upstream drainage area, whether inside or outside the subdivision. The Director of Public Works or his or her designee shall determine the necessary size of the facility based on the provisions of the city’s Standard Specifications for Construction, as amended, assuming conditions of maximum potential watershed development permitted by the zoning ordinance.
(D) Effect on downstream drainage areas. The Director of Public Works or his or her designee shall also study the effect of each subdivision on existing downstream drainage facilities outside the area of the subdivision. City drainage studies, together with such other studies as shall be appropriate, shall serve as a guide to needed improvements. Where it is anticipated that the additional runoff incident to the development of the subdivision will overload an existing downstream drainage facility, the Planning and Zoning Commission may withhold recommendation of approval of the subdivision until provision has been made for the improvement of said potential condition. No subdivision shall be approved unless adequate drainage will be provided to an adequate drainage watercourse or facility.
(E) Areas of poor drainage. Whenever a plat is submitted for an area which is subject to flooding, the Planning and Zoning Commission may recommend approval of such subdivision, provided that the applicant fills the affected area of said subdivision to an elevation sufficient to place the elevation of streets and lots at a minimum of 12 inches above the elevation of the maximum probable flood as determined by the Director of Public Works or his or her designee. The plat of such subdivision shall provide for an overflow zone along the bank of any stream or watercourse in a width which shall be sufficient in times of high water to contain or move the water. No fill shall be placed in the overflow zone, nor shall any structure be erected or placed therein. The boundaries of the overflow zone shall be subject to approval by the Director of Public Works or his or her designee. Subdivision of areas of extremely poor drainage shall be discouraged.
(F) Floodplain areas. The City Council may, 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 floodplain of any stream or drainage course. These floodplain areas shall be preserved from any and all destruction or damage resulting from clearing, grading or the dumping of earth, waste material or stumps, except at the discretion of the Planning and Zoning Commission.
(Prior Code, § Q-12-1012)