(A)   General requirements.
      (1)   The Plan Commission shall not recommend for approval any development or subdivision plat which does not make adequate provision for discharging storm or flood water using storm sewers, channels, detention basins or other approved conveyance systems. The storm water drainage system shall be separate and independent of any sanitary sewer system.
      (2)   Storm sewers, where required, shall be designed in accordance with the Town of Cloverdale’s Design Standards for Storm Water & Subsurface Drainage, and a copy of the design computations shall be submitted along with the plans. Inlets shall be provided so that surface water is not carried across or around any intersection, nor for a distance of more than 600 feet in the gutter and at locations where the encroachment of storm water into the street disrupts traffic. When calculations indicate that curb capacities are exceeded at a location, no further allowance shall be made for flow beyond that location and catch basins or inlets shall be installed to intercept flow. Surface water drainage patterns shall be shown for each and every lot and block.
   (B)   Nature of storm water facilities.
      (1)   Location. 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 development. Such drainage facilities shall be located in the street right-of-way where feasible, or in perpetual, unobstructed easements of the width specified in the Town of Cloverdale Design Standards for Stormwater and Subsurface Drainage, and shall be constructed in accordance with the Town’s Design and Construction Standards and specifications currently or hereafter adopted.
      (2)   Accessibility to public storm sewers. Where a public storm sewer of adequate size and capacity is accessible, the applicant shall install storm sewer facilities for the project and make a connection to the public storm sewer system. If no storm sewers of adequate size and capacity are located within a reasonable distance from the project, the applicant shall make provisions for the disposal of storm water, subject to the approval of the Town of Cloverdale.
      (3)   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 development. The developer shall determine the necessary size of the facility, based on the provisions of the required construction standards and specifications, assuming conditions of maximum potential watershed development permitted by the Zoning Ordinance.
      (4)   Effect on downstream drainage areas. The developer shall determine the effect of each proposed development on existing drainage facilities outside the area of the development. County drainage studies together with such other studies as may be available and appropriate may serve as a guide to needed improvements. Where it is anticipated that the additional runoff incident to the development will exceed the capacity of an existing downstream drainage facility, the Plan Commission may withhold secondary approval of the subdivision until provisions (such as a storage facility) has been made for the improvement of said potential condition in a manner approved by the Town of Cloverdale. No development shall be approved unless adequate drainage is provided to a drainage water course or facility having adequate capacity.
      (5)   Areas of poor drainage. Areas which are not in the flood plan, but contain soils which are subject to flooding, may be approved for development by the Plan Commission, provided that the developer fills the affected areas of said development to an elevation sufficient to place building sites and streets two feet above ponding levels subject to approval of the Indiana Department of Natural Resources, if applicable.
      (6)   Areas of high seasonal water tables. In areas characterized by soils having a high seasonal water table as determined by the Putnam County Soil and Water Conservation District, lots shall be limited to slab type construction, unless the Plan Commission determines that appropriate engineering techniques will be applied to alleviate the subsurface problem.
      (7)   Floodway area. If a development is proposed within the flood plain of a stream or watercourse, the floodway portion of the flood plain shall be preserved and not diminished in capacity by filing or obstruction, except as approved by the Indiana Department of Natural Resources in writing. No residential building site may be located within the floodway. Ordinances governing regulation of development within the flood plain of a stream or watercourse shall be applicable to the development.
      (8)   Floodway fringe areas. Where a subdivision is proposed within an area of the flood plain designated as a floodway fringe, the Plan Commission may approve such subdivision provided that: all streets are elevated sufficiently to be above the regulatory flood elevation; all lots for residential usage have a flood protection grade two feet above the regulatory flood elevation; where provided, water and sanitary sewer facilities are constructed to eliminate contamination of or by, flood water; and, approval to fill the area from the Natural Resources Plan Commission has been obtained in writing. Lands below the regulatory flood elevation shall not be used for computing the area requirement for any lot.
      (9)   Flood plain areas. Where a subdivision is proposed within an area of the flood plain for which floodway and floodway fringe designations have not been made, the Plan Commission shall not approve such a subdivision unless all streets are raised sufficiently to be above the regulatory flood elevation; all lots for residential usage have a flood protection grade of two feet above the regulatory flood elevation; where facilities are constructed to eliminate contamination of or by flood water; and filling to achieve the above will not raise the level of the regulatory flood elevation more than one-tenth of one foot for that reach of the stream. All filling in the flood plain must be approved in writing by the Indiana Natural Resources Plan Commission. Lands below the regulatory flood elevation shall not be used for computing the area replacement for any lot.
      (10)   Recording of plats in the flood plain floodway fringe. All final plats having within their boundaries areas whose elevation is below that of the regulatory flood boundary and elevation, as of the date the final plat is drawn, shall include, in detail, all of the information necessary to set out the location and nature of the regulatory flood boundaries upon the final plat for recording.
   (C)   Dedication of drainage easements.
      (1)   General requirements. Where a subdivision is traversed by a drainage course, drainage way, channel, or stream, a storm water easement or drainage right-of-way shall be provided granting or dedicating to the public or the Town of Cloverdale said area in an amount conforming substantially to the lines of such watercourse and of such width and construction or both as will be adequate for the purpose of both drainage and maintenance of the right-of-way. 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)   Drainage easements.
         (a)   Where topography or other conditions are such as to make impractical the inclusion of drainage facilities within street rights-of-way; perpetual unobstructed easements at least 15 fee in width for such drainage facilities shall be provided across property outside the right-of-way lines and with satisfactory access to the street. Easements shall be indicated on the plat. Drainage easements shall be carried from the street to a natural watercourse or to other drainage facilities.
         (b)   The applicant shall dedicate, either in fee or by drainage or conservation easement, land on both sides of existing watercourses of a width to be determined by the Plan Commission and, in the case of legal drains, the County Drainage Board.
         (c)   When a proposed drainage system will carry water across private land outside the subdivision, appropriate drainage rights must be secured by the developer and indicated on the plat.
         (d)   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. Such land or lands subject to periodic flooding shall not be included for computing the area requirement for any individual lot.
(Ord. 2011-07, passed  - - )