Laserfiche WebLink
EXHIBIT A: CHAPTER 928 <br />practicable leave native soil undisturbed and protect from compaction during <br />construction. Except for areas that will be covered by impervious surface or have <br />been incorporated into an SCM, the soil moisture -holding capacity of areas that <br />have been cleared and graded must be restored to that of the original, undisturbed <br />soil to the maximum extent practicable. Areas that have been compacted or had <br />the topsoil or duff layer removed should be amended using the following steps: 1. <br />Till subsoil to a depth of 15-18 inches, 2. Incorporate compost through top 12 <br />inches, 3. Replace with stockpiled site or imported suitable topsoil to a minimum <br />depth of 4 inches. <br />B. Stormwater Conveyance Design Criteria: All SCMs shall be designed to convey <br />stormwater to allow for the maximum removal of pollutants and reduction in flow <br />velocities. This shall include but not be limited to: <br />Surface water protection: The City Engineer may allow modification to streams, <br />rivers, lakes, wetlands or other surface waters only if the applicant shows proof of <br />compliance with all appropriate permits from the Ohio EPA, the U.S. Army <br />Corps, and other applicable federal, state, and local agencies as required in <br />Section 928.07 of this regulation, and the activity is in compliance with Section <br />927 Erosion and Sediment Control and Section 926 Riparian Setbacks and <br />Wetland Setbacks, all as determined by the City Engineer. At a minimum, stream <br />relocation designs must show how the project will minimize changes to the <br />vertical stability, floodplain form, channel form, and habitat of upstream and <br />downstream channels on and off the property. <br />2. Off-site stormwater discharges: Off-site stormwater runoff that discharges to or <br />across the applicant's development site shall be conveyed through the stormwater <br />conveyance system planned for the development site at its existing peak flow <br />rates during each design storm. Off-site flows shall be diverted around <br />stormwater quality control facilities or, if this is not possible, the stormwater <br />quality control facility shall be sized to treat the off- site flow. Comprehensive <br />Stormwater Management Plans will not be approved until it is demonstrated to the <br />satisfaction of the City Engineer that off-site runoff will be adequately conveyed <br />through the development site in a manner that does not exacerbate upstream or <br />downstream flooding and erosion. <br />Sheet flow: The site shall be graded in a manner that maintains sheet flow over as <br />large an area as possible. The maximum area of sheet flow shall be determined <br />based on the slope, the uniformity of site grading, and the use of easements or <br />other legally -binding mechanisms that prohibit re -grading and/or the placement of <br />structures within sheet flow areas. In no case shall the sheet flow length be longer <br />than 300 feet, nor shall a sheet flow area exceed 1.5 acres. Flow shall be directed <br />into an open channel, storm sewer, or other SCMs from areas too long and/or too <br />large to maintain sheet flow, all as determined by the City Engineer. <br />4. Open channels: Unless otherwise allowed by the City Engineer, drainage tributary <br />