28-14 Amend Chp. 1339 Storm Water Mgmt

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(2) Each facility's storage capacity shall be no less than 1,800 cubic feet of dewatering zone area per acre of total contributing drainage area and 1,000 cubic feet per disturbed acre of sediment storage zone area. The storage volume will be measured from the bottom of the basin to the top of the primary (principal) spillway. (3) Permanent storm water management ponds that are designed to trap sediment during construction shall be designed to provide for a slow re- lease of sediment -laden water. The draw down time shall be at least 48 hours, or meet the criteria in the Ohio Rainwater and Land Develop- ment manual, whichever is more stringent. (4) The design configuration between inlet(s) and the outlet of settling ponds must provide at least two units of length for each one unit of width (> 2:1 length -to -width ratio); a length to width ratio of 4:1 is rec- ommended. (S) The depth of the dewatering zone of the sediment settling pond must be less than or equal to five feet. (6) Sediment must be removed from the sediment settling ponds when the design capacity has been reduced by 40 percent. (7) Public safety, especially as it relates to children, must be considered in the design. Alternative sediment controls must be used where site limi- tations would preclude a safe design. (8) Temporary sediment settling ponds will not be constructed in any stream channel. (1) Storm Sewer Inlet Protection: (1) All stone sewer inlets that accept water runoff from the development area shall be protected so that sediment -laden water will not enter the stone sewer, unless the storm drain system drains to a sediment settling pond and is exempted in writing by the city engineer. In areas where construction will be ongoing, such as subdivisions, the storm sewer protection shall be maintained until all up slope areas reach final stabi- lization, as determined by the city engineer. (2) All inlets receiving runoff from drainage areas of one or more acres will require a sediment settling pond. (3) At the end of this period the site owner shall hydraulically clean the storm sewers to the satisfaction of the city engineer. All sediments shall be removed from the system and shall not be flushed downstream. (m) Storm Sewer and Other Drainage Outlets: All storm sewers, footer drains, roof gutter drains and all other drains will be outletted at the bottom of the slope. The slope below the outlet will be able to control the water being drained through the storm sewer or other drains without causing erosion of the stream or channel banks or channel bottom or other areas that the water is outletted on. (n) Working Near, Or Crossing Streams and Wetlands: 44