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EXHIBIT A: EXISTING CHAPTER 927 Storm Water Management and Urban 66M Sediment Pollution Abatement Systems 927.06 (e) The rainfall intensity shall be based on Table 1 entitled "Standard Rainfall Intensity Duration Table". (f) If the volume of runoff is greater after development than before development, the peak rate of runoff shall be reduced. The critical storm shall be determined by the percent increase in runoff volume. The peak rate of runoff from the critical storm and all more frequent storms, shall be no greater than ninety percent (90%) of the peak rate of runoff from the one year storm occurring before any development. Runoff rates from less frequent storms (longer return periods) than the critical storm shall satisfy the requirements in Paragraph (b) of this Section. (g) The critical storm for a specific development area is determined as follows: (1) Determine the total volume of runoff from a twenty -four-hour one year frequency storm, occurring on the development area based on the difference between after development and ninety percent (90%) of before any development. (2) From the volumes in Paragraph (c) of this Section, determine the percent of increase in volume of runoff due to development and, using this percentage, select the critical storm from the following table: If the percentage increase in volume of runoff is: The "critical storm" Equal to or and for discharge Greater than Less than limitation will be: 0 10 1 Year 10 20 2 Years 20 50 5 Years 50 100 10 Years 100 250 25 Years 250 500 50 Years 500 --- 100 Years (h) The minimum storage volume for the stormwater retention system shall be calculate following the requirements of subsections (a) through (g) above. However, in no case shall the required storage volume be less than the total proposed hardsurface area of the site times two inches. Hard surface areas shall include roof areas, concrete areas, asphalt areas, brick areas, stone paver areas, and other similar areas as determined by the City Engineer. (i) The requirements shall be satisfied at each location where runoff leaves the development area. The runoff rates and volumes shall be considered for both the conditions before development and after development at each of these locations. 0) To ensure the continued functioning of stormwater control structures, the following information shall be identified to the satisfaction of the City Engineer. (1)The person or entity responsible for continued maintenance of the stormwater control structure and the mechanism establishing responsibility; (2)Maintenance requirements and Schedules; and (3)Permanent access and access easements required to perform inspection and maintenance of stormwater control structures and stormwater conveyance systems if easements are required by City. The minimum size of an easement shall be approved by the City Engineer.