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APPENDIX A— Mar�inal Runoff Calculations. Note, all engineering input was proved by the City of Roseville, 1 calculated depth, area, volume, and percentage (simple math - not engineeringJ. Given my attachment to this proposal and the preliminary nature of the calculations, I feel it would be unethical for me to certify these calculations. 1 would ask that the City Professional Engineers perform their own professional analysis. If this city wishes, I would be willing to hire an independent Professional Engineer to provide certified calculations to the city. The rainfall volume conforming to a 24hour/10year storm is 4.18", as verified and verbally confirmed by the City of Roseville Engineering staff on 7/15/16. The drainage area of this storm sewer system is 120 acres. The total amount of drainage is: 4.18" X 120acres = 41.8 acre f eet or 13,620,589 gallons The total impervious surface added in this assumption would be 3,250 ft^2. The marginal water flow from this development would be: 3,250 ftZx 4.18" = 13,585 ft^2 inches Convert this to acre ft: 13,585 f t2 inches *(1 f t\*� lacre 1= Q 026 acre f t \12in� 43,560ft2� Convert this to gallons: 325,851gallons 0.026acre f t*( )= 8,472 gallons lacreft The marginal contribution is 8,472 gallons. As a ratio: 8472 gallons 13,620,589 gallons 0.000621 = 0. 062% Looking at this another way, the storm sewer system is overstressed as follows: 13,620,589 = 1.28247 or 28.247% 13,620,589 — 3,000,000 Adding in the assumed marginal runoff from above: 13,620,589 + 8,472 = 1.28247 = 28.326% 13,620,589 — 3,000,0000 The marginal runoff adds the following overstress to the system: 1.28326 1.28247 1.00062 or 0.062% _ __ _ . _ _ _ ___ 1926 Gluek Lane Minor Subdivision request PF16-014 response to facts of denial 6�Page