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Suppose a storm produced rainfall of 3. 6 inches <br /> over the site. Volume of runoff would be: <br /> [ ( 0.75) ( 56, 650/43 , 560) + (0.20) ( 39 ,000/43 , 560) + <br /> 1 .0 ( 4 , 950/43 , 560) 7 <br /> X 3 .6 in/12 = 0.38 Ac . Ft . <br /> = 16, 570 C.F . <br /> subtracting out pond storage of 14 , 200 C.F . leaves <br /> an overflow of 2 ,370 C.F . This is less than one- <br /> third of the existing runoff for the 10 year - 24 <br /> hour storm. <br /> This example demonstrates that a 200% safety <br /> factor is not necessary to protect adjacent areas <br /> from flooding due to the increased runoff from <br /> this project . <br /> 4 . From the University of California Soil Survey <br /> entitled "Soils of San Joaquin County , <br /> California" , the predominant soil type at this <br /> vicinity is shown to be San Joaquin Loam, . and is <br /> rated as "good" for both surface and subsurface <br /> drainage. This backs up our assumptions regarding <br /> existing runoff coefficients , and the fact that <br /> existing runoff does not adversely affect the <br /> area . This type of soil will also percolate well , <br /> which will lessen the impact of back-to-back <br /> storms on the pond storage . <br /> My conclusion from this reasoning is that <br /> requiring storage volume of 200% of the total <br /> runoff is not reasonable for this project , given <br /> the type of project it is and the existing <br /> drainage conditions . Providing an additional <br /> 0 ,000 + C.F . of storage volume would severely/ <br /> impact the project and my client is already <br /> required to reserve 24 ,000 S .F . of surface area <br /> for replacement leach field area . <br /> Please review this proposal and reply with the County ' s <br /> decision as soon as possible . Thank you for your <br /> consideration of this request . <br /> Sincerely , <br /> STEVEN E . PECHIN <br /> President <br /> cc : Earlene Lund <br />