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TABLE 4.6-28 (continued) <br />• Ponding Adjustment Factor <br />Since our spoil areas have such a high infilTration rate and virtually no runoff, <br />we have deTermined that all of our spoil areas act as a ponding effect for the <br />watershed area. The area is reduced considerably in the central part of the watershed <br />due to reclamation in year four. <br />Acres in the central part of the watershed (ponding area = 63.26 ac.) <br />Ponding Area - 63.26 ac. X 100°6 = 6.6°,6. <br />- 961.01 ac. <br />From Table E-3 by interpolation for a storm frequency of 10 years. <br />Factor = 0.65 + (6.7-6.6) (0.68-0.65) = 0.65. <br />6.7-5.0 <br />Acres in the upper part of The watershed (Ponding area = 57.04 ac.) <br />• % Ponding Area - 57.04 oc. X 100°b = 5.9%. <br />- 961.01 oc. <br />From Table E-4 by interpolation for a storm frequency of 10 years. <br />Factor = .80 + (6 7-5.9) (0.62-0.60) = 0.61. <br />6.7-5.~ <br />Since we have two conditions existing for Ponding Areas, we will find a weighted <br />average factor the areas according to acres. <br />Weighted Ponding Factor = (63.26 ac)(0.65)+(57.04 ac)(0.81) = 0.73. <br />.6+ .4 ac. <br />Peak Discharge = 60.4 cfs x 0.73 = 44.1 cfs. <br />J <br />Revised 7-81 4.6-89 <br />