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2.05 APPLICATION FOR PERMIT FOR SURFACE OR UNDERGROUND MINING ACTIVITIES - <br />MINIMUM REQUIREMENTS FOR OPERATION AND RECLAMATION PLANS. <br />Leaf calculated the 10-year, 24-hour precipitation event and <br />concluded that it would generate 2.2 inches of precipitation at <br />Paonia. Using this value and a recharge requirement of 2.75 <br />inches, a direct runoff of approximately 0.46 inch (0.09 acre- <br />foot/acre) would be predictable. This represents a four-fold <br />increase in storm runoff potential, compared with runoff of <br />approximately 0.15 inch (0.01 acre-foot/acre) for the permit <br />area prior to disturbance. See "Drainage Plan and Design and <br />Location of Phase I Sediment Retention Ponds at Orchard Valley <br />Mine", Ponds, Impoundments and Dams Appendix in Volume 8A for <br />theory used in determining these values. In summary, predicted <br />runoff quantities are: <br />Disturbed watershed 0.04 ac-ft/acre <br />Undisturbed watershed 0.01 ac-ft/acre <br />Assuming recharge requirements of: <br />Disturbed watershed R~ = 2.75 inches <br />_ Undisturbed watershed R~ = 4.75 inches <br /> <br />Permit Renewal <br />/lN-o 4 (Y/4~a y) <br />M2-1o6 <br />- 19 - <br />01/03 <br />