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<br />certification for Pond #2 is contained in Appendix Q. <br />Pond #3 was constructed with Blackhall Loamy Fine Sand. The <br />material was handled in 3-6" lifts and compacted with a D9 <br />Caterpillar tractor and finish graded with a 14G Caterpillar motor <br />grader on both the slopes and the top of the embankment. Upstream <br />and downstream slopes were maintained at 3H:1V for both structures. <br />Certification for Pond #3 was conveyed to MLRB in early February, <br />1981 and is contained in Appendix Q. <br />Pond #2 drainage area is 35.38 acres. A SEDCAD+ run is <br />provided to Appendix Q which documents the following information. <br />5-year 24-hour event = 1.4 inches; 1.28 acre-feet runoff <br />10-year 24-hour event = 1.60 inches; 1.68 acre-feet runoff <br />• 25-year 24-hour event = 2.00 inches; 2.58 acre-feet runoff <br />10 year Maximum Sediment Volume = 0.21 acre-feet <br />Total Volume to Emergency Spillway = 16.2 acre-feet <br />Sediment volumes were derived using the Revised Universal Soil Loss <br />Equation (RUBLE). <br />The Pond #3 drainage area is 3.5 acres and according to <br />Procedures for Determining Peak Flows in Colorado by the Soil <br />Conservation Service (USDA, March, 1977) the key factors for this <br />pond are as follows: <br />10-year 24-hour event = 1.60 inches; 0.19 acre-feet runoff <br />25-year 24-hour event = 2.00 inches; 0.28 acre-feet runoff <br />3 year Maximum Sediment Volume = 0.35 acre-feet <br />Total Volume to Emergency Spillway = 0.35 + 0.19 = 0.54 ac-ft <br />• <br />- 3 9 - Revised 11/29/94 <br />