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<br />Weighted CN = 73 <br />21. PWCC has mapped that portion of the drainage as Mountain Brush <br />and Aspen which would be more indicative of Land Use 1, Forest <br />(see work map). PWCC will continue to use the more <br />conservative Land Use 3. <br />. 22. Please refer to response to Question 20. The curve number of <br />~~/JPnJ~- 69 as originally used was somewhat low (as compared to 73), <br />but for such a small drainage area, the change in ditch design <br />would be so insignificant that a resubmittal is not warranted. <br />23. Topsoil stockpile BB contains 1.5 acres of surface area. This <br />reduces the undisturbed area to 15.1 acres; therefore: <br />1.5 dC. x 70 CN = 205 <br />15.1 ac. x 30 CN = 453 <br />16.6 ac. 558 <br />Weighted CN = 558 = 34 <br />16.6 <br />The SEDCAD runs have been revised to reflect this revised <br />curve number. <br />24. Please see the revised design for Wadge Pit Diversion No. lA- <br />Temp. A SEDCAD watershed sketch is included with this <br />submittal. The diversion was redesigned based on the 2-year, <br />24-hour recurrence interval as per 4.05.3(2). Figure 38 in <br />NOAA Atlas was used to determine rainfall from that storm. <br />\ The specific lengths of the diversion that may require some <br />~\lr/ maintenance would be those areas below the sandstone bedrock <br />portion of the channel. The sketch through the deadhead spoil <br />,~ may require regrading from time to time. This stretch will be <br />~~~, short-lived (approximately two years) before it is mined <br />through and, therefore, does not warrant 600 feet of riprap. <br />The lowest portion of this diversion drains into the existing <br />channel. If a good stand of vegetation cannot be established <br />in this channel, other forms of erosion protection will be <br />warranted. <br />~25. Please see response to No. 24. <br />~'- 26. Please refer to the response to comment No. 17. <br />27. The main surface water diversion around the Wolf Creek Fill <br />was originally submitted and approved with Permit Revision <br />No.l, approved January 20, 1986. The fill area was <br />constructed adjacent to the box cut pit in the WC area. The <br />n fill does not approach the lower end of the riprap downdrain <br />\VI\N already constructed. This area, according to the presently <br />proposed backfilling and grading schedule, wouldn't be ready <br />5 <br />