Laserfiche WebLink
Page 2 of 5 <br />NECC: Page 2.05 -44 has been revised to include discussions of the temporary stockpile approved <br />by MR -117. Also, reference to Exhibit 42 was changed to Exhibit 43. No content has changed <br />in the report, therefore, only the cover page will be supplied. <br />Division: Response is sufficient. <br />5. NECC must provide a plan for controlling runoff, particularly energy dissipation, once it flows <br />through ditch D49 and onto the Parks and Wildlife property. Also, a field inspection from early <br />May 2012 reveals that the drainage culvert on CPW's property which would relieve the runoff <br />from ditch D49 has been buried. Finally, the Division requests that NECC contact Colorado <br />Parks and Wildlife (CPW) regarding the discharge point of ditch D49. <br />NECC: A temporary use agreement has been submitted to CPW to address energy dissipation of <br />D49 once it leaves NECC property. The plan includes extending D49 by approximately 60', <br />plating it with 15" riprap and then discharging into a 36" culvert, C85. The proposed <br />arrangement can be seen on Map 14 and ditch and culvert design shown on Tables 20 and 21, <br />respectively. CPW approval will be submitted to DRMS once it is obtained. <br />Division: Per Table 20, the peak discharge in Ditch 49 (12 %) is 72.33 cfs. If this flows into culvert <br />C85, why is the flow for C85 in Table 21 only 33.51 cfs? <br />NECC needs to submit a copy of the signed (not the draft) temporary use agreement, for <br />insertion into the Right of Entry (Rule 2.03.6) section of the New Elk PAP. Preferably, this will <br />be done before the Division decision on this technical revision. <br />6. The ditch D49 SEDCAD printout is unclear. In the time of concentration details (page EXH <br />19(22) -49), there are two times listed for SWS #2 for Structure #2: 0.055 hour and 0.377 hour. <br />Please explain. It would be very useful (but not necessary) to provide a schematic and /or map <br />showing structures, sub - watersheds, and flow paths for D49 and other ditches. <br />NECC: There are two subwatersheds for Structure #2. One subwatershed is associated with the <br />upland area, the other is associated with the disturbed are that is contributing flow to the <br />channel. The large majority of the runoff in ditch D49 is from the upland area, however, there is <br />a small portion of runoff that will be generated from the berm that will be constructed between <br />D49 and the various portions of the collection ditch in the outslope of the waste pile. <br />Division: This portion of the model is still unclear. The NECC explanation does not address why <br />there are two times listed for SWS 92. Furthermore, the Subwatershed Hydrology Detail table <br />lists three SWSs, not two. <br />7. The location where ditch D49 would originate was inspected. Please provide more details on <br />the design of the upper end of this ditch to determine if it is sufficient to prevent flow down <br />