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-3- <br />back-floods very slightly onto the pasture bordering the south edge of the <br />inlet. The applicant has suggested they could/would assist the ditch ownership <br />removing driftwood in the future and possibly provide discounted materials to <br />maintain and/or repair damage to the inlet due to erosion from the river. <br />• Concerning the issue that the Yampa River could become re-routed <br />through the pond: As stated above in #2 , "Spring 2008 High Flow <br />levels in the Yampa River at the site (the highest observed in recent <br />times) had no affect to the Deep Cut Ditch inlet and did not flood any <br />part of the site south of the ditch inlet. The Ditch Ownership made <br />statements at Moffat County Hearings that "the last time water <br />submerged the Deep Cut Ditch was in 1983". The flooding occurred <br />mostly along and to the west of the Deep Cut Ditch as it provided the <br />preferable flow pathway to the over- banking river waters to the <br />adjacent floodplains on or below the 6200 foot elevation level. <br />• Historic air photos, the topographic map and site observations show <br />that the Yampa River, during High Flow water levels, prefers to chute <br />through an old channel and over the opposite river meander loop <br />located on the north side of river across from ditch inlet. <br />• Occasional repairs to the riverbank can always be made in conjunction <br />with the U.S. Array COE. The COE has physically inspected the site <br />(5/6/08 - Mr. Nathan Green) and has made no comments about any <br />possible concerns about "pond capture" or concerns that the river may <br />re-rout itself through the future pond. <br />• Any "extreme" flooding onto the excavation areas of the site would be <br />a "typical over-banking, low velocity back (rising) flood". The back <br />flooding onto the site would also be limited (as seen this spring 2008) <br />due to the local topography (high ground to the east and northeast) and <br />the current north bank chute preference of the Yampa River during <br />periods of high flow. Any slow rising, low velocity back flooding may <br />saturate a particular topsoil stockpile but erosion and offsite sail <br />transport/migration would be very limited and mitigated by vegetation, <br />silt fences etc ... Further, the + 30 acre pond area, with an estimated <br />average 4 foot invert (average pond water levels would be +/- 6196) <br />would provide over 100 acre feet of storage capacity to the floodplain <br />for any "extreme high water event" that may occur. <br />4. CDPHE Stormwater Permit will be revised and modified to allow for <br />discharge of process (dewatering) waters to assist in the site operations and <br />enable groundwater to be discharged offsite to the river (ditch inlet). This <br />should (will) also eliminate the "groundwater drawdown concerns" from the <br />ditch ownership. As stated in #1 above: "Until the SW permit is revised <br />allowing dewatering to the Yampa River, the site will dewater to a sediment