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' A 25' buffer strip adjacent to the highway has been left undisturbed to create a visua barrier and <br /> minimize sediment production and transport from mining operations to the CDOT ri t-of-way. <br /> ' This buffer strip is a stipulation per the current reclamation plan. <br /> Earthen berms, with heights of 10 to 15 feet, have been constructed near the 25-foot buffer strip <br /> ' to minimized rocks from leaving the highwall area and rolling toward the CDOT rig it-of-way. <br /> The berms also serve to minimize visual impacts of the mining operation. The berm are fairly <br /> well vegetated and stable. <br /> ' The access (roadway) from the highwall area to the top of the stockpile is a fairly step accent, <br /> with slopes averaging 10 to 20 percent. Vegetative growth on the roadway is almost nonexistent <br /> ' due to the coarse materials forming the roadbed. Erosion activity on the roadway appears to be <br /> minimal. However, due to the steep slope and bare ground,the potential for future erosion and <br /> headcutting of the roadway is likely. <br /> ' A steep wash dissects the highwall area from the stockpile. The wash area has large oulders <br /> (greater than 3 to 4 feet in diameter rock) which demonstrate the flooding potential o the area <br /> during intense thunderstorms during the summer months. The wash then continues down the <br /> ' slope to a flat area near the bottom of the stockpile. Runoff from this wash then travels under the <br /> highway, via a 36-inch CMP culvert, and then southerly to East Creek. No serious headcutting <br /> was noticed where the roadway crosses the wash near the top. However, it is believe the potential <br /> exists for headcutting of the roadway and result in failure of the roadway to provide f urther <br /> access. <br /> ' The existing 18-inch CMP culvert crossing the highway near the entrance to the quarry is mostly <br /> filled with sediment. The primary purpose of this culvert is to convey irrigation water from the <br /> upper wash area to downstream pasture areas between the highway and East Creek. <br /> ' SECTION 4.0 RECOMMENDATIONS <br /> ' The purpose of the revised reclamation plan is to incorporate the following rehabilitation <br /> measures as mining operations are terminated. Per the mining permit,the site is to be specifically <br /> restored for wildlife habitat. Additionally,the area is to be reclaimed such that the permit area is <br /> ' returned as much as possible to the existing conditions of the site, especially in terms of <br /> vegetation for wildlife forage and cover, and also to maintain historic drainage patte s and flows. <br /> Similarly,the aesthetics will be enhanced per feasible measures. <br /> ' Specific items to address for final reclamation of this rock quarry include the follow' g: <br /> ' Access Roadway and Hau!Road <br /> Construct waterbars across the access road, from the bottom of the highwall area to flie top of the <br /> ' stockpile area. The waterbars shall be constructed about 50 feet(horizontally) apart d be about <br /> 18 inches tall. See the detail for constructed waterbars. <br /> ' Place large,native rocks (6"—36" longest dimension)along the top slope from the a lge of the <br /> access road. The large rocks will serve as a cutoff wall to minimize headcutting. <br /> ' 5 <br />