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PERMIT #: M -1977 -141 <br />INSPECTOR'S INITIALS: MAC <br />INSPECTION DATE: October 22, 2013 <br />OBSERVATIONS <br />The inspection was conducted by Michael Cunningham of the Division of Reclamation, Mining and Safety <br />(Division). Connie Davis of Aggregate Industries was present for the inspection. In addition, Ernst Strenge, Ron <br />Stewart, Mel Stonebraker, Denny Morris, Dave Hoerath, David Hirt and Kristine Obendorf of Boulder County <br />were also present for the inspection. The Lyons Quarry is located approximately 3 miles southwest of Lyons, <br />Colorado on Highway 7. The site is permitted for 71 acres and the post- mining land use is rangeland. <br />The inspection was conducted at the request of Boulder County, the current landowner of the property where <br />the Lyons Quarry is located. The request for an inspection was made in response to the flooding of the St. <br />Wain Creek which occurred in September 2013. The purpose of the inspection was to assess impacts from the <br />flood and discuss potential mitigation measures for any damage that occurred. The South St. Wain Creek flows <br />west to east along the northern edge of the Lyons Quarry. During the flood event the St. Wain Creek <br />overtopped the southern bank and flowed through a portion of the Lyons Quarry. The portion of the quarry <br />which was impacted by flooding is a staging area primarily used for equipment storage and product stockpiles. <br />The impacted area lies at the northern extent of the quarry and is comprised of a level area that is surfaced <br />with crusher fines; the area is approximately 2,000 feet long and 350 feet wide. The Lyons Quarry is in the first <br />five year term of temporary cessation, which was approved on February 16, 2011. As a result, the site was not <br />active at the time flooding occurred and impacts to equipment and product stockpiles were minimal. <br />At the time of the inspection a portion of the St. Wain Creek had returned to its pre -flood channel. However, a <br />segment of the creek was still flowing through the east side of the quarry between the shop building and the <br />scale house. Prior to the flood, the St. Wain Creek was flowing approximately 250 feet north of the scale <br />house. During the flood, the�St. Wain Creek breached the southern bank at the northwest corner of the <br />storage /processing yard and, flowed in braided channels across the yard. A significant amount of erosion <br />occurred as a result of flooding. The Division observed erosion channels across the storage /processing yard <br />that ranged between one toIfive feet in depth. In addition to erosion, the Division observed significant amount <br />of deposition across the site The material which was deposited consisted of silt, sand, cobble stone and large <br />boulders; the depth of this material ranged between one to three feet deep. In addition, there was a <br />substantial amount of organic debris deposited on site including whole trees. <br />'During the flood a portion of the St. Wain was flowing in the historic channel located along the base of the <br />north side of the mountain where quarrying is occurring. Boulder County is considering relocating the St. Wain <br />Creek to the historic channel in order to minimize the potential impact of future flood events on Highway 7. <br />Relocating the St. Wain Creek to the historic channel would create a 400 ft. buffer between the creek and <br />Highway 7. If the St. Wain Creek is relocated to the historic channel, the Operator would need to revise the <br />Reclamation Plan to reflect this change. As mentioned earlier in this report, a portion of the St. Wain Creek is <br />flowing between the shop building and the scale house. If the St. Wain Creek will remain in its current <br />location,'then the Operator�will need to file a Technical Revision to update the Reclamation Plan; additional <br />approvals maybe required from other State and Federal agencies. If the Operator returns the creek to its pre - <br />flood location, then no permitting is required. The Reclamation Plan specifies that the storage /processing area <br />will be reclaimed to rangeland. The Operator will need to review the Reclamation Plan to determine if the <br />post- mining land use can still be achieved for the area that was impacted by flooding. If the Operator <br />determines that the post- mining land use cannot be achieved, then the Reclamation Plan will need to be <br />revised accordingly. f <br />I <br />i <br />I' Page 2 of 9 <br />M <br />