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. Fall 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />original survey location using global positional system (GPS) coordinates. In most instances, the <br />second survey location is a reasonable representation of the original. However, the lack of <br />specifically set markers during the original survey accounts for much of the differences <br />represented in the presented data. <br />3.3 Monument Dam/Minnesota Reservoir Baseline Data <br />Beginning in 2006, numerous monitoring stations were established on Monument Dam and at <br />strategic locations around Minnesota Reservoir as a means to collect baseline information about <br />water levels and potential surface/subsurface movement. Monitoring locations include three <br />historic standpipe piezometers, four boring locations each with three nested piezometers, two <br />inclinometer locations (one on the dam and one in the landslide area south of the dam), and <br />numerous survey mirrors for evaluation of surface movement on and near the dam. Many of <br />these locations have been monitored monthly from July 2006 while others were added to the <br />monitoring network during this past year. Information collected from each of these monitoring <br />locations is graphically illustrated in the several figures provided in Appendix D. <br />In addition, MCC has an obligation to conduct annual aerial photographic surveys of the <br />landslides located north and south of Minnesota Reservoir, using July 2004 photographs as a <br />baseline reference. This report includes as Appendix E the July 2004 baseline photograph (Map <br />E-1) as well as a photograph of the same area taken in September 2008 (Map E-2). A <br />comparison of the two photographs shows there to be no observable difference in those slide <br />areas with the obvious exception of the earthwork conducted on the south side of Monument <br />Dam where considerable materials were removed to buttress the downstream portion of the dam <br />and readjust/rebalance the toe load of the landslide. As of the September 2008 photograph, no E- <br />seam mining had occurred in the South of Divide Mining Area (the mining area nearest to <br />Minnesota Reservoir and Monument Dam). <br />Of note in review of Map E-2 is a green circular area located south of the excavation on the south <br />side of Monument Dam. This obvious feature is within the most recently active portion of a <br />0 much larger landslide area to the south of Monument Dam and Minnesota Reservoir that was <br />831-032.790 Wright Water Engineers, Inc. Page 12 <br />December 2008