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blanket and embankment face). The 1987 study did not, however, evaluate the dam embankment or its foundation. The 1985 slump was repaired over the next several years as a sliver fill with a less steep slope than the original surface (i.e., the intent was to flatten it to 2.5:1, H:V). This repair was documented in a set of drawings labeled "Repair of Slide Area on Backslope of Dam, Lone Cabin Reservoir" (Ute Engineering Revised As Built Feb. 1989, Final Submittal July 26, 1994). No other documents were found on file with the CDWR that indicate any geotechnical borings or soil testing performed on this dam. As noted previously in this application, a recent soil slump occurred in the summer of 2011. Jason P. Ward, Dam Safety Engineer for the Division of Water Resources Water Division 4, prepared an Engineer's Inspection Report (Appendix B) and letter dated August 18, 2011 following his site inspection of the slope failure on August 9. He described slope failure as a: "well-defined, arc-shaped scarp measured approximately 90 feet longitudinally along downstream slope. Slide material appears to have collapsed and consolidated. Scarp begins approximately 50 feet right of maximum section and ends approximately 135 feet left of spillway crest. Top of slide (scarp) located approximately 8 feet 3 inches below dam crest. Base of slide (toe) measured approximately 19 feet 7 inches below dam crest." In August of 2011, Buckhorn Geotech was retained by Lone Cabin Ditch and Reservoir Company to evaluate the cause of failure and to provide repair options for the Lone Cabin Dam to enable lifting of the current storage restriction. The results of this evaluation are provided in the Buckhorn Geotech draft report"Geotechnical and Design Report Lone Cabin Dam Rehabilitation, Division 4 Water District 40, Dam ID: 400404, Delta County, Colorado, Revised June, 2012" (Appendix A). Conceptual Repair Options In the June 2012 report, several repair options were offered on a conceptual basis. These options are described below. Advantages and disadvantages of each option are included. Option 1: Excavation of the slumped area to firm material, followed by placement of a graded filter material (chimney drain) that is connected to a suitable discharge point. This concept was later revised to include excavation of the slump area continuing down the face of the dam to include a new toe drain at the dam toe. The graded filter material would be laid directly on the face of the exposed firm subgrade and be covered with a minimum 5'thick layer of compacted embankment fill. Advantages of this option are that it uses conventional excavation equipment, and it is probably the quickest option to construct. Disadvantages are that water will need to be conveyed safely away from the embankment and that manufactured material must be imported. Option 2: Placement of an "impermeable" membrane on the upstream face of the dam. The membrane would need to be placed the full length of the dam face and extend from the crest 15