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. . John W. Raid Page 4. July 23, 1973 At the time I was last in Marble (July 3, 1973) a route was being staked for a new road across the east part of this area and down to the Crystal River east of Beaver Lake. I am most concerned that past mistakes might be repeated in this construction. The minimum requirements for constructing a stable roadway would include: (1) removal of colluvium and strongly weathered shale in both cut and fill areas, and in fill areas the bedrock surface should be benched to prevent failure along the inclined fill-bedrock interface; (2) all embankments should be constructed as engineered fill with strict moisture and density control; (3) on many of the steeper slopes a stable embankment slope will not meet the natural slope in a reasonable distance, so retaining of some type will be re- quired; (4) both seepage and surface water will have to be controlled to prevent unwanted saturation of embankments and downslope development a~as. The entire road construction should be done under supervision .of a Soils Engineer with in- put as needed from an Engineering Geologist. 2) Development activity on the west slope of Mt. Daly. I also inspected proposed development areas on the west slopes of Mt. Daly in Condominium Filing No.1, and the Village site which is higher upslope on the west slope of the Mt. Daly area. Construction is going on at two sites at this location, a condominium complex on lot No. 17, and a lodge near the north end of the Village area. Active landslid- ing has occurred in the past and continues on the east side of Carbonate Creek. Most of the active landslide area is in green belt, but five condominium lots were removed as a result of our continuing dialogue with the developer and their con- sultants. The subject of active sliding in the green belt area adjacent to Car- bonate Creek will be discussed in a subsequent section of this memorandum. The west slope development areas of Mt. Daly are in general located on much gen- tler slopes, and stability problems are related more to control of surface runoff and to massive spring seepage through the surficial deposits. It was noted that the construction on lot No. 17 resulted in a total disturbance of the surface and removal of all but a very few trees. It is obvious that development of this in- tensity will have to be carefully controlled and staged to prevent intolerable hydrologic and aesthetic impacts. Construction at the Lodge site is at this stage less alarming than that on lot 17, but eventually the Village area is conceived as including approximately 40 acres of intensive development. Massive seepage con- tinues'through much of this area and surface prainage in the vicinity of lot 17 has been diverted down the road and overland toward Carbonate Creek. There have been reports of serious erosion on the ski runs so I also looked into this. I thoug~that in general the revegetation along the lift line and ski runs had been very successful. As you can see from the slides and color prints, there was severe erosion on a steep escarpment of the southern most sk~ run which also caused concentration of runoff that did additional erosion and deposition down the remainder of that slope.' The ski company people were working on the problem by installing larger erosion control structures and by mulching and seeding. I have no doubt that this problem can and will be solved before it become overly serious.