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-15- <br />C~ <br />condition for this embankment will occur immediately after construc- <br />tion when the maximum load is imposed on the relatively soft founda- <br />tion soils, and there has not been sufficient time to allow consoli- <br />dation of the soils below the embankment. After consolidation occurs, <br />the underlying clays will increase in strength and the factors of <br />safety against a sliding failure will increase. No analysis of satura- <br />ted embankment conditions was made as part of this investigation. <br />The maximum operating head will range from 8 to 10 feet for the <br />expected life of this embankment. Anticipated construction includes <br />the earth embankment for the dam, followed shortly by construction <br />of a higher and much larger embankment immediately downstream of the <br />dam for use as a haul road. Considering the length of seepage path, <br />• the relatively low head and the highly impervious nature of the clay <br />fills for dam construction, it may not be possible to develop steady <br />state seepage conditions within the currently planned life expectancy <br />of the structure. The rapid drawdown condition was also not analyzed. <br />T}~e reason for this neglecting the rapid drawdown conditions is that <br />there will never be water in the pond area for a long enough period <br />to saturate the clays to a high enough level to make a drawdown type <br />analyses meaningful. When design floods occur the water will be <br />discharged through the outlet works in a very short period of time <br />ranging from 26 to 35 hours. Water loss below the permanent pool level <br />will essentially be by evaporation. The maximum head differential <br />will be on the order of 8 feet for these conditions. We do not believe <br />rapid drawdown of the upstream face is a significant design consideration. <br /> <br />