Laserfiche WebLink
<br />Woodward.C1yde Consultants . <br /> <br />:",_ ('"'t. (' {'Of <br />i.0;J;J <br /> <br />4396. The profile drawing (Figure 2) indicates that the inter- <br /> <br />section of the active conservation and joint use reservoir <br /> <br />water levels with natural ground surface occurs around Stations <br /> <br />l <br /> <br />229 and 230. The profile plots available to us may not <br /> <br /> <br />accurately show the ground surface. It i~likelY that the <br /> <br /> <br />foundation zone downstream from the da/a.round Stations 230 and <br /> <br /> <br />232 will remain saturated to grOUnd~,~~e believe that <br /> <br /> <br />short term high water levels wi~reate active~eady-state <br /> <br /> <br />seepage flow conditions at th,Ltoe of the dam. This <br /> <br /> <br />distribution of hydraulic graa~ts~alOng the seepage paths <br /> <br /> <br />will not be uniform (at the ~~alUe) since foundation <br /> <br /> <br />soil permeabilities vary. A large ~~ion of the loss in total <br /> <br /> <br />head will be near the ~~cau~ above average <br /> <br /> <br />hydraulic exit gradient~ ~ ~ <br /> <br /> <br />Average hydraulic gr~ients are shown in Figure 8 for two <br /> <br /> <br />cross sections, St~ions 231~~ 224. The maximum average <br /> <br /> <br />---gradient-a-t--(-a!:Zd.J-lcL_i-S-~l;. -unde-r- maximum_water_surtace__ - -, <br /> <br /> <br />conditions. C'onside,Gble additional safety exists at Station <br /> <br /> <br />224 since.....natu'~~ level is about 15 feet above the <br /> <br /> <br />expect~~~face (saturation surface) within the soil and <br /> <br /> <br />also~use the~rJsulting partially saturated zone in the <br /> <br /> <br />foundati~pstre~ and downstream of the embankment will <br /> <br />~v/ <br />impede develoPment of steady-state saturation flow conditions <br /> <br />. <br /> <br />t <br /> <br />during the brief periods that high water is against the <br /> <br />. <br /> <br />embankment. In addition, the higher downstream ground surface <br /> <br />- 24 - <br /> <br />t <br /> <br />II <br />