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<br />. <br /> <br />consist of installation of two observation wells, two inclinometers, <br />and construction of filter drains at the existing seepage areas. <br />Detailed information concerning the monitoring program is provided <br />in Appendix D. <br />The cost for installing the test wells and inclinometers would <br />probably be about $25,000. An additional $5,000 would probably be <br />required for construction of the filter drains. However, the addi- <br />tional cost for filter drains would not be incurred if rock-fill and <br />embankment is placed at the downstream slope to increase dam stability <br />and raise the dam crest. Inclinometer measurement and interpretation <br />of results should be done by a skilled technician or geotechnical <br />engineer. The annual cost of the monitoring program is estimated to <br />be about $10,000. <br /> <br />. <br /> <br />Alternate A <br /> <br /> <br />As described in the flood hydrology report provided in Appendix C, <br /> <br /> <br />the one-half probable maximum flood can be safely passed by the existing <br /> <br /> <br />dam and spillway if the initial reservoir storage content is less than <br /> <br /> <br />40,000 acre-feet (elevation 9437.3). Under Alternate A, the reservoir <br /> <br /> <br />would be held below 40,000 acre-feet during the period of July through <br /> <br /> <br />October when the one-half probable maximum flood could potentially <br /> <br /> <br />occur. The reservoir could be held at a higher level during the <br /> <br /> <br />remainder of the year. Since the stability of the dam is not well <br /> <br /> <br />defined at the present time, a monitoring program of the dam would <br /> <br /> <br />be included under Alternate A to provide additional information. As <br /> <br /> <br />the reservoir water level increases to 40,000 acre-feet and additional <br /> <br /> <br />water is stored, the monitoring program would be used to warn of <br /> <br /> <br />hazardous conditions. The monitoring program would consist of measuring <br /> <br /> <br />water levels in the existing test holes, measuring seepage near the <br /> <br /> <br />dam toe, and monitoring the north abutment stability. If hazardous <br /> <br /> <br />conditions are found to exist, storage in the reservoir would be <br /> <br /> <br />restricted to a safe level and an analysis would be made to determine <br /> <br />what rehabilitation measures should be taken. Details concerning the <br /> <br />, <br /> <br />-44- <br />