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I I I I I I I I I I I I I I I I I I I No toe drain Is required at the saddle dam as seepage has not been noted to be a problem In the past. The head against the dam at normal pool wlil only be approximately 5 feet and would not be expected to produce seepage through the clay flil and clay foundation present at the saddle dam. 3. Slope Protection. The upstream slope wlil be protected with a twenty-four Inch (24") layer of rlprap with a nine-inch (9") layer of rlprap bedding. The rlprap sizing will range from eighteen Inches (18") to three Inches (3"), and the bedding from three Inches (3") to sand size. If present costs of the rehablilta- tlon become a problem, the thickness of the rlprap layer. could be reduced to 18 Inches to reduce the cost. However, more long term maintenance can be expected If a thinner layer Is utlilzed. The downstream slope and any other fill or excavation areas, such as In the splllway, wlll be protected by applying topsoil and grass seeding. Areas of high erosion potential, such as In the outlet channel and around the splllway control section, will be protected with rlprap and bedding of the same size described for the dam slopes. 4. Outlet Works. Several options and alternatives were considered for the outlet works. The various alternatives wUl depend on the Intended future use of the reservoir. Outlet conduit sizes from 24 Inches In diameter to 48 Inches In diameter were considered and the capacity of each of these are shown In Figures C-5 through C-8 In Appendix C. The outlet works wUl consist of a screened Intake structure, outlet conduit, outlet control structure, an energy dlsslpator and a Parshall flume. Control gates wlil be required and wlil be Incorporated Into the Intake control structure. If a single outlet conduit Is utilized, a 48-inch conduit wlil be required to meet the State Engineer's requirement to be able to release the water from the top five (5) feet of the reservoir at a rate of one (I) foot per day. Figure C-ll and C-12 In Appendix C show the time required to lower the reservoir by one foot for both the 42-lnch and 48-lnch conduits. If two outlet conduits are utilized, a minimum size of one 42-lnch and one 24-lnch conduit wlil be required to lower the reservoir at a rate of one foot per day. The options that wlil be considered further wlil be an outlet consisting of one 24-lnch and one 42-lnch conduit. This option Is expected to meet the range of future needs of the Company and wlil provide the upper range of costs expected. The use of two conduits may be required to meet releases to other entities that may be supplled out of the reservoir. With two outlets, North poudre can set releases for Irrigation and still deliver water to other users without disrupting the Irrigation demands. The outlet conduits considered wUl be reinforced concrete pipe (RCP) bedded on concrete. A steel pipe encased In concrete was considered and will be more closely scrutinized In the final design depending on the style of outlet required. The costs were estimated for a steel outlet pipe and were determined to be similar to that for the RCP conduit. Some savings may be reallzed In the final analysis using the steel pipe. PAGE II Cblpter V - Wo. 6 l'eulbUlty