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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Alternative No.4 was selected, since it achieves the first step in removing the current storage <br />restriction, comes in at a reasonable cost, and is most acceptable to surrounding landowners. <br /> <br />The Selected Alternative <br /> <br />The selected alternative, Alternative No.4, involves construction of a 72 inch pipe spillway with <br />an overflow inlet in the reservoir just upstream of the dam, an energy dissipation structure at the <br />terminal end of the pipe, and a short channel from the end of the dissipation structure to the <br />Prewitt outlet canal. <br /> <br />W.W. Wheeler and Associates, Inc. (Wheeler) designed the emergency pipe spillway and the <br />design was approved by the SEO in September of 2005. The approval letter from the SEO can <br />be found in Appendix F. The design is attached to this feasibility study. Wheeler has also <br />prepared a detailed cost estimate, which is presented in Table 1. <br /> <br />Table 1. Prewitt Reservoir - Emergency Pipe Spillway. Cost Estimate <br /> <br />Item Quantity Unit Unit Price $ Amount $ <br />Furnish and Place 72 inch Concrete Pipe (1) 250 Ft 400.00 $100,000 <br />General Excavation (2) 12,000 C.Y. 2.00 $24,000 <br />Structural Concrete (3) 300 C.Y. 350.00 $105,000 <br />Backfill Concrete (4) 100 C.Y. 250.00 $25,000 <br />Vent Pipe 1 EA 1000 $1 ,000 <br />Furnish and Place Pipe Bedding 170 L.F. 35.00 $5,950 <br />Furnish and Place Riprap Bedding 150 C.Y. 25.00 $3,750 <br />Furnish and Place Riprap 275 C.Y. 50.00 $13,750 <br />Furnish and Place Log Boom 1 L.S. 13,000.00 $13,000 <br />Engineering Over-site/As Builts to State 1 Job 15,000 $15,000 <br />Contingency (10%) 1 Job 30,645 $30,645 <br />Total $337,095 <br /> <br />Implementation Schedule <br /> <br />Construction is expected to begin August or September 2006 and to be completed within 60 <br />days. <br /> <br />Permitting <br /> <br />All construction will be done on land owned by the Prewitt Operating Committee and flow from <br />the spillway will be confined to the Prewitt Outlet Canal, therefore no easements or rights of way <br />will be needed. As stated earlier, the SEO has approved all plans and is requesting the Prewitt <br />begin construction. <br /> <br />Logan Irrigation District <br />Emergency Spillway Feasibility Study <br />March 30,2006 <br /> <br />Page 9 of 12 <br />