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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 />Table 2. Wave Analysis and Riprap Sizing Results <br /> <br />. <br /> Wave Design Riprap Riprap <br />Section- Effective Design Wave <br />Fetch Fetch Wind Run-up, Height, Thickness, Diameter, <br /> Rs t 050 <br /> Hs <br /> (mi) (mph) (ft) (ft) (in) (in) <br />lA 1.45 65 3.60 3.50 20 11 <br />lB 1.73 65 3.60 3.70 21 11 <br />2A 1.75 65 3.90 3.70 21 11 <br />3A 1.83 66 4.20 3.95 22 12 <br />4A 1.77 65 3.90 3.70 21 11 <br /> <br />Based on this analysis, 12 inch Dso riprap placed at a thickness of 24 inches meets the USBR standards <br />and was selected for design. <br /> <br />The riprap will be placed atop a 12 inch thick layer of Type II bedding material. Due to the sandy nature <br />of the soils, bedding material is recommended to reduce maintenance costs. Wave action on unbedded <br />riprap that is placed on a non-cohesive sand will result in washing of fines that will cause the riprap to <br />continually settle and unravel. A Type II bedding will give added protection and meets the current <br />standard of practice. <br /> <br />Selected Alternative - Embankment DesiRn <br /> <br />Geotechnical testing of the proposed embankment materials shows that the materials on-site are <br />predominantly silty sands. The percent passing a #200 sieve ranged from 8-38% with 4 out of 6 tests <br />reporting at least 20% passing a #200 sieve. As expected, this material is similar in composition to the <br />original dam. The dam is over 100 years old and the proposed slopes for repair are actually shallower <br />than currently exists. Therefore, No slope stability analysis has been performed at this time. The <br />proposed repairs include compacted backfill at slopes of 3H:1V. The materials tests and past history <br />indicate that the dam will be stable at this slope. Material classification results are included in <br />Appendix C. A copy of the proposed construction plans for the rehabilitation is also included in <br />Appendix C. <br /> <br />ImDacts <br /> <br />The project will have no significant social impacts. <br /> <br />Although shareholders in Bijou will be impacted with increased assessments for construction and loan <br />repayment, the project will have a long-term positive economic impact by allowing Bijou Irrigation <br /> <br />Empire Reservoir East Embankment Dam, Water Division 1 <br />DAMID 010728 <br /> <br />Page 5 <br />