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n01596 Alternatives, Including Proposed Action 2-26 An additional site, including 300 feet of hard points at site 32A, has since been added. Most sites are located at bends where there is ample room for the river to widen on its opposite side. The river would therefore tend to widen in the direction opposite to the stabilization. Figures 2-10 and 2-11 show the general locations of the bank stabilization measures. Table 2-2 summarizes stabilization proposals by protection type; Table 2-3 presents the same information, segregated by selection criteria. Bank energy indexes were calculated for each potentially feasible altemative (E-l, E-2, and E-3). Although values changed, the net result was the same recommended overall protection plan for each of these options. One site dropped below the BEl threshold criterion for 750 cfs. However, it was retained in the program because field judgement indicated that is would likely erode at flows well below 750 cfs, and an agricultural field would be at risk. Not all cases of bank erosion need to be arrested. The reason is that the natural erosion and accretionS process is generally considered to be environmentally beneficial, providing the dynamic conditions necessary for wetlands rejuvenation and growth. In addition, confining the channel on both sides would increase the risk of channel degradation. Table 2-2. Summary of Proposed Stabilization Measures, by Stabilization Type Total Length Rock Volume Type No. of sites feet cubic yards New riprap 13 3,785 8,660 Supplement riprap 12 3,960 5,426 Both new and supplement riprap 3 1,230 2,471 New hard points 17 7,120 3,875 Supplement hard points 5 2,230 940 Total 50 18,325 21,372 Table 2-3. Summary of Proposed Stabilization Measures, by Selection Criteria Criterion Infrastructure Agricultural Special conditions Total No. of sites 24 15 11 50 Total Length feet 7,245 6,320 4,760 18,325 Rock Volume cubic yards 9,623 5,642 6,107 21,372 With the landowners' permission, construction access to bank stabilization sites would be provided by farm and field lanes wherever possible. The Sponsors would construct temporary lanes from fields to the bank revetment site where necessary. In places where Accretion means the slow addition of 'and by deposition of water-borne sediment. 'r;- ^' _.~'., = AS Lateral Hydropower Project July 2000