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1 <br /> 1 <br /> 1 <br /> 44 _II <br /> ____,,, ._ ,.,.,, V <br /> 1* i 1 <br /> C4 I <br /> II <br /> 2o_ba° 1 1 1 <br /> i <br /> Cable <br /> / Connection <br /> / i <br /> Scour Hole <br /> \ <br /> II 1 <br /> i <br /> -- l <br /> DLR <br /> Figure 7. Root wad/log vane/J-Hook combo <br /> streambank stabilization and fish habitat structure <br /> increases the"center-channel" shear stress. The center of the channel associated with the hook is <br /> efficient at transporting sediment, debris and improving channel capacity and sediment <br /> competence. The"shooting flow" associated with the hook portion of the structure provides for <br /> recreational boating in moderate to larger sized rivers. Width/depth ratios are maintained by <br /> decreasing bank erosion rate and increasing bankfull channel depth, even following major floods. <br /> Design Specifications <br /> Cross-Vanes, W-Weirs and J-Hook Vanes <br /> Vane angle. The vane arm portion of all three structures is generally 20-30 degrees measured <br /> upstream from the tangent line where the vane intercepts the bank. The 20-degree angle <br /> provides the longest vane length and protects the greatest length of streambank. Variation from <br /> 20 to 30 degrees is often utilized in offset Cross-Vanes and/or W-Weirs whose asymmetry <br /> disproportionately shift more water to one side of the structure often used for irrigation <br /> 11 <br />