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FENCE JETTIES (WOOD AND WIRE) ==t~ i;, ( 1.- ~~~~-- --~~~T----- 'I r, 1C::".", - "" ", ,,,.~~~g; I ~ ",lIlld ," 11111111 - ",,,'II:IIIWLIIIlIII<""i;IIIII" .", "'~"".. ""1111,, ..tlll L I..... 11111111' "L~1111111..1111 ,\\; "..,"", ,Wood or Wire Fences Normal Water Surrace TYPICAL SECTION " " " " " .c " " " ,: Fence jetties are used to solve a variety of bank protection problems. They can be constructed parallel to the bank as well as transverse to the streamflow. MaterIals for construction can vary. Types often used are treated or untreated wood, used rails, pipe, and steel or concrete beams. The fencing material Is usually wood or wire. If wire fencing Is used, the required tensile strength depends on the design loading by the water and debr r s. Fencing Is not one of the most effective means of bank protection, but is commonly used because no special techniques for construction are required and materials are readily available. Another way to use fences I s to construct two fences para lie I to the bank 3 to 10 feet apart. Brush, hay, or rock is stacked between the fences, providing an extra measure of protection against the erosive action of the water currents. If the fences are constructed parallel to the bank and the bank is steep enough, a second fence Is not required for holding the brush backfill. Fences constructed parallel to the bank generally serve as an erosion stopgap measure to al low sufficient time for the establishment of vegetation or to prevent sloughing of the bank. Fences constructed across part of the stream section promote sediment deposition. A transverse fence can be positioned to deflect debris downstream or to trap It. By constructing the fence so that it is oriented downstream at an obi Jque angle to the current flow, debris wi II be 27