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Water Supply Reserve Account - Grant Application Form <br />Form Revised May 2007 <br />downstream of the diversion dam. The realigninent should have the following effects: <br />a. Floating debris like logs will be more likely to be carried down the main channel over <br />the Core, not through the Diversion Gates, <br />b. Gravel sediments would be scoured from in front of the Diversion Gates and carried <br />down the main channel; and <br />c. Maintenance related to clearing log jarns and removing sediment should be reduced. <br />Some maintenance such as periodic replacements of riprap on the bail, could be <br />needed. <br />Method / Procedure to accomplish Phase I - Temporary Channel Stabilization: <br />Remove debris and move gravel deposition from the south bank, of the main stem above the diversion to <br />the north bank in order to prevent threatened breach. <br />Method / Procedure to accomplish Phase II -- J-Hook Vane rock structures: <br />The tasks for the placement of J-hooks will follow standard accepted procedures and will conform to <br />NRCS specifications. In addition, MLI supervision and consultation will be provided at one quarter time <br />over six months, ensuring that these specifications are met. The J-Hook Vane is an upstream directed, <br />gently sloping structure composed of natural materials, in this case rock. Each structure is located <br />on the outside of stream bends where strong dowmNvelling and upkvelling currents, high boundary <br />stress, and high velocity gradients generate high stress in the near-basil, region. The stricture is <br />designed to reduce bank erosion by reducing near-bank slope, velocity, velocity gradient, stream <br />power and shear stress. Redirection of the secondary cells from the near-bank region does not <br />cause erosion due to back-eddy re-circulation. The vane portion of the structure occupies 1/3 of <br />the bankfull width of the channel, while the ``hook" occupies the center 1/3. Maximum velocity, <br />shear stress, stream power and velocity gradients are decreased in the nearbank region and <br />increased in the center of the channel. Sediment transport competence and capacity can be <br />maintained as a result of the increased shear stress and stream power in the center 1/3 of the <br />channel. Backwater is created only in the near-bard, region, and the small departure angle gently <br />redirects the velocity vectors from the near-bank region, reducing active bank erosion. <br />Method / Procedure - Phase III -- Core & Diversion Gate Structures: <br />The final task involves constructing a new Core directly adjacent to the Diversion Gates. This will allow <br />controlled sluicing of gravel down the main channel during various flow- conditions, reducing gravel <br />accumulations. <br />Expectations: <br />o Phase I - Reshape Riverbed - The intent will be to begin the process of shaping this reach <br />of the Cone los River with the expectation, at the end of the Project, of return* <br />the <br />Ing <br />chamiel, to the best practicable extent, to the condition that existed before excessive <br />movement occurred, about 15 years ago. <br />22