Prehearing Statement of the Town of Silverton

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• e. Reasonable Demand Experience by the Town of Silverthorne confirms that there is more than sufficient demand for kayaking and rafting on the Blue River during the May through September period to justify the RICD at present and in the future. f. Limitations on Time of Day, days per Month, and Seasons for RICD Each of the three structures shall be designed to fully capture and control the entire requested flow in the Blue River. Under these requested flows (100 cfs low flow, and 600 cfs high flow), the entire streamflow shall pass through the structure, and pass from sub-critical flow upstream to supercritical flow at the structure. Mr. Lacy provides more detailed design information in his testimony. The schematic design of the structures is presented in Exhibit F (Plan View), Exhibit G(Section View), and Exhibit H(profile) view. The structures tie into the banks of the Blue River and into the channel bottom on the upstream and downstream ends. The design of the structures includes two flow passes, that would fully control the flow at both high and low flow. g. Depth and Flow Rate for RICD Low flow rates are requested for passage of various type of watercraft, • including rafts, canoes, kayaks, and inner tubes from May 1 st to September 30th. The basis for the 100 cfs flow rate is to provide a minimum depth of 2 feet and a minimum width of 10 feet, in order to allow for, and facilitate, recreational boat passage. The control structures have been located and sized to maintain this flow and depth. These flows and depths were recommended by Mr. Gary Lacy, P.E., and are discussed further in his testimony. A standard weir equation was applied to determine the flow required to maintain these depths and flows: Q=3.3*L*h312 (1) where L is the width of the opening (10 feet) and h is the depth (2 feet) of the flow through the structure, thereby resulting in Q= 93.3 cfs. In order to provide for a margin of safety for the 2 feet depth, a flow of 100 cfs is requested. Low flows (100 cfs) are requested during warm weather months (May - September) and for daylights hours (7:00 am to 8:00 pm). These dates and times are consistent with the Town of Silverthorne's plans for recreational boat passage in the Blue River. High flow rates are requested to create white water experience for kayakers with 2 feet of depth through the control structures. A flow rate of 600 cfs was selected based on a recommendation by Mr. Lacy ( see the following • calculations) Similar to the low-flow calculation, a weir equation was used to