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Hvdrolow Results <br />• (Using SEDCAD+ computer model: Refer to Table 18, Magpie <br />Creek Diversion - 10-Year, 24-Hour Hydrograph Analysis, <br />at the end of this section, for computer printouts.) <br />Peak Discharge <br />10-year, 24-hour event: 29.63 cfs <br />100-year, 24-hour event: 142.7 cfs <br />Total Design Discharge for Lower Reach of Diversion: <br />10-year, 24-hour event: 172.24 cfs <br />100-year, 24-hour event: 528.6 cfs <br />Diversion Design <br />The Magpie Creek Diversion was designed utilizing Manning's <br />Equation for Open Channel Flow, as discussed in the Methodology <br />and Assumptions section of this exhibit. Design results are <br />summarized in on Map 25A, Magpie Creek Permanent Diversion. <br />EFCI will place two foot high drop structures in the upper <br />portions (sections D-R)of the permanent division to reduce the <br />channel grade to less than 0.5 percent. Splash pans will be <br />constructed at the base of the drop structures and will extend <br />approximately four feet beyond the toe. The drop structures and <br />and pan will be constructed with large rocks (Dso=18"), concrete or <br />Gabion structures. A typical drop structure is shown on Figure 8, <br />Typical Drop Structure. Approximate locations of the drop <br />structures are shown on Map 25A, Magpie Creek Permanent Diversion. <br />The upper portion of Magpie will be lined with vegetation. If <br />required, mulch and or erosion control matting will be utilized <br />to help reestablish vegetation in the channel. The lower portion <br />(section R-W) of the permanent diversion will be lined with <br />riprap. Channel dimensions and riprap requirements are shown on <br />Map 25A, Magpie Creek Permanent Diversion. Riprap sizing was <br />determined using the PADER method. To be conservative, the <br />required riprap size was increased by six inches. Channel design <br />computer printouts are included in Table 19. <br />• <br />TR-32 144 Revised 10/O1 <br />