Laserfiche WebLink
4-36 <br />• depth. A friction factor, or "Idanning' s n", of 0.050 <br /> was used. The slope of the channel is relatively constant <br />throughout the reach. The slopes used in the Manning equation, <br />which were estimated from the mapping, are shown in Appendix <br />The resulting hydraulic characteristics are expressed <br />as rating curves (flow depth versus flow rate) and are <br />shown in tabular form in Appendix <br />The flood discharges for specific recurrence intervals were <br />applied to the rating curves to determine flow depths for <br />floods of those recurrence intervals at each of the cross- <br />sections. These flow depths were plotted on the cross- <br />sections to determine the width of the floodplains. The <br />• maximum water surfaces expected from the flood are also <br /> shown on these figures. The cross-sections are shown on <br />Figures 4.5-7 and 4.5-8. <br />The 100-year floodplain for Munger Canyon near the waste rock <br />disposal area is between about 16 feet and 26 feet wide (see <br />Table 4.5-6). In all cases, the 100-year floodplain is <br />contained within the existing, deeply incised channel. The <br />relationship between the 100-year floodplain and the waste <br />rock disposal area is shown in plan on Figure 4.5-6. <br />Although Fi~y~re 4.5-6 shows the 100-year floodplain only <br />along the waste rock disposal area, the floodplain should have <br />similar dimensions in other parts of the permit area. Through- <br />. out the lower reaches of the permit area the channel of Munger <br />