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q be considered in evaluating the flood boundary and depths at the subdivision; for the reasons explained earlier. FLOOD INUNDATION The estimate of the water level elevation during the 1121121 year flood is described in this section which will result in the boundary and water depth of the 1121121 year flood. Three Cl'''OSS sect ions, showY. on the previous map, were taken along the half mile length of tHe subdivision. A cross section was taken at each end and or.e about in thE! middle. The three sectior,s adequately represer,t the area becallE;e the topography is sloped uniformly downstream and the width of the ~hannel is consistantly decreasing. The three cross sections are plotted on the attached drawings. As can be seen the flood channel decrease~ in width as it goes downstream; the charmel is about 134121 fee'" wide at the upper section, 11215121 feet wide in the middle, and about 65121 feet at the lower section. The flood chanY'el is very well defined through the entire reach with very steep slc>pes con each bank of the char,nel. The elevation at the upper lot ranges from 7326 feet to 732121 feet depending upon the 10catioY' on the lot. The elevation of three lots is about 7313 feet at the upstream end and about feet at the lower end. The thrse lots are about 11121121 feet long the elevation decreases evenly from the upsream end to dOll'lnstream end. The Mannir,g's eqllation was used t,~ estimatE> the watel" depth at the thre~ flood flows and the three cross sections. The flood flows were 18,121121121 cfs, and 26,121121121 cfs representing the low and high estimates described.ri'n the previous Sl5ction. I~ value of 121.1216 was used for IINII because there are many obstruct iOYIS such as trees, brr~sh, fences, houses, etc. in tl,e flood channel. The channel slope, cross sect iona.l area, and wetted perifl:'leter were est irnated from sUt'vey data taken at the three Cl'OSS sect ions. The est imated water elevations at the three secti'~ns for the two flood flows are listed in the table below. The ground elevation of the center of the island is shown in the last row of the table at each cross sect ion. the 7293 and the Flood Water Elevation Cfeet) Flood Flow Ccfs) --------------------------------------------- Upper Sect i'On' Middle SE~ct i orl LOWE:"r Section 18,121121121 7325.2 7313.9 7298.4 26,12Ie1121 7326 7314.8 7299.7 Island 7325 .7313 729L~ As can be seen there is very little difference be,tweerl the water elevations for the two flood flows. Once the water leaves the