| OCR Text |
Show Record was a peak flood of 7980 second feet. All of these gaugings were taken at the town of Green River. We experienced the flood 192 of October 14 and 15. We were at that time below the mouth of the San Rafael. There is no gauging station on the San Rafael and there was some contributing flow from that stream. The silt in a river is measured by taking samples of the water and allowing it 193 to settle; or it can be determined by weighing. The estimates as to silt content appearing in my report are based on scientific investigation. The amount of silt shown on page 78 of my report indicates that there may be between 10,000,000 and 30,000,000 cubic yards of sediment carried annually into the canyon at Green River. 194 The bar formations clearly indicate that the San Rafael and other tributaries bring in debris, and the falling of the banks of sand bars also contributes to the silt in suspension. The wind con- 195 tributes to some extent to the sediment. In my opinion the large motor- boat, with a 21/ 2 foot draft, could not have been brought up to the town of Green River, Utah. Between the mouth of the San Rafael and the mouth of the Green there is practically no stretch that you could call " straightway" river; it is winding, tortuous throughout. Between Miles 7 and 8 and between Miles 35 and 37 it 196 is practically straight; also between Miles 27 and 29. At Horseshoe Bend, shown on Plate 33, it is approximately seven miles 197 around by the river and a quarter of a mile across the neck. On these plates I have shown in red ink by number and initials all pho-tographs referred to in Exhibit 77; the red arrows indicate the lo-cation number and volume number of all photographs in the files of the Geological Survey; the mileage above the mouth of the river appears in a circle. Plate 3 of Exhibit 76 indicates the approximate channel conditions of the river as shown by General Land Office 198 plat dated June 6, 1883. Said plat shows a town that was then known as East Blake. In 1928 I found the main channel of the river flowing probably half a mile away from East Blake as located on 199 said 1883 plat. There is a statement signed by officials of the |
