Silt Transportation by Sacramento and Colorado Rivers and by the Imperial Canal

Data relating to the transportation of silt or fine sand and other detrital material by the Sacramento and Colorado Rivers and by the Imperial Canal, with inclusion of the results of personal observations, are presented in this paper. Repeated surveys to determine the frequent changes in the elevation of the bed of the Imperial Canal in its upper reaches, and the removal of large quantities of silt from the head reaches, have furnished an exceptional opportunity for estimating the volume of silt transported by the canal, including its bed load. Over a period of 2½ years the available data indicate deposit followed by erosion to have averaged in excess of 500 000 cu. yd. per month, with a canal flow of about 2 000 000 acre-ft. per year.