Suspended matter in Colorado River and its relation to the development of the river

Determinations of the quantity of solid material carried by Colorado River are necessary for the proper consideration of plans for the development of the resources of the river. A large part of the material carried by the river will be deposited in the proposed reservoirs and eventually will occupy a considerable portion of their capacity so that their effectiveness for flood control or river regulation will be greatly decreased. The choice of sampling paints and methods of sampling as well as methods for the determination of the quantities in the samples are important factors in studies of suspended matter carried by Colorado River. The quantity of suspended matter is quite different at different points at a given station so that a number of samples are necessary to get a representative value for the quantity carried by the river. The annual load of suspended matter carried by the river as calculated from the samples collected during the period studied was greater at Grand Canyon than at either of the lower station on the river. Since the annual load of suspended matter computed. from samples collected at Grand Canyon was considerably greater than the average load computed from samples collected at Yuma it seems probable that samples collected at Yuma can not safely be used for computing the quantity of material carried by the river. The volume which the material will occupy when deposited in a reservoir is not known but it is probable that on an average less than 86 pounds of suspended matter will be deposited in a cubic foot of reservoir space. The choice of sampling paints and methods of sampling as well as methods for the determination of the quantities in the samples are important factors in studies of suspended matter carried by Colorado River. The quantity of suspended matter is quite different at different points at a given station so that a number of samples are necessary to get a representative value for the quantity carried by the river. The annual load of suspended matter carried by the river as calculated from the samples collected during the period studied was greater at Grand Canyon than at either of the lower station on the river. Since the annual load of suspended matter computed. from samples collected at Grand Canyon was considerably greater than the average load computed from samples collected at Yuma it seems probable that samples collected at Yuma can not safely be used for computing the quantity of material carried by the river. The volume which the material will occupy when deposited in a reservoir is not known but it is probable that on an average less than 86 pounds of suspended matter will be deposited in a cubic foot of reservoir space.