Suspended matter in the Colorado River in 1925-1928

Determinations of the quantity of solid material carried by the Colorado River are necessary for the proper consideration of plans for the development of the resources of the river. Much of the material carried by the river will be deposited in the proposed reservoirs and eventually will occupy a large part of the capacity of the reservoirs, so that their effectiveness for flood control or river regulation will be greatly decreased. A capacity of 6,000,000 acre-feet is reserved for silt storage in plans for a reservoir in Boulder Canyon that is to have a maximum capacity of about 25,000,000 to 30,000,000 acre-feet. It has been estimated that such a silt-storage capacity will not be entirely used for nearly 100 years.¹ However, the discharge of sediment including the sediment from the Gila was reported to be more than 1,000,000 acre-feet for the four years 1909-1912² and a similar quantity for the four years 1912-1916^.3