Quality of water of the Colorado River in 1926-1928

This report gives the results obtained in the continuation of a study of the Colorado River begun in 1925.¹ Most of the analyses here given represent composites of daily samples collected by the observers at the gaging stations on the Colorado River at Grand Canyon, Topock, and Yuma, Ariz. The other samples analyzed were taken at Lees Ferry and on tributaries of the Colorado. These stations are operated under the direction of W. E. Dickinson, district engineer of the Geological Survey at Tucson, Ariz., who personally collected some of the samples at other points and arranged for the collection of others. The average discharges in Table 2 were calculated from data furnished by W. E. Dickinson. Complete discharge data for this period will be published in the regular series of water-supply papers.