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The Rio Grande conveyance channel near Bernardo, N. Mex., was the site for a field study of mechanics of flow and sediment transport. During the period of study, the channel bed consisted of sands with median diameters ranging from 0.15 to 0.35 millimeters, and the bed form varied from dunes to flat. A few data were obtained at two other locations in the channel system. The report summarizes the basic hydraulic and sediment data obtained during the study. Brief descriptions of equipment and procedures of sampling are followed by descriptions of two sets of data. The first set, consisting of a series of measurements taken at individual cross sections, is intended to be descriptive of conditions at successive points along the reach. The second set consists of a series of measurements characterizing the entire length of the Bernardo reach of the channel system. The data described, which include water discharge, crosssectional area, channel width, slope, point velocity, pointintegrated sediment concentration, depth-integrated sediment concentration, and bed material, are summarized in eight tables. Data were obtained for water discharges ranging from 560 to 1,860 cubic feet per second and slopes ranging from 0.00041 to 0.0011. Also observed were cross-sectional area variations from 143 to 425 square feet and suspended-sediment concentration, of materials in all sizes, ranging from 1,240 to 7,700 milligrams per liter. Jl J2 RIO GRANDE CONVEYANCE CHANNEL, NEW MEXICO, 1965-69 106°51 FIGURE 1. Location of channel near Bernardo, N. Mex. Numbers along channel designate every 20th sampling section. Sampling sections are between stations at 100-foot increments on each side of the channel.

This report describes the results of an investigation in progress and presents some tentative findings from a study of hydrology and sedimentation of three small watersheds where soil conservation practices are being applied. The study was begun in April 1954, to determine precipitation, runoff, probable sources and yields of sediment, and channel changes in two small watersheds in Pennsylvania. This report covers the period April 1954, to September 30, 1955 with the exception of the aggradation-degradation range data which covers the period October 1954 to November 1956. The internal or time control method of calibration is being used for the Bixler Run watershed study, and an external control is being used in the Corey Creek study. Precipitation on Bixler Run watershed was 47.33 inches for the 1955 water year. Total runoff was 14.08 inches and the suspended sediment yield was 1,143.3 tons or 76 tons per square mile of drainage area. Precipitation on Corey Creek watershed for the same period totaled 35.81 inches. The total runoff was 8.37 inches and the suspended-sediment yield was 713.0 tons or 58.2 tons per square mile of drainage area. The precipitation on Elk Run, external

_________________________________________________________ Ml Introduction. _____________________________________________________ Purpose of survey.____________________________________________ Acknowledgments _____________________________________________ Location and description of reservoir________________________________ Hydrographic survey.______________________________________________ Horizontal control.___________________________________________ Vertical control._______________________________________________ Office procedure-___-_________-_________^________________-_________ 26 Sedimentation ____________________________________________________ Future sedimentation._________________________________________ 41