Sediment discharge during floods in eastern Nebraska

Runoff resulting from rapid melting of a deep snow cover over much of eastern Nebraska resulted in exceptionally high stream stages and in severe flooding on many streams in eastern Nebraska during the latter part of March and the early part of April in 1960. Suspended-sediment concentrations and discharges for most of the streams were somewhat lower than would be expected during similar water discharges that might result from torrential rains rather than snowmelt. During the period March 28-April 8, 1960, when the total water discharge of Platte River at Louisville and of Elkhorn River at Waterloo was about one-fourth of the total for the year, the sediment discharge was an estimated 46 to 50 percent of the estimated total for the year at each station. Both the percentage of sand and the concentration of sand in the suspended sediment were much higher for the Platte and Elkhorn Rivers than for streams in the Big Blue River and Nemaha River basins. For Platte River at Louisville and for Elkhorn River at Waterloo, measured sediment discharges ranged from about 87 to 94 percent of the computed total sediment discharge.