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E.E. Schroeder

Publications and source records attributed to E.E. Schroeder.

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Floods in central Texas, August 1-4, 1978

Catastrophic floods caused by record rainfall occurred in central Texas during August 1-4, 1978. Torrential rain initiated by the remnants of tropical storm Amelia fell over south-central Texas during August 1-3, and very intense rain due to the interaction between the cold front and maritime air mass fell over north-central Texas on August 3-4. Rainfall of more than 48 inches near Medina in south-central Texas established a new United States record of extreme point rainfall for a 72-hour period. Major flooding occurred on the Medina and Guadalupe Rivers. Severe to minor flooding occurred on the Brazos, Llano, Pedernales, and Nueces Rivers. Floods with recurrence intervals in excess of 100 years and recordsetting peak discharges were observed at several streamflow stations. Thirty three lives were lost and total damages reportedly exceeded $110 million.

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Floods in central Texas, August 1978

Catastrophic floods, which resulted in millions of dollars in property damages and the loss of 33 lives, occurred in Central Texas during August 1-4, 1978, as a result of intense rainfall produced by the remnants of tropical storm Amelia. Rainfall in excess of 30 inches was unofficially reported at several locations, while the highest 24-hour amount recorded by the National·Weather Service was 29.05 inches at Albany in Shackelford County. Major flooding occurred on the Medina River and triputaries above Medina Lake and on the Guadalupe River and tributaries above Canyon Lake. Minor to severe flooding occurred on the tributaries of the Nueces River, on the Clear Fork Brazos River and tributaries, and on the Llano and Pedernales Rivers, which are tributaries of the Colorado River. Peak discharges at several streamflow stations exceeded the historic peaks, and the flood magnitude and frequency data for the Guadalupe River above Canyon Lake, the Medina River near Pipe Creek, and Clear Fork Brazos River indicate that the August 1978 flood had a recurrence interval in excess of 100 years. The highest unit discharge observed during this flood was 3,010 cubic feet per second from a 14.1-square-mil.e drainage area of Spring Creek, which is tributary to the Pedernales River.

Open-File Report↗

Technique for estimating the magnitude and frequency of floods in Texas

Drainage area, slope, and mean annual precipitation were the only factors that were statistically significant at the 95-percent confidence level when the characteristics of the drainage basins were used as independent variables in a multiple-regression flood-frequency analysis of natural, unregulated streams in Texas. The State was divided into six regions on the basis of the distribution of the residuals from a single statewide regression of the 10-year flood. Equations were developed for predicting the magnitude of floods with recurrence intervals of 2, 5, 10, 25, 50, and 100 years in each of the six regions. These equations are applicable to unregulated rural streams with drainage basins ranging in area from 0.3 square mile to about 5,000 square miles in some regions. Regression equations were not developed for several areas, particularly in south Texas, because of the lack of definition of the flood-frequency characteristics.

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