In January, June, and July 1938, and June 1939 parts of Texas experienced floods that exceeded previously recorded stages at many places and that were unusually high over reaches of several hundred miles on the streams of the State.
The floods were caused by heavy rainstorms that covered a total area of about 30,000 square miles in three widely separated parts of the State. These storms occurred in northeast Texas, in the Panhandle-plains region of north Texas, and in the upper Colorado River Basin in northwest-central Texas.
Heavy rains occurred in January 1938 over an area from Texas to Tennessee. In east Texas the maximum precipitation recorded for a 24-hour period was 5.35 inches and for a 7-day period was 10.73 inches. Higher stages occurred on the Sulphur River than any previously known on that river. The resulting peak discharge at Darden, for instance, was 92.900 second-feet from a drainage area of 2.754 square miles, or 33.7 second-feet per square mile. High but not record-breaking stages occurred on Cypress Creek and the upper Sabine River.
A cloudburst rain that lasted from 1 to 4 hours during the night of June 15, 1938, fell in Lake Creek Basin in the Panhandle-plains regions and amounted to 14 inches at one place. The flood was the greatest known in Lake Creek: the peak discharge as determined near Hedley was 64,700 second-feet from a drainage area of 68.5 square miles, or 945 second-feet per square mile.
During July 16-25, 1938, heavy rains fell in the cupper Colorado River Basin and centered in the watershed of the San Saba and South Coneho Rivers, with 30 inches of rain reported from one place and 20 inches or more from about 70 places. More than 15 inches fell in an area of 5,700 square miles. The greatest 1-day rain reported was 13 inches; one observer reported 5.50 inches of rain fell in 1 hour.
The resulting flood in the Colorado River was the greatest on record from the mouth of the San Saba River to Buchanan Dam, and the peak discharge just below the San Saba River was 224,000 second-feet.
The rainfall over the 434 square miles of the South Coneho River Basin above Christoval averaged 19.7 inches. A peak discharge of 100,000 second-feet was determined at the Christoval gage, where the stage was about 1 foot lower than in August 1906.
The 3,100 square miles drained by the San Saba River received a rain of from 12 to 25 inches that averaged 18.8 inches over the basin. Richland Creek, tributary to the San Saba River, received a rain of from 20.5 to 22.5 inches that averaged 21.1 inches over the area. The maximum discharge measured on the San Saba River was 208,000 second-feet at San Saba. The pea discharge of Richland Creek near Richland Springs was 61,000 second-feet from a drainage area of 72.4 square miles, or 843 second-feet per square mile. The floods in the San Saba River exceeded any since 1899 and were the greatest known at many places on streams in the San Saba River Basin.
Measurements of the silt content of the Colorado River during the flood of July 1938 show a maximum 24-hour load at Austin of 2,383,000 tons and a total load for the flood period of 8.030,600 tons.
Studies of the rainfall and the associated direct runoff at river-measurement stations in the Colorado River Basin show that for the storm of July 1938 an average of about 19 inches of rain fell on several areas and the maximum direct runoff was 5.05 inches. The difference between the total rainfall and the direct runoff, or the basin retention, averaged 14.9 inches for those basins receiving more than 18 inches of rain and 10.0 inches for those receiving from 11 to 15 inches. In June 1939 a rain of from 4 to 19 inches fell in from 4 to 10 hours on an area of about 1,000 square miles in the upper Colorado River Basin. The resulting flood in the Colorado River at Colorado, had a peak discharge of 72,800 second-feet and was the greatest known at that station.
This report presents records of precipitation a
Additional Publication Details
USGS Numbered Series
Texas floods of 1938 and 1939
Water Supply Paper
U. S. Govt. print. off.,
vi, 116 p. :incl. illus. (maps, diagrs.) tables. ;23 cm.