|
<br />D26
<br />
<br />FLOODS OF 1965 IN THE UNITED STATES
<br />
<br />from Pueblo to Lamar, Colo" occurred in 1921. The flood of 1864 was
<br />almost as great as the 1921 flood (103,000 cfs) in Pueblo, A major flood in
<br />1894 was higher than the 1921 flood in the valley upstream from Pueblo but
<br />was considerably lower in Pueblo and downstream, The 1908 flood on the
<br />Arkansas River exceeded the 1921 flood at Holly, Colo" and downstream
<br />into Kansas. The floods of May 1955 in the Arkansas River basin in
<br />southeastern Colorado and northeastern New Mexico were generally the
<br />greatest floods since 1921 on the Arkansas River above the mouth of the
<br />Purgatoire River (Vaudrey, 1960).
<br />The peak discharges of the 1965 flood on the Arkansas River from
<br />Pueblo to Lamar, Colo" were considerably lower than those in 1921 and
<br />also lower than the 1955 peak discharges from La Junta, Colo., to John
<br />Martin Reservoir. They exceeded the 1955 peak discharges in a reach
<br />downstream from Fountain Creek, especially downstream from Chico
<br />Creek. The 1965 peak discharges on the Arkansas River at Holly, Colo.,
<br />and downstream into Kansas were the greatest known. The peak discharge
<br />was not determined at Holly, Colo., but probably exceeded the peak flow of
<br />182,000 cfs from Two Butte Creek, which enters the river just upstream, On
<br />October 20, 1908, the peak flow at Holly was 110,000 cfs. At the Syracuse,
<br />Kans., station the peak discharge in 1965 was 174,000 cfs, compared with
<br />87,000 cfs in 1908.
<br />
<br />The 1965 peak discharge of 47,000 cfs on Fountain Creek at Pueblo,
<br />Colo., was the greatest of record. Peak discharges on June 4, 1921, and May
<br />30, 1935, were 34,000 and 35,000 cfs, respectively. On the Purgatoire River
<br />the peak flows in 1965 generally were less than in 1955. One exception was
<br />at the station near Higbee, where the peak flow was estimated as 105,000 cfs
<br />in 1965, compared with 80,000 cfs in 1955. Peak flows much greater than in
<br />1955 occurred on some of Purgatoire River tributaries.
<br />Extremely high peak flows occurred in 1965 on the south-bank tributaries
<br />of the Arkansas River from John Martin Reservoir to the State line, but
<br />they cannot be compared with historical flows because records are not
<br />available, On Two Butte Creek at Holly the 1965 peak flow was more than
<br />five times the estimated peak flow of 1908.
<br />
<br />The total runoff in the Arkansas River basin in Colorado from the June
<br />1965 storms exceeded that of any previous flood for which there are records.
<br />John Martin Reservoir stored 320,000 acre-feet during June 14-26, and an
<br />additional 485,000 acre-feet of inflow downstream from the dam flowed
<br />past the station near Coolidge, Kans., during June 17-27. Thus, the total
<br />June 1965 storm runoff at the State line, adjusted for storage in the reser-
<br />voir, would be 805,000 acre-feet. Records are not available at the Coolidge
<br />station, but at Holly, only 6 miles upstream, the total storm runoff in 1908
<br />and 1921 was only 285,000 and 410,000 acre-feet, respectively. The large
<br />difference between 1965 and 1921 was because of the high runoff
<br />downstream from Lamar. At Lamar the total storm runoff in 1921 was
<br />
|