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of the dam cut off water supply to approximately 3,000 acres of land. The basin suffered a severe recession and many families moved from the area. On September 9 and 10, 1933, a flood was caused by heavy rain on the divide separating Cherry Creek from Plum Creek, Big Dry, and Little Dry Creeks, which enter the South Platte River between the mouth of the South Platte River canyon and Denver. In an investigation of this flood, the office of the State Engineer made a slope-area determination of the flow in Plum Creek and found it to be 5,500 cfs. A large storm front moved into southeastern Colorado on August 25, 1945, and extended over the Cherry Creek Basin. Unofficial rainfall amounts varied from 2 to 5 inches. Severe flooding occurred along Cherry Creek in the Franktown- Parker area. The gaging station at Melvin recorded a peak discharge of 107,000 cfs. Total damages were estimated at $200,000. High intensity, heavy rains occurred at three locations in the Plum Creek Basin on the afternoon of June 16, 1965. Over 12 inches fell near Castle Rock and over 14 inches fell near Palmer Lake and near Larkspur in approximately 4 hours. East and West Plum Creeks crested at 126,000 cfs and 38,000 cfs, respectively, during the afternoon. The unit run off above the site on East Plum Creek just downstream from Castle Rock was 1,170 cfs per square mile for a drainage area of approximately 108 square miles. Western tributaries of West Plum Creek and all tributaries of Plum Creek downstream of Sedalia were out of the high rainfall areas and contributed little or no runoff during the flood. The combination of steep slopes, sand and gravel streambed, and relatively open and straight reaches of Plum Creek near Louviers was conductive to high velocities and standing waves. The computed mean velocities in seven cross sections surveyed after the flood were near 15 cfs, which implies maximum velocities of approximately 20 to 22 cfs. The amount of scour and fill, the size of the cottonwood trees that were uprooted or bent over, and the matted condition of the debris on trees confirmed the computed velocities. The damage in rural areas of Plum Creek basin was extensive. The heavy runoff deposited all kinds of debris, from sand to huge boulders and trees, on fields and pastures. Road embankments were severely eroded and bridges on County, State and Interstate highways were destroyed. Large-cut banks, particularly along East Plum Creek, were left after land had been washed away. Much of the Town of Castle Rock was inundated, and service to approximately 100 telephones in town was disrupted. Seven homes, a church, the Grand Hall, and the lower part of the main street in Sedalia vanished during the flood. The Denver and Rio Grande Western Railroad between Denver and Palmer Lake, built in 1871 -72, had never been damaged as extensively as it was in 1965. Five bridges, many culverts, and about 4 miles of track were damaged. The track was out of service for approximately 6 weeks after the flood. Repairs to the facilities cost $468,000. The Atchison, Topeka, and Santa Fe Railway also follows the South Platte River and Plum Creek, and repairs, primarily to one bridge, cost 15