FLOOD10452 (2) - Laserfiche WebLink

Home Browse Search

Three separate floods occurred during May and June 1864. The first originated in the Cherry Creek and Plum Creek basins, occurring during the night of May 19- 20, 1864, and was caused primarily by a cloudburst in the upper part of those basins. On the morning of May 20, the flood inundated the lower portions of Denver at a depth of 1 to 5 feet, leaving great deposits of sand and gravel. Records indicate that 2.08 inches of rain occurred during a 2-hour period on July 14, 1912. The heaviest. precipitation occurred between Franktown and a point about 5 miles north of Denver; the center was located near Parker. The rainfall started around 3pm and continued until around 5pm. Cherry Creek crested around 10pm and had a peak discharge of 25,000 cubic feet per second (cfs) in Denver. The Cherry Creek Flood Commission estimated that runoff occurred from an area of approximately 200 square miles. Flood damages in the reach between Franktown and the site of the existing Cherry Creek Dam and Reservoir totaled $554,000. In June 1921, the rainfall extended east of the mountains for a considerable distance, and the plains tributaries as well as those in the mountains contributed flow into the South Platte River. No gaging stations were being maintained at the mouths of the tributaries. This flood caused the South Platte River to rise approximately 7 feet in Denver. The local press estimated that approximately 500 houses were inundated and many families were forced to seek higher ground. Three large packing plants and practically all of the lower feeding pens at the Denver Union Stockyards were flooded. Ten acres of railroad yards were flooded to a depth of I-foot (U.S. Department of the Interior, 1943). A severe storm centered over the Bayou Gulch Basin, a tributary to Cherry Creek, during the afternoon of July 28, 1922. Heavy rainfall was reported to have occurred in an area bounded by lines 3 miles north of Parker, 4 miles west of Cherry Creek, and 1 mile south of Franktown, and by the Douglas-Elbert County line on the east. Unofficial rainfall amounts varied from 1 inch and 3.5 inches and occurred in approximately 2 hours. An estimated peak flow of 8,700 cfs discharged out of Bayou Gulch. The discharge on Cherry Creek, 3 miles north of Parker, was estimated to be 17,000 cfs. Although no damage was experienced in Denver, this was considered a major flood for the upstream part of the basin. The storm of August 2 and 3, 1933, occurred over a 175 square mile area upstream from Franktown. Unofficial rainfall amounts varied from 3 to 9 inches and occurred over a 9-hour period between 6pm on August 2 and 3am on August 3. The most intense activity of the storm occurred between 9pm and 10pm. Waters in the existing Castlewood Dam and Reservoir reached the spillway crest around 11pm. The inflow was estimated at 35,000 cfs. Water overtopped the crest of the dam and the structure failed around 12am. The sudden release of water caused a flood wave to move down the valley. The peak discharge is estimated to have ranged from 126,000 cfs downstream of the dam to approximately 16,500 cfs near the confluence with the South Platte River. The Cherry Creek Flood Commission estimated the damages to be approximately $1 million; approximately $200,000 of this total occurred upstream from Denver. This flood caused additional economic damage to the Cherry Creek basin. Loss 14