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<br />Flood of AUGust 1933, The storm of 2 and 3 August 1933 occurred over a 175 square
<br />mile area upstream from Franktown, Unofficial rainfall amounts varied from 3 to 9 inches
<br />and occurred over a 9-hour period between 6 p,m, on 2 August and 3 a,m. on 3 August.
<br />The most intense activny of the storm occurred between 9 p,m, and 10 p,m, Waters, in the
<br />then existing Castlewood Dam and Reservoir, reached the spillway crest at about 11 p,m,
<br />The inflow was estimated at 35,000 cubic teel per second, Water overtopped the crest of
<br />the dam and the structure failed at about midnight, The sudden release of water caused
<br />a flood wave to move down the valley, The peak discharge is estimated to have ranged
<br />from 126,000 cubic feet per second downstream from the dam to about 16,500 cubic feet
<br />per second near the South Platte River, The Cherry Creek Flood Commission estimated
<br />the damages to be about $1,000,000: approximately $200,000 of this total occurred
<br />upstream from Denver. This flood caused addnional economic effects in the Cherry Creek
<br />basin, Loss of the dam cut off water supplies to about 3,000 acres of land, The basin
<br />suffered a severe recession and many families moved from the area,
<br />
<br />Flood of AUGUst 1945, A large storm mass moved into southeastern Colorado on 5
<br />August 1945 and extended over the Cherry Creek basin, Unofficial rainfall amounts varied
<br />from 2 to 5 inches, Severe flOOding oCGurred along Cherry Creek in the Franktown -
<br />Parker area, The gaging station at Melvin recorded a peak discharge of 10,lOll cubic feet
<br />per second, Total damages were estimated to be $200,000,
<br />
<br />Flood of June 1965, On 16 June 1965, a major storm centered over the Plum Creek
<br />and Cherry Creek basins, Rainfall amounts, reported by unofficial sources, ranged up to
<br />10 inches, Most of the rainfall Occurred wnhin a 3-hour period, Peak discharges along
<br />Cherry Creek were 1,000 cubic feet per second upstream from Franktown, 3!l,900 cubic
<br />feet per second near Melvin, and 58,000 Gubic feet per second at Cherry Creek dam, An
<br />estimated peak flow of 14,100 cubic feet per second discharged from Piney Cmek, a right-
<br />bank tributary of Cherry Creek. During the evening and night of 16 June, the Cherry Creek
<br />reservoir impounded a flood which had a volume of 16,000 acre-feet. Of the 18 small
<br />dams constructed by the Soil ConselValion Service in the upper Cherry Creek basin
<br />between Franktown and Parker, 3 were tilled, Two of these were subsequently overtopped
<br />and sustained erosion damage, The remaining 15 structures were outside of the area of
<br />high intensny rainfall and received only moderate runoff, The heavy runoff caused major
<br />flooding along the main stem of Cherry Creek from the vicinity of Franktown to the Cherry
<br />Creek reservoir, About 2,720 acres were flooded, Most of the bridges across Cherry
<br />Creek were enher damaged or destroyed, one life was lost during the flood on Cherry
<br />Creek. Flood damages totaled $1,306,000,
<br />
<br />4.1.6 SAND CREEK BASIN
<br />
<br />Flood Historv. Available data indicate that major flood events in the Sand Creek basin
<br />are caused by runoff from intense thunderstorm-type rainfall, Nine major floods have
<br />occurred in the Sand and Toll Gate Creek basins since 1896, No flood disGharges are
<br />available for floods in 1896,1912,1917,1921,1933, and 1938, The other events are listed
<br />below,
<br />
<br />Colorado Flood
<br />Hydrology Manual
<br />
<br />4,B
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<br />fR'FT
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