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<br />F10odflows from Sand Creek caused high stages on the South Platte River as far as
<br />Fort Lupton, about 29 miles downstream from Denver. Discharges of Sand Creek at
<br />its mouth were estimated to be 15,000 cubic feet per second. Sand Creek discharged
<br />7,720 cubic feet per second at East Colfax Avenue. Flood depths up to 8 feet were
<br />reported. Roads and culverts in the storm area were eroded and damaged. Agri-
<br />cultural lands in the Sand Creek flood plain were damaged by erosion. Water
<br />inundated many homes, some tourist cabins, an oil refinery, and business places
<br />along U.S. Highway 40. Along the South Platte River, 1,000 acres of low-lying crop
<br />and pasture lands were flooded and several county road bridges were damaged. In
<br />Aurora, Westerly Creek overflowed and halted traffic on Colfax Avenue for about
<br />2 hours, inundated 32 homes, and caused the sewage treatment plant to close. Damages
<br />along Sand and Toll Gate Creeks, along the South Platte River, and along Westerly
<br />Creek were estimated to be $133,000, $20,500, and $14,900, respectively.
<br />"Flood of 8 and 9 May 1957. A heavy rainstorm occurred over the Sand Creek
<br />basin and adjacent areas on 8 and 9 May 1957. Over 4.0 inches of rainfall occurred
<br />at the storm center. Major flooding resulted on Sand and Toll Gate Creeks. Run-
<br />off from the Sand Creek basin caused severe flooding along the South Platte River.
<br />The floodwaters in the Sand Creek basin receded in less than 12 hours, but flood
<br />conditions along the South Platte River continued for several days. Maximum
<br />discharges recorded to that date occurred on Sand and Toll Gate Creeks. On Sand
<br />Creek, near Stapleton International Airport, the flow was estimated to be 25,000
<br />cubic feet per second. Upstream from Toll Gate Creek, the Sand Creek discharge
<br />was estimated to be 8,000 cubic feet per second. The Toll Gate Creek discharge
<br />was estimated to be 10,500 cubic feet per second at East 6th Avenue in Aurora.
<br />Discharges on the South Platte River at Henderson and at Fort Lupton were esti-
<br />mated to be 12,000 and 10,000 cubic feet per second, respectively.
<br />
<br />"In its 1 ower reaches, Sand Creek spread over wi de areas. From Buckl ey
<br />Field to the mouth of Sand Creek, the.flood width varied from 500 to 2,500 feet.
<br />Average flood widths along the downstream reaches of Toll Gate Creek were 1,000
<br />feet. Agricultural areas, public utilities, residences, and government property
<br />sustained severe damages. Homes were flooded, the sewer line and oxidation beds at
<br />the Altura sewage plant were destroyed, and three homes near Commerce City were
<br />undercut and toppled into Sand Creek. Most of the bridges across Sand Creek between
<br />Colfax Avenue.and the South Platte River were damaged or destroyed. The embankment
<br />protecting the approaches to the Burlington Ditch Siphon, near the mouth of Sand
<br />Creek, was overtopped, causing floodwaters to follow the ditch and to flood areas
<br />outside the natural flood plain. Three lives were lost along the downstream reach
<br />of Toll Gate Creek. Bottom lands along a 29-mi1e reach of the South Platte River
<br />channel were flooded. Crops and pasture land in the area sustained almost total loss.
<br />Large areas of land were eroded. Heavy damages were sustained by highways and bridges,
<br />railroad embankments, and by irrigation ditches. Floating debris partially clogged
<br />numerous bridges and caused floodwaters to overtop bridge embankment fills. Flood
<br />losses on Sand and Toll Gate Creeks amounted to $338,000. Damages on the South
<br />Platte River were estimated to be $2,000,000.
<br />"Flood of 16 and 17 June 1965. The catastrophic rainstorms of June 1965 also
<br />included major flooding in the Sand Creek basin. Rainfall up to 14 inches fell
<br />on the Plum Creek basin during the afternoon and evening of 16 June 1965. The storm
<br />pattern extended over Sand and Toll Gate Creeks with rainfall averaging 2 to 4 inches
<br />over the Sand Creek basin. Resulting discharges on Sand Creek were estimated to
<br />be 13,400 cubic feet per second at Sable Avenue and 18,900 cubic feet per second
<br />downstream from Toll Gate Creek. Toll Gate Creek flow was estimated to be 17,000
<br />cubic feet per second at East 6th Avenue in Aurora. Heavy runoff from Sand and
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