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<br />The City of Littleton borders the City and County of Denver, the
<br />Ci ty of Sheridan, the Ci ty of Englewood, the Ci ty of Greenwood
<br />Village, Arapahoe County, Douglas County, the Town of Columbine
<br />Valley, Jefferson County, and the Town of Bow Mar.
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<br />The city has an annual mean temperature of 50.20 F, and an average
<br />growing season of 139 days. The average annual preclpltation
<br />consists of 14 inches of rainfall and 45.6 inches of snowfall.
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<br />The South Platte River is a continuous flowing stream, whereas its
<br />tributaries are intermittent flowing streams. The South Platte
<br />River has two major types of flooding: snowmelt and summer
<br />weatherfronts or thunders terms. The t ri butary bas ins are narrow,
<br />hydraulically steep, and composed of highly erodable, clay-loam
<br />soils. In the undeveloped portions of the city, the ground cover
<br />is predominantly a short grass ~alled "buffalo grass"; willow and
<br />cottonwood trees grow throughout the city.
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<br />Development has occurred up to the steep, incised channels on the
<br />tributaries. The development on the South Platte River floodplain
<br />in the past was mostly agricul tural, but today is commerciat',
<br />industrial, and residential. In various reaches of the ci ty' s
<br />floodplain, pressure by developers to expand continues to exist.
<br />The city government, with the support of many citizens, is actively
<br />working to retain the open space of the floodplain areas. A
<br />notable example of this is the Littleton Flood Plain Park,
<br />approximately 625 acres through which the South Platte River
<br />meanders.
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<br />2.3 Principal Flood Problems
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<br />The South Platte River, a perennial stream, flows through the west-
<br />central portion of Littleton in shifting channels with broad,
<br />shallow beds and low, flat overbanks. The other streams in the
<br />community, tributaries to the South Platte, are ephemeral, and have
<br />steep, narrow channels.
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<br />All of the tributary stream channels studied have had various
<br />structural improvements, but the intense and infrequent
<br />thunderstorms characteristic of the area can generate floods in
<br />excess of existing structural capacities.
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<br />In 1844 and 1864, reports read that "bottomlands near Denver were
<br />covered with water bluff to bluff." By 1876, encroachment into the
<br />floodplain had developed to such an extent that on May 23, 1876,
<br />the Rockv Mountain News reported that "(The South Platte River) was
<br />higher to be sure--several feet higher perhaps in 1864--but it was
<br />not able to work such destruction at that time as now. There was
<br />not so much town here in 1864, as now, nor as many bridges."
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<br />The large magnitude floods on the river in 1894,1921,1933, and
<br />1965 had estimated discharges in Denver of 14,000 cubic feet per
<br />second (cfs), 14,000 cfs, 22,000 cfs, and 40,300 cfs., respectively.
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