FLOOD00850

• Designation Number: 31
• County: Arapahoe
• Community: Unincorporated Arapahoe County
• Title: Major Drainageway Planning - Little Dry Creek, Report, Volume I
• Date: 2/1/1974
• Designation Date: 6/1/1974
• Floodplain - Doc Type: Floodplain Report/Masterplan

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wide, flat, nearly treeless, grassy reservoir area is well suited to re-

creational use. The elevation of the spillway crest is high enough to

back water up to a line of extension of East Dry Creek Road, at which

point Spring Creek joins Willow Creek. Housing development above the high

water elevation of the reservoir is being planned by S.M.S, Joint Venture.

Between a line of extension of East Dry Creek Road and County Line Road,

the channel of Willow Creek winds through prairie lands untouched by urban-

ization. No bridges, culverts, visible pipe crossings, or other flow con-

strictions exist. An as-yet-unused sewer line was constructed in about 1960

along much of this reach of Willow Creek and manhole tops are visible.

Though mostly clear and covered with native grasses, the channel has short

reaches of clustered cottonwood trees and some longer reaches of thick

willow growths. Channel banks in places are steep and subject to erosion.

Spring Creek in Arapahoe County. Spring Creek flows into Willow Creek

near the head of Englewood Dam Reservoir. Its grassy shallow channel is

similar to the Willow Creek channel for a distance of about one mile up

to the Arapahoe County line, the limit of this study. At the county line

Spring Creek passes under County Line Road in a 42-inch corrugated steel

culvert. The culvert is too small to carry flows larger than about 10-

year frequency flood flows without causing extensive ponding and possible

overflowing of County Line Road.

Willow Creek in Douglas County. Except for two culverts under County Line

Road, the three miles of Willow Creek in Douglas County are in a completely

natural state. A water transmission main lies buried under the creek bed on

a line of extension of Yosemite Street. The channel is well defined, steep,

and mostly clear of brush and trees although short reaches are to be found

where willows are becoming established. Only small flood plains have been

formed at sharper bends of the creek. Three exposures of easily crumbled

sandstone were noted. Otherwise the waterway is formed of soft clayey

soils. They are bare of vegetal cover and erode during times of appreciable

runoff. Just below point 212, as shown on Chart 2, shallow grassed swales

give way suddenly to deep, bare gulleys with steep sides, the formation of

which advances upstream with each major rainstorm.

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