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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sprinkled and mowed to maintain healthy sod. Costs of sodding, sprinkling

and mowing are examples of costs that should be borne by the developer.

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The Douglas County drainage channels along Willow Creek, Cook Creek,

and Spring Creek are not urbanized and channelization is not recommended.

Because of gullying and soils erosion that is occuring near the upper

ends of these waterways and their tributaries, hydraulic control struc-

tures may be justified. Drop structures at strategic locations would

significantly reduce soils erosion and may therefore be desirable.

A baffled apron chute drop structure suitable for this purpose is shown

on Drawing 36. Such drop structures are not, however, included in the capital

improvements proposed herein, as costs exceed benefits for these structures at

this time. The construction of these should be reconsidered as the area is de-

veloped.

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In Arapahoe County, urbanization has occured on Upper Little Dry Creek

east of Quebec Street and in Little Dry Creek upstream of the Highline

Canal. In both areas, the developers have modified the natural drainage

channels along their properties. No channelization is recommended using

public funds in Arapahoe County.

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Greenwood Village urbanization has not significantly encroached on the

natural waterways. If the flood plains along Little Dry Creek, Greenwood

Gulch, and Prentice Gulch are effectively zoned, channelization is not

required.

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In Cherry Hills Village channelization is recommended in two locations;

(1) from Greenwood Gulch along City Ditch to make a new confluence

with Little Dry Creek, and (2) on Little Dry Creek above and below

its new confluence with Greenwood Gulch.

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The Greenwood Gulch channelization in Cherry Hills Village extends about

1500 feet upstream from its confluence with Little Dry Creek as shown on

Drawing 12. This improved channel has sufficient capacity to prevent lOO-year

flood flows, as reduced by the additional detention dams, from spilling

into the old Greenwood Gulch channel to the west. Two bridges and a

City Ditch flume will be required across the Greenwood Gulch channel.

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