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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C I N D ERE L L A

CONDUIT

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Little Dry Creek flows are presently carried in an underground concrete

box conduit from a point just south of E. Girard Avenue to a point just

west of the intersection of S. Huron Street and W. Eastman Avenue as

shown on Drawing 4. Construction of the conduit was started in 1966 and

was completed in 1969. Its intended purpose is to carry flows in Little

Dry Creek safely past the Cinderella City shopping center area. Its phy-

sical characteristics are as follows:

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Width of Miter Bends
l2 ft. Total Ground
Length High Box Deflection Slope Cover
Reach ft ft No. Degrees ft/ft ft
Entrance 510 15 1 22 0.0100 1 to 3
Middle 2150 l8 3 119 0.0060 1 to 4
Exit 582 18 2 77 0.1050 1 to 4
3242

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The entrance to the conduit has reinforcing bars projecting from its top

and walls to accommodate upstream extension in the future. A number of

storm drains are connected to the conduit to drain the Cinderella City

area. Flap gates were placed inside the conduit to prevent flood waters

from backing up in the storm drain system. These flap gates have been

damaged by debris in high velocity water flow in the conduit and they

are presently inoperative. Flap gates cannot be maintained in operating

condition in their present vulnerable locations. No energy dissipating

structure has been provided at the lower end of the conduit and the Little

Dry Creek channel at the conduit exit was heavily eroded by high velocity

flows from the conduit during the May 1973 storm.

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Present Capacity

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The maximum discharge capacity of the Cinderella Conduit is estimated to

be 3,000 cfs under 100-year flow conditions that produce a 7,lOO cfs total

flood peak. These flood conditions are those for future watershed

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