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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Plan B

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1. Improve Englewood Dam to meet probable maximum precipitation

flood criteria.

2. Build five additional flood detention dams.

3. Improve drainage channel from South Platte River to Cherry Hills

Country Club golf course to pass 4,700 cubic feet per second.

4. Improve Cinderella Conduit to pass 4,700 cubic feet per second.

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Plan C

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1. Improve Englewood Dam to meet probable maximum precipitation flood
criteria.
2. Build five additional flood detention dams.

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Plan D

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1. Improve Englewood Dam to meet probable maximum precipitation
flood criteria.

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Plan E

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1. Improve Englewood Dam to meet probable maximum precipitation
flood criteria.
2. Build five additional flood detention dams.
3. Improve Little Dry Creek channel from South Platte River up to its
confluence with Greenwood Gulch to carry 4,700 cubic feet per second,
and 1,300 feet above its confluence with Greenwood Gulch to carry 3,100
cubic feet per second.
4. Improve Greenwood Gulch from its confluence with Little Dry Creek
1,400 feet up to carry 2,400 cubic feet per second.
5. Improve existing upper reach of Cinderella Conduit to convey 4,700
cubic feet per second.
6. Extend Cinderella Conduit from existing entrance up to Sherman
Street bridge.

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Preliminary cost estimates were made for each of the alternative plans. In
order to compare the benefits to be derived from these plans with their
costs, the net present worth method was used over a 25-year municipal bond
payback period and a 50-year project life expectancy with a 5.5 percent in-
terest rate. The following ranking of plans was obtained:

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