FLOOD01117

• Designation Number: 219
• County: Arapahoe
• Community: Littleton
• Stream Name: Upper Slaughterhouse Gulch
• Title: Major Drainageway Planning - Upper Slaughterhouse Gulch
• Date: 3/1/1983
• Designation Date: 7/1/1983
• Floodplain - Doc Type: Floodplain Report/Masterplan

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CHAPTER VI - RESULTS AND RECOMMENDATIONS

REACH-D
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2.

(Caley Avenue to Denver Highline Canal)
IOO-year detention facility
Denver Highline Canal spill structure

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A. General

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The purpose of the Major Drainageway Planning study for the Upper Slaughter-

house Gulch Basin was to delineate the drainage problems, evaluate several alterna-

tives for reducing flood damages, determine the best alternative plan using economic,

legal, and environmental criteria, and prepare preliminary design drawings for the

selected alternative plan. The drawings are subsequently used to regulate the

floodplain plan for future development, and identify needed improvements. The

results and conclusions of the study are:

REACH-E (Denver Highline Canal to Arapahoe Road)
I. 5-year storm sewer

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As part of the selected alternative plan, the following recommendations are
also made:

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J. The delineated IOO-year floodplain should be adopted and regulated.

2, Subsequent to implementation of the alternatives, the residual floodplain,

as shown on the drawings, should also be regulated.

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B. Selected Alternative

3. The purchase of flood insurance for those properties within the IOO-year
floodplain should be encouraged.

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The recommendations of improvements in the Phase-A study were reviewed by the

City of Littleton, Arapahoe County, and the Urban Drainage and Flood Control Dis-

trict (UD&FCD). The recommendations were accepted by all entities for Phase-B

preliminary design with some additions and modifications,

4. Adequate maintenance access (a minimum flat surface width of IO-feet) should
be provided to all facilities.

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5. Adequate erosion control measures should be included for all channel improve-
ments and structures.

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The selected alternative plan (see Figure V-I) is basically a combination of

storm water detention and major conduit. The selected alternative is described in

detail in Section V-A of this report and the major components are summarized below.

6. New development within the watershed should provide on-site erosion control

during construction to limit the amount of siltation in the drainageway

during frequent runoff events.

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REACH-A
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(Powers Park to Littleton City Limits)
5-year storm sewer

7.

Purchase or dedication of drainage easements which will be necessary for
implementing the drainageway improvements.

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REACH-B (Littleton City Limits to Grant Street)
I. 5-year channel

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C. Improvement Costs

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REACH-C (Grant Street to Caley Avenue)

I. 5-year storm sewer

2. Local collector from Pennsylvania Street to Clarkson Street

3. Local collector along Grant Street from Caley Street to Pennsylvania Street

A detailed cost estimate of the improvements for the selected alternative plan

was prepared for the master plan drawings. The costs were divided into the following

categories:

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