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

I

I

Phase B. Preliminary Design

I

I

1. Prepare final hydrologic studies in hydrograph form to determine

the magnitude and volume of flood runoff for design purposes.

2. Develop design criteria for the selected plan.

3. Prepare topographic mapping having a 1" = 200' scale with a tw<)-

foot contour interval for plan and profile purposes and having a

I" = 100' scale with a two-foot contour interval for structure

and improvement drawings.

4. Develop channel and fl~od plain requirements and review them with

local officials.

5. Prepare plan and profile drawings of the stream channel and flood

plain, compJete with channel invert and flood profile water sur-

face elevations.

6. Prepare preliminary design drawings accompanied by a written re-

port presenting all data including a cost estimate of the work.

I

I

I

I

I

I

Only some 29 miles of major waterways were included in the scope of the

work. The many smaller tributaries in the basin were not specifically

treated, but their flows have been accounted for in the overall hydrolo-

gic analyses. Any flood proble.mn along the smaller tributaries fall out-

side of this study.

I

I

Phase A

Summary and Conclusions

I

The foregoing Phase A studies led to the development of five possible plans

for flood control along Little Dry Creek, as follows:

I

Plan A

I

I

I. Improve Englewood Dam to meet probable maximum precipitation

flood criteria.

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

Country Club golf course to pass 7,200 cubic feet per second.

3. Improve Cinderella Conduit to pass 7,200 cubic feet per second.

I
I

I

-5-