FLOOD02508

• Designation Number: 292
• County: Adams
• Community: Westminster
• Stream Name: Big Dry Creek
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Bruchez Farms Property, Big Dry Creek at Wadsworth Parkway
• Date: 1/1/1988
• Designation Date: 3/1/1988
• Floodplain - Doc Type: Floodplain Report/Masterplan

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23

completed Ketner Reservoir improvements, the hydraulic characteristics of the

existing C&S railroad culvert, and only that storage which exists within the

floodway upstream of the railroad, the water surface elevation Immediately

upstream of the railroad culvert is decreased to 5358.2 from the water surface

elevation of 5365.0 reported in the 1986 study.

12. Based on this more In-depth study, there is a reduction of 6.8 feet in the eleva-

tion of the 10o-year floodplain for the land located between the C80S railroad and

Wadsworth Parkway, both north and south of Big Dry Creek.

13. Based on the water surface proflles generated by the HEC-2 program, using as

Input data the results of the HEC-l modeling, the water surface elevation just

upstream of Wadsworth Parkway Is 5359. O. This Is a reduction of 6.0 feet

from the 1986 FHAD study and leaves most of the Bruchez property outside of

this revised tOO-year floodplain.

14. The proposed Master Plan for Big Dry Creek envisions four 120-inch reinforced

concrete pipes to be placed under the C80S Railroad in addition to the existing

concrete arch culvert. This additional ouflow capacity will reduce the water

surface elevations to an even greater extent than indicated In this study. There-

fore, when the Master Plan Is implemented, almost all of the Bruchez property

will be located outside of the flOOdplain.

15. The newly published FEMA flood insurance study for Big Dry Creek indicates that

the lOa-year floodplain elevations proposed in this stUdy are equal to or

greater than the elevations shown in the FEMA study for this reach of Big Dry

Creek.