FLOOD06925

• County: Larimer
• Community: Greeley
• Stream Name: Cache La Poudre River
• Basin: South Platte
• Title: Master Floodway Planning
• Date: 3/11/1983
• Prepared For: Greeley
• Prepared By: Simons Li & Associates Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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24

Erosion and Sedimentation Study for Toll Gate Creek, Aurora, Colorado

Toll Gate Creek flows in a northerly direction through the City of

Aurora, Colorado, to its discharge point at Sand Creek. The area of the basin

is approximately 39 square miles. Due to severe flood damage in the past and

increasing urban development between Sixth Avenue and Sand Creek, a chan-

nelization design has been proposed to reduce the flood potential. Such a

design must consider the erosion and sedimentation problems that may develop.

This study was conducted to establish design criteria for the proposed

channelization to minimize the erosion and sedimentation problems. Among the

potential problems are bank erosion and lateral migration, channel bed degra-

dation, low-flow channel development, and local scour at bridges. By

reviewing the history of Toll Gate Creek and analyzing the "as-is" conditions,

a qualitative determination of the response of Toll Gate Creek to the proposed,

channelization was made. This was then verified by the equilibrium slope

method. This method determines the design channel bed slope at which the

channel is in equilibrium. In addition, the response of the proposed chan-

nelization to future urbanization was analyzed.

The results of the study included recommendations on design channel

slope, channel geometry, type of bank protection, depth of bank protection,

and required grade control structures.

Project Period: September 1981 through December 1981

Project Budget: $20,000

Reference: Mr. Douglas C. Weber, P.E.
Project Engineer
Centennial Engineering, Inc.
15000 West 64th Avenue
Arvada, CO 80004
[phone]