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

I

20

I

I

Erosion and Sedimentation Potential Study on Sand Creek in Aurora

Sand Creek flows in a predominantly northwest direction through the City

of Aurora, Colorado, before discharging into the South Platte River. The

drainage basin is long and narrow and has an area of approximately 189 square

miles. Due to urbanization, Sand Creek has been encroached upon, causing

significant changes and problems between Peoria Street and Chambers Road in

Aurora, Colorado. The most significant change in the system has been chan-

nelization, resulting in degradation because Sand Creek is a sand-bed channel.

An analysis of the potential aggradation and degradation was conducted to

determine design criteria to insure the stability of existing and planned

I

I

I

I

structures.

I

The equilibrium slope method was used in this analysis. With this

method, by knowing the hydraulic conditions and the sediment size distribu-

tion, an equilibrium channel bed slope can be determined. This is the slope

at which the channel can transport only the volume of sediment that is being

supplied from upstream and therefore, eliminates degradation.

To control the degradation problems, the channel design slope along with

I

I

the number of required drop structures was determined. A series of low drops,

I

which will act as grade controls, was recommended for the study reach, to

increase public safety, general appearance, ease of maintenance, and because

I

the cost to construct the drops is low.

Project period: December 1980 through March 1981

Project Budget: $6,000

Reference: Mr. Ben Urbonas
Chief, Master Planning Program
Urban Drainage and Flood Control District
2480 West 26th Avenue
Denver, CO 80211
[phone]

I

I

I

Mr. Charlie Carroll
Director of Utilities
City of Aurora
1470 South Havana
Aurora, CO 80012
[phone]

I

I

I
I.