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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Master Drainageway Planning Study for Fossil Creek and Four Tributaries
A master drainageway planning study for Fossil Creek and four tributaries
was undertaken for the City of Fort Collins, Larimer County and the Colorado
Water Conservation Board. The scope of work for this study required an engi-
neering investigation for the determination of flooding problems and planning
of alternate drainage improvements for the Fossil Creek Basin. There were 15
miles of channel included in the study. The basin is approximately a 30
square mile rural watershed south of Fort Collins which is expected to
experience urbanization in the near future.
Hydrologic modeling of the watershed for existing and developed con-
ditions was based on the Storm Water Management Model (SWMM). Hydraulic
analysis to determine water surface profiles for different floods was based on
HEC-II. The subsequent aspects of the project involved flood damage
assessment, formulation of alternate improvement plans to reduce flood dama-
ges, preliminary design of each improvement plan and an economic evaluation of
each improvement plan to select the most economically beneficial alternative.
An additional task in this study required a stability analysis of road embank-
ments to be used for pending flood waters and channel banks which are
sloughing.
Project Period: November 1981 through August 1982
Project Budget: $30,000
Reference: Mr. Robert Smith
City of Fort Collins
300 Laporte Avenue
P.O. Box 580
Fort Collins, CO 80522
[phone], Ext. 728

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