FLOOD01452

• County: Larimer
• Community: Fort Collins
• Stream Name: Fossil Creek Drainageway Basin
• Title: Master Drainageway Planning Study
• Date: 8/1/1982
• Prepared For: Larimer County
• Prepared By: Simons Li & Associates Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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1.

INTRODUCTION

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1.1

Objectives
The objectives of the master drainageway plan are:

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1. To provide a sound technical basis for the management of floodplains
by structural or nonstructural methods within the stuqy area.

2.

To reduce the threat to human life, personal injury, or related
health hazards due to floods.

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3.

To reduce or prevent flood damage and maintenance requirements for
public and private property and facilities.

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4.

To make effective use of public funds and to enhance the value of
land and other property within the study area.

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5.

To formulate and evaluate alternative flood control and drainage
concepts and to determine the most economically feasible and prac-
tical plan for mitigating the flooding problems for the study area.

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1.2 Purpose and scope

This report was prepared to guide local officials in planning the use and

regulation of the flood plain areas such that flood hazards and future damages

are eliminated or minimized. It includes information on historical floods,

existing factors which influence the flood hazard, the nature and extent of

probable future floods, and the related sedimentation and erosion problems.

This report also includes maps delineating flooded areas for the 100-year

flood boundaries and flood profiles showing the high water elevations for the

10-, 50-, 100-, and 500-year floods along the study reaches.

This study evaluates structural and nonstructural improvement plans to

mitigate or alleviate flood hazard areas and presents a plan to guide future

flood plain development in the study area. A supplement to this report in the

form of a technical addendum includes the supporting engineering and hydrolo-

gic data which may further be used in engineering studies in the location and

design of roads, bridges, and channel modifications.

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1.3 Authorization
This report was authorized by the Colorado Water Conservation Board in
joint sponsorship with the City of Fort Collins and Larimer County, Colorado.
The Board's power and duty is...

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II.. .to devise and formulate methods, means and plans for bringing
about the greater utilization of the waters of the state and the
prevention of flood damages therefrom and to designate and approve
storm or floodWater runoff channels or basins, and to make such
designations available to legislative bodies of cities and incor-
porated towns, to county planning commissions, and to boards of
adjustment of cities, incorporated towns, and counties of this
state.. .n

as stated in Section 37-60-106(c) of the Colorado Revised Statutes (1973).

The cities, incorporated towns, and counties within the study area may

provide zoning regulations...

". . .to establish, regulate, restrict, and limit such uses on or
along any storm or floodwater runoff channel or basin, as such storm
or floodWater runoff channel or basin has been designated and
approved by the Colorado water Conservation Board, in order to
lessen or avoid the hazards to persons and damage to property
resulting from the accumulation of storm or floodWaters..."

as stated in Section 30-28-111 for county governments and Section 31-23-201

for municipal governments of the Colorado Revised Statutes (1973).

Therefore, upon official approval of this report by the Colorado water

Conservation Board, the areas described as being inundated by the 100-year

flood (Intermediate Regional Flood) can be designated as flood hazard areas

and their use regulated accordingly by the local agencies. The terms

"Intermediate Regional Flood", 11100-year flood", and 1I0ne percent flood" can

be used interchangeably, as they define the same flood. However, to avoid

confusion, the term "100-year flood" will be used exclusively throughout this

report.

1.4 AcknOWledgements

A Technical Committee was established for this project to review the

progress of the study and to provide technical input. The Technical Committee

included the following individuals:

Mr. Robert Smith, City of Fort Collins, Colorado

Mr. Rex Burns, Larimer County, Colorado

Mr. Larry Lang, Colorado water Conservation Board

Mr. Randy Seaholm, Colorado Water Conservation Board

The assistance and cooperation of this committee during the course of this

study is acknowledged and is greatly appreciated.