FLOOD01454

• County: Mesa
• Community: Grand Junction
• Stream Name: Colorado River
• Title: Colorado River Flood Analysis - A Proposal for Engineering Services
• Date: 11/1/1983
• Prepared For: Grand Junction
• Prepared By: Greenhorne & O'Mara, Inc.
• Floodplain - Doc Type: Project

COLORADO RIVER, FLOOD ANAL.YSIS

INTRODUCTION

Objectives

Mesa County and the City of Grand Junction require cel^tain hydrologic and
hydraulic information to manage flood warning, protection, evacuation, and
emergency response programs for conditions of high flow on the Colorado River
near Grand Junction, Colorado. The following items have been identified by
these agencies as project objectives:

. Obtain information to aid in monitoring and predicting flood levels in the
Colorado River.

. Obtain new floodplain information using recent aerial photographs of
flooding to check and update previous analyses.

. Obtain a flood hazard identification map that shows areas subject to
flooding, the magnitude of flow where flooding begins, and the extent of
flooding as the flow rates increase"

. Evaluate existing facilities and develop recommendations for improvements
that would mitigate flooding in high damage areas,

. Develop information that addresses the failure potential of upstream
reservoirs, the effect of a failure on the City, and the timing of the
flood wave.

SCOPE OF SERVICES

Introduction

The Request for Proposal solicits analysis, accumulation, and compilation
of hydrologic and hydraulic data for emergency response and flood improvement
programs. The scope of services in line with the budget pl"esented calls for a
hydraulic investigation of the Colorado River in a five and one-half mile study
reach, and just as important, research of existing information from Federal,
state and Local Agencies, and the assemblin~l of that information into a useful
format. With this in mind, the following program is recommended,

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