FLOOD01680

• Designation Number: 126
• County: Boulder
• Community: Unincorporated Boulder County
• Stream Name: St. Vrain Canyon upstream of Lyons
• Title: Floodplain Information Report - South St. Vrain Canyon upstream of Lyons, Boulder County, CO
• Date: 2/1/1978
• Designation Date: 1/1/1979
• Floodplain - Doc Type: Floodplain Report/Masterplan

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TABLE OF CONTENTS

Subject

LIST OF FIGURES

LIST OF TABLES

PREFACE

INTRODUCTION
Authorization
Purpose and Scope
Acknowledgements
Related Flood Studies

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STUDY AREA DESCRIPTION
Drainage Basin Characteristics
Study Reach Description

HISTORY OF FLOODING

HYDROLOGIC AND HYDRAULIC DETERMINATIONS
Flood Characteristics
Hydrologic Analysis
Hydraulic Analysis

INTERPRETATION AND USE OF REPORT DATA
Flood Frequency and Discharge
Flooded Areas
Flood Elevations
Control Markers

BIBLIOGRAPHY

GLOSSARY

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LIST OF FIGURES
Figure 1 St. Vrain Creek, May 9, 1957
Figure 2 1957 Flood, Railroad washout near Lyons
Figure 3 Lyons, Colorado, May 7, 1969
Figure 4 Flood of May 7-8, 1969 at Lyons
Figure 5 Lyons, Colorado, May 7, 1969
Figure 6 Discharge-Frequency Curves

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LIST OF TABLES

Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7

Drainage Areas

Historical Flood Peak Discharges and Stages

U.S.G.S Gaging Stations

Peak Discharges at Selected Locations

Roughness Coefficients

Flood Frequency-Elevation and Discharge Data

Control Markers Tabulation

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