FLOOD08228

• County: Boulder
• Community: Boulder
• Stream Name: Boulder Creek
• Basin: South Platte
• Title: Urban Drainage and Flood Control District
• Date: 3/1/1990
• Prepared For: Boulder Creek
• Prepared By: Goerge V. Sabol
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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TABLE OF CONTENTS

Page

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

MODEL DEVELOPMENT........................................... 1

MODEL RESULTS............................................... 4

FLOOD FREQUENCY ANALySIS.................................... 4
COMPARISON OF MODEL TO FLOOD FREQUENCY RESULTS.............. 5
FINAL MODEL CONFIGURATION................................... 6
FLASH FLOOD PREDICTION GRAPH....................... . . . . . . . . . 7
HISTORICAL STORM RECONSTITUTION AND TRANSPOSITION........... 7
FLOOD DISCHARGES FROM TRANSPOSED STORMS..................... 11

REFERENCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

LIST OF TABLES
(following text)

1 Subbasin rainfalls, areas and percent imperviousness
2 Rainfall loss parameters for Various HEC-1 Runs
3 Unit hydrograph data and parameter values for each subbasin
4 Results of HEC-1 model for various input parameter combinations
5 Peak discharges at mouth of Boulder Canyon
6 Convective storm rainfall model output - Big Thompson, CO flash flood
(31 July 1976)
7 Convective storm rainfall model output - Cheyenne, WY flash flood
(1 August 1985)
8 Convective storm rainfall model output - Masonville, CO flash flood
(10 September 1936)
9 Summary of meteorOlogic observations
10 Peak 'discharges and times to peak for historic storms