FLOOD10157

• Designation Number: 74
• County: Arapahoe
• Community: Aurora
• Stream Name: Granby and Sable Ditches
• Basin: South Platte
• Title: FHAD - Granby and Sable Ditches, Aurora, Colorado
• Date: 4/1/1977
• Designation Date: 7/27/1977
• Floodplain - Doc Type: Floodplain Report/Masterplan

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

TABLE OF CONTENTS

TABLE OF CONTENTS - Continued

Page

PREFACE

Authorization
Purpose and Scope
Acknowledgments

1
1
1.
2

LIST OF TABLES

Page

STUDY AREA DESCRIPTION

2

Table I - Drainage Areas 3

Table II - Future Land Use Data 4

FLOOD HISTORY

3
3

Table III - Rainfall Data 4

Table IV - Basin Parameters 5

Table V - Design Point Peak Discharges 5

FLOOD RELATED STUDIES AND OTHER PERTINENT DATA

HYDROLOGIC AND HYDRAULIC DETERMINATIONS

Hydrologic Analysis
Hydraulic Analysis

4
4
6

Table VI - Flood Plain and Floodway Reference
Data - Sable Ditch Appendix A-6

Table VII - Flood Plain and Floodway Reference
Data - Granby Ditch Appendix A-8

FUTURE FLOODS

Flood Frequency and Discharge
Flooded Areas
Sable and Granby Ditches - Below Confluence
Flood plain and Floodway Data
Flood velocities

6
6
6
7
10
10

LIST OF FIGURES

SUMMARY

10

Figure 1 - Granby Ditch Above Sable Ditch Confluence
(lO-year, 100-year flood hydrographs)

11

Figure 2 - Sable Ditch Above Granby Ditch Confluence
(lO-year, 100-year flood hydrographs)

BIBLIOGRAPHY

APPENDIX

12

Figure 3 -
Figure 4 -
Figure 5 -
Figure 6 -

DRAWINGS

22

Granby Ditch at Colfax Avenue
(lO-year, 100-year flood hydrographs)

Sable Ditch at Colfax Avnnue
(lO-year, 100-year flood hydrographs)

Below Confluence of Granby and Sable Ditch
(lO-year, 100-year flood hydrographs)

Granby Ditch at Laredo Street
(lO-year, 100-year flood hydrographs)

Figure 7 - Discharge Probability Profiles
Sable Ditch

Figure 8 - Discharge Probability Profiles
Granby Ditch

Appendix A-I
Appendix A-I
Appendix A-2
Appendix A-2
Appendix A-3
Appendix A-3
Appendix A-4
Appendix A-5