FLOOD10516 ‎(2)‎

• County: Weld
• Community: Fort Collins
• Stream Name: Cache La Poudre River
• Basin: South Platte
• Title: Volume I - Hydraulic Analysis for the Cache La Poudre River between Timnath Diversion Dam and College Ave.
• Date: 4/11/2006
• Prepared For: Fort Collins
• Prepared By: Anderson Consulting Engineers, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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VOLUME I - TABLE OF CONTENTS

I.

INTRODUCTION ............................................................................................................1.1

1.1 Background.......................................................................................................... .1.1

1.2 Previous Studies..... ......... ........... ........ .................... ......... ......... ....... ...... ............... .1.4

1.3 Mapping............................................................................................................... .1.6

1.3.1 Effective Condition................................................................................... .1. 6
1.3.2 Existing Condition................................................................................... .1. 6
1.3.3 Revised Condition.................................................................................... .1.7

II. HYDROLOGY .................................................................................................................2.1

III. EFFECTIVE CONDITION HYDRAULIC ANAL YSES................................................3.1

3.1 FEMA Analyses..... .................. ..... ............................. ......... ....... ............... ......... ...3.1

3.1.1 Definition of Hydraulic Model/Modeling Reaches................................... 3.1
3.1.2 Starting Water Surface Elevations and Roughness Coefficients ..............3.3
3.1.3 Floodplain and One-Foot Floodway Results............................................3.3

3.2

COFC Analyses ........... ....... .... ..... ....... ......... .... ...... ..... ....... ..... .............. ....... ....... ..3.7

3.2.1 Definition of Hydraulic Model/Modeling Reaches ...................................3.7
3.2.2 Starting Water Surface Elevations and Roughness Coefficients ..............3.8
3.2.3 Tenth-Foot Floodway and Product 6 Corridor Results............................3.8

IV. DUPLICATE EFFECTIVE CONDITION HYDRAULIC ANAL YSES.........................4.1

4.1 FEMA Analyses....................................................................................................4.1

4.1.1 Floodplain Analyses and Results.............................................................. 4. 2
4.1.2 One-Foot Floodway Analysis and Results................................................4.5

4.2 COFC Analyses - Tenth-Foot Floodway Analysis and Results............................4.5

V. CORRECTED EFFECTIVE CONDITION HYDRAULIC ANALYSES .......................5.1

5.1 FEMA Analyses ........... .................... ..................... .............. ............ ........ ...... ..... ...5.1

5.1.1 Floodplain Analyses and Results................................................ .............. 5.1
5.1.2 One-Foot Floodway Analysis and Results................................................ 5. 6

5.2 COFC Analyses - Tenth-Foot Floodway Analysis and Results............................5.6

COFC2003.1O FINAL LOMR TOC.doc

ANdERSON CONsulTiNG ENGiNEERS, INC.