FLOOD05793

• County: Boulder
• Community: Longmont
• Stream Name: Dry Creek
• Basin: South Platte
• Title: Technical Addendum Floodplain Information and Flood Control and Drainage Plan
• Date: 4/1/1980
• Prepared For: Boulder County
• Prepared By: Water Resource Consultants
• Floodplain - Doc Type: Floodplain Report/Masterplan

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TABLE OF CONTENTS

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Page

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NOTE TO TECHNICAL ADDENDUM USERS

LOCATION

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HYDROLOGIC ANALYSIS

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Flood Characteristics
Method of Analysis
Dry Creek No.1 Peak Discharges
Rainfall Distribution
Drainage Areas
Subchatchment Data
Channel Data
Average Watershed Slope
Soils Data
Year 2000 Hydrology
Irrigation Ditches
Hydrology Effects of Irrigation Canals
Irrigation Ditches Effects on Peak Flows
Storm Intensity Input for Different Frequencies /
SWMM MODEL
SWMM Model Run / 100-Year Frequency

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2
4
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9
10
12
13
14
15
19
20
24

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25
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HYDRAULIC ANALYSIS

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General
Procedures
Sample - Structures Survey
Sample - Digitized Cross Section Plot
Determination of Manning N Values
Major Storage Reservoirs in the Basin
Example - Hydraulic Calculations
Input / Output HEC-2 runs for All Five Frequencies
Floodway Data
Floodway Delineation

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40
75
85
91
135
142

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DAMAGE ASSESSMENT

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Methods of Assessing Market Value
Flood Damage Assessment
Evaluation of Indirect Damages
Summary of Damages - DIS From S.H. 119
Summary of Damages - U/S From S.H. 119

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153
157
160
161

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