FLOOD00281

• County: Larimer
• Community: Greeley
• Title: Design Criteria and Construction Specifications volume 2 of 5 Storm Drainage Criteria
• Date: 10/1/1997
• Prepared For: Greeley
• Prepared By: Department of Public Works
• Floodplain - Doc Type: Educational/Technical/Reference Information

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TABLE OF CONTENTS

SECTION 1.0 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. I. I

Ll Purpose .. .. .. .. . . . . . . .. . .. . . . . . .. .. . . . . .. . . .. .. . . . .. .. .. . . .. . . . . . .. . .. I. I
1.2 Principles for Storm Drainage Planning & Design ............................. I. I
1.3 Comprehensive Drainage Plan. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.2

1.4 Irrigation Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. I. 3
1.5 Relationship to Other Standards ........................................... 1.3

1.6 Variances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.4
1.7 Review and Acceptance. . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . .. . . . . . . . . . . . . . . .. I - 4

SECTION 2.0 SUBMITTAL REQUIREMENTS .......................................... 2 - I

2.1 Review Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .. 2 - I
2.2 Conceptual Drainage Report .............................................. 2 - 2

2.2.1 Conceotual Reoort Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2 - 2
2.2.2 Conceotual Reoort: Plan Contents .................................. 2 - 4

2.3 Preliminary Drainage Report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2 - 5

2.3.1 Preliminarv Reoort Contents ....................................... 2 - 5
2.3.2 Preliminary Submittal: Plan Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2 - 8

2.4 Final Drainage Report .................................................. 2 - 10
2.5 Construction Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2 - II
2.6 Construction Certification & Drawings of Record ............................ 2 - 12

SECTION 3.0 RAINFALL ............................................................ 3 - I

3.1 Introduction. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3. I
3.2 Selection of Design Storm Frequencies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3. I
3.3 CUHF Design Storms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 - 3
3.4 Intensity-Duration-Frequency (IDF) Cwvcs .................................. 3 - 3

SECTION 4.0 RUNOFF ANALYSIS ................................................... 4 - I

4.1 Introduction.. .. .. . . . . .. . .. . . . . .. . . . . . . . .. . . .. .. . . . .. . .. . . . . . . . . . . . . . .. 4 - I
4.2 Rational Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4 - I
4.3 Colorado Urban Hydrograph Procedure (CUHP) .............................. 4 - I
4.4 Storm Flow Analysis .................................................... 4 - 2

4.4.1 On-site Flow Analvsis ............................................ 4 - 2
4.4.2 Off-site Flow Analvsis ............................................ 4 - 2
4.4.3 Tributarv Area Within a Maior Drainagewav Basin ..................... 4 - 2

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