Floodplain Stormwater & Criteria Manual

The Colorado Floodplain and Stormwater Criteria Manual (Statewide Manual) has been prepared to establish the minimum uniform standards for identification and designation of all floodplains within the state. The CWCB designates and approves the state's floodplains under the provisions of its "Rules and Regulations for Regulatory Floodplains in Colorado." The floodplain and floodway criteria outlined in the Statewide Manual are part of the CWCB Rules and Regulations.

Browse the Table of Contents and read the Executive Summary.

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Chapter 1 - General Provisions covers the following topics: 

Section 1 – Purpose
Section 2 – Applicability to Existing Drainage Manuals
Section 3 – CWCB Authority and Roles
Section 4 – Colorado Flood History
Section 5 – Applicable Drainage Laws
Section 6 – Definition of Terms and Acronyms

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Chapter 2 - Principles covers the following topics: 

Section 1 – CWCB Rules and Regulations
Section 2 – CWCB Operating Principles

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Chapter 3 - Floodplain and Stormwater Management covers the following topics:

Section 1 – Floodplain Management
Section 2 – Stormwater Management

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Chapter 4 - Permit Requirements covers the following topics:

Section 1 – Local Permits
Section 2 – State Permits
Section 3 – Federal Permits

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Chapter 5 - Report Submittal Requirements covers the following topics:

Section 1 – Revision of Existing Floodplains
Section 2 – Delineation of New Floodplains
Section 3 – Subdivision Drainage Submittals

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Chapter 6 - Flood Preparedness Activities and Flood Hazard Mitigation covers the following topics:

  • Authority & Responsibility
  • Existing Mitigation Plans, Programs & Structures
  • Mitigation Strategies

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Chapter 7 - Information Resources and Networks covers the following topics:

  • Floodplain Resources
  • Hydrology Resources
  • Hydraulic Resources

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Chapter 8 - Mapping Standards and Modernization covers the following topics:

  • Federal guidelines and specifications for flood hazard mapping partners

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Chapter 9 - Hydrologic Analysis covers the following topics:

Section 1 – Methods and Applications
Section 2 – Statistical Analysis
Section 3 – Regional Regression Analysis
Section 4 – Rainfall
Section 5 – Runoff
Section 6 – Mean Annual Flow Analysis

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Chapter 10 - Hydraulic Analysis covers the following topics:

Section 1 – Detailed Method
Section 2 – Limited Detailed Method
Section 3 – Approximate Method

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Chapter 11 - Floodplain Delineation covers the following topics:

  • Level of Study
  • Watershed Development Conditions
  • Flood Hazard Zone Designations
  • Detailed Floodplain Delineation Method
  • Limited Floodplain Delineation Method

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Chapter 12 - Unique Hydraulic Conditions covers the following topics:

Section 1 – Alluvial Fan Hazards
Section 2 – Mudflow, Debris Flow
Section 3 – Irrigation and Stormwater Interaction
Section 4 – Ice Jams
Section 5 – Drainageway Buffer Zones and Setback Limits
Section 6 – Two-Dimensional Modeling

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Chapter 13 - Hydraulic Analysis and Design covers the following topics:

Section 1 – Open Channels
Section 2 – Bridges and Culverts
Section 3 – Dams and Reservoirs
Section 4 – Levees
Section 5 – Detention Basins
Section 6 – Drop Structures
Section 7 – Recreational Structures

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Chapter 14 – Storm Drain Systems covers the following topics:

Section 1 – Storm Drains
Section 2 – Streets

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Chapter 15 – Storm Drainage Water Quality covers the following topics:

Section 1 – Stormwater Quality Management Principles
Section 2 – Best Management Practices

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Chapter 16 – References provides references for may of the topics within the manual.

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