This course describes the skills you require to understand the hydrology, hydraulic and statistical computations needed to select and analyze flood protection and stormwater control alternatives. The course aims to make sense of this complex topic and to assist in selecting the best approach. It focuses on the practical application of sound planning and design practices, and specific flood control and stormwater management techniques while exposing you to emerging practices.

Emphasis will be on demonstrating the pros and cons of alternative design and implementation strategies, the pitfalls that should be avoided, and the design features that characterize successful systems.

Course Outline 

1. Flood Control Advantages and Disadvantages
2. Selection of Design Criteria for Flood Control
3. Methods of Computing Flows Based on Rainfall
4. Hydraulic Modelling of Flows and Flood Levels
5. Flood Plain mapping
6. Land drainage
7. Alternative Urban Stormwater Best Management Practices
8. How to Select Stormwater Best Management Facilities
9. A brief review of drainage design computer software

Who should attend?

• Municipal Engineers and Technologists
• Civil Engineers and Technologists
• Developers
• Planners
• Consultants
• Approval Agency Staff and Other Technical Personnel Responsible for Flood Control and Drainage Projects

After participating in this course you will be able to do the following;

• Selecting and estimating design events,
• Apply new techniques to enhance the protection of life and property from flood damage select computer software for application in flood control and urban drainage design
• Be familiar with decisions policymakers, agency staff and designers have to make
• Apply emerging techniques for stormwater quantity, quality, and erosion control
• Broaden your understanding of the fundamental hydrology and hydraulic issues
• Strengthen your skills in flood control and urban drainage system design

DAY ONE | Flood Control

Overview of Flood Control Alternatives, Advantages, and Disadvantages

Modify the Flood by Structural Control

• Dams
• Reservoirs
• Levees
• Channel improvements
• Diversion
• Stormwater Management

Digital Transformation Modify the Flood By Non-Structural Control

• Watershed treatment
• Forestation
• Removal of debris jams

Modify the Susceptibility to Damage by Structural Method

• Floodproofing
• Elevate structures
• Relocation

Modify the Susceptibility to Damage by Structural Method

•  Flood proofing
• Elevate structures
• Relocation

Modify the Susceptibility to Damage by Non-Structural Method

• Redevelopment
• Flood forecasting
• Evacuation
• Emergency measures

Modify the Loss Burden

• Flood insurance
• Rehabilitation

Selection of Design Criteria for Flood Control Flood control criteria are based on:

• Return period event derived by statistical analysis
• Observed flood or storm
• Concept of risk in the selection of design criteria
• Design criteria for flood control for developed and undeveloped areas
• Design criteria for hydraulic structures

DAY TWO | Computing Flows

Overview of Methods of Computing Flows Based on Rainfall

• Data preparation, IDF curves, statistical frequency analysis
• Rainfall abstractions, Runoff coefficients, SCS CN, Antecedent conditions
• Time of concentration, Various method comparison
• Peak flow calculations
• Rainfall distribution, Design hyetographs
• Hydrographs and Unit hydrographs
• Effect of development on runoff
• Examples and sensitivity analysis
• Effect of climate change
• Computer assisted flow calculations

Overview of Methods of Computing Flows based on Recorded Flow

• Data length
• Homogeneity of data
• Statistical analysis
• Regional analysis of streamflow to estimate flood discharges

Hydraulic Modeling of Flows and Flood Levels

• Selection of models
• Review of HEC-RAS backwater model

Flood Plain Mapping

• Preparation of base maps, topographic data, surveys
• Implementation of development control using flood plain maps & flood and erosion control policies
• One and two-zone concepts
• Valley system approach and development setbacks

DAY THREE | land Drainage and Stormwater Management

Why Do We Need Stormwater Management

• Change in peak flows and runoff volumes
• Change in water quality
• Change in groundwater recharge
• Change in stable river syste

Land Drainage – Basics

• Perimeter open field ditches
• Infield subsurface drainage pipes
• Banks or embankments
• Water pumps, water control structures: sluices, weirs & dams

Alternative Urban Stormwater Best Management Practices

• Lot controls (Roof leaders, rooftop storage, landscaping, lot grading, porous paving)
• Conveyance controls (Grassed swales, previous pipes, filters, infiltration, bioretention)
• End of Pipe controls (detention ponds, wetlands, underground chambers, oil and grit separators)
• Miscellaneous controls (litter control, street sweeping, road salt management, public education)

How to Select Stormwater Best management Facilities 

• Major-minor system design
• A review of the most frequently used control practices
• Review of latest technologies, (porous pavement, green roofs, bio-retention, etc.)
• Low Impact Development

Brief Review of Drainage Design Computer Software

• Model complexity
• Selection of software

WORKSHOP –  Example of Stormwater Management Design For an Urban Infill Area