Johnstone River Flooding

Unit 4 Case Study - The  Johnstone River, Far North Queensland

When Good Rivers Turn Bad Contents

Case Study Area is Located around Innisfail in Far North Queensland
(only selected parts of the Johnstone Shire flood study are provided courtesy of the Johnstone Shire Council)

Flood Warning System for the JOHNSTONE RIVER
Johnstone River Catchment
Flood Risk
Previous Flooding
Flood Forecasting
Johnstone River ALERT System
Flood Warnings and Bulletins
Telephone Weather Products
Interpreting Flood Warnings and River Heights
Assessment of the Flood Potential
Background to Flood Study
Background - the Johnstone River System
Objectives of the Flood Study
The Seven Key Stages in the Study
Flood Model Development and Calibration
How to Make a Flood Model
Comparing Model and Actual Rainfall at Innisfail
Design Floods -Hypothetical Floods Used for Planning
Calibrating the Flood Model example 1999 flood
Design Hydrology
The two main methods of determining the magnitude of the flow for a design event
Method 1. Flood frequency analysis (FFA)
Method2. Design rainfalls with the URBS Model
General Agreement between the two Models
Historical Evidence of Flood Levels
Ultimately Which River Levels Constiute a Flood is a Human Decision based on Both Models and Historical Evidence
Adopted Peak Flows - A Human Decision
Maps Showing Flood Predictions
Once in Two Year Flood
Once in Five Year Flood
Once in Ten Year Flood
Once in Twenty Year Flood
Once in Fifty Year Flood
Once in One Hundred Year Flood
Theoretical Maximum Flood
Some Possible Flood Mitigation Strategies
Constructed Carello's Channel
Webb Levee
River Dredging
Removal of Carello's Levee
Removal of Fill In Town Swamp
Lowering the Height of the Bruce Highway
Modifying the Shape of Carello's Levee
Dredging the River Channel
Impact of Carello's Levee on Once in Two Year Flood
Impact of Carello's levee on Once in Ten Year Flood
Flood Damage Assessment
The Effects of Flooding on the Local Economy
Rural Damages
Urban Damages
Infrastructure Damages
Intangible Damages
Summary Total Cost Including 1 in 100 year floods
Summary including possible maximum flood
Economic and Environmental Considerations
The Benefits of the Construction of Flood Modification Measures
Present worth of Annual Benefits
The Present Worth Factor
The Procedure for Calculating Benefit-cost Ratios
Environmental Considerations
Flood Hazard Catagories
Choosing Flood Hazard Categories
Recommended Approach
Flood Hazard Definitions
Local Area Hazard Map
Flood Warning and Emergency Planning
Public Information Campaign
How to Initiate a Public Information Campaign on Flooding
Johnstone River Probable Maximum Flood (PMF)
Estimated Probable Maximum Precipitation
Estimate Peak Probable Maximum Flows
Public Flood Totem (showing flood levels)
Probable Maximum Flood
Glossary of Flooding Terms

Case Study Tasksheet -open ended task
Flooding - Web based Activities


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