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