Study Guide to the Johnstone River Case Study on Flooding
The steps you need to follow for a real river system in order make
decisions about where and when it will flood and what you could do to
minimise the destruction
Coastal Queensland rivers can experience dramatic changes in levels
due to the torrential rain caused by cyclonic events.
Local goverments can act more effectively if they have a better idea of
the size and consequences of a particular flooding event.
This case study consists of selected material from a much more
comprehensive study by the Johnstone Shire.
It serves as an example of the steps needed to research, develop and
refine a response to flooding.
Step 1. Study of existing information and collect data
Step 5. Insert various plans for reducing flood impacts into the flood
From the design floods key areas that have a positive or negative impact
on the rapid drainage of water from the area can be identified: digging
out Carello's Channel
would clear a bottleneck in the Johnstone River; Webb
Levee protects the Central Business District; costly River
Dredging may be paid for in part by selling the fertile silt for
Levee is good for one residential area but not so good for another
residential area compromise may be achieved by Modifying
Shape of Carello's Levee ; in flooding the recently raised Bruce
Highway (the main north -south highway) facilitate vehicle movement but
causes local flooding as it acts as a damLowering
Height of the Bruce Highway would reduce this flooding but could
result in the highwy closing more often which would have an impact on many
communities in the region; the town swamp , having been filled in over the
years, has a reduced capacity to act as a holding area during flooding but
his could be reversed by Removal
from Town Swamp .
Step 6. Estimate the cost of flooding to the region