2007 Hunter Valley floods

Storms surges and torrential rain are the most common reason for floods to develop.                                                                                                                                                                                                                                                                                                           A storm surge is a high flood of water caused by wind and low pressure. This high flood of water usually breaks the banks of rivers and seas to then flood low lying coastal regions. Torrential rain is another aspect which can severely flood an area; torrential rain is common during storm surges.                                                                                                                                                                                                                                                                                                                  As storm surges and torrential rain are the main cause of flooding, when they both act simultaneously they work together to provide the most devastating outcome of flooding.                                                                                                                                                                                                                                                                             When these processes are at work, they change the environment dramatically.

Torrential rain and storm surges operate simultaneously to dramatically change the environment.                                                                                                                                                                                                                                                                                            The flash flooding caused by the processes at work can be devastating. Many dry rivers in the Hunter Valley travel through roads, within minutes these rivers and roads can be fully submerged. Source 7 confirms how quickly and devastating these floods can be.                                                                                                                                                                                                                                                                                                             Many of the rivers in Hunter Valley flooded like this. Fortunately the main Hunter river didn’t break its banks; this could of lead to another 1955 flood. After the floods, erosion in the rivers would have been huge, causing environmental damage.                                                                                                                                                                                                                                                                                                           As shown in source 7 below, flooding can change the environment in a matter of minutes and cause great destruction.

With the help of both processes (torrential rain and storm surges) cause the creation of dangerous floods.                                                                                                                                                                                                                                                                                                                An intense low pressure system developed off the coast of New South Wales. This low pressure system resulted in several storm surges and rainfall that exceeded 300mm in only 36  hours.                                                                                                                                                                                                                                                                                                                Both processes occur during the intense low pressure system, both processes contribute equally to the flooding. Storm surges are the reason for the beaching of the MV Pasha Bulker as they failed to heed a warning to move out to sea.                                                                                                                                                                                                                                                                                                                Despite both processes being related, storm surges affected mostly the coastal areas while torrential rain flooded inland regions and mountainous areas.

The two processes greatly become an issue shortly after they develop.                                                                                                                                                                                                                                                                                                      Time is the main reason for these processes to become an issue. Once the low pressure system has developed, torrential rain will start with small amounts of rain, gradually this rain will increase in intensity storm surges will also start to occur. New South Wales Premier Morris Iemma declared a natural disaster for the affected areas.                                                                                                                     

                                                                                                                                                                                                                                                                                                                    Once the state government has declared a disaster, local council and media broadcast warnings and precautions to the public to stay indoors and possibly evacuate.                                                                                                                                                                                                                                                                                                  Once the issue was declared a disaster, evacuation procedures where taken when the Hunter River was close to breaking its banks. Luckily the evacuation was successful although the river didn’t burst its bank.