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Floods – In My Backyard?

Each year in Australia, floods cause millions of dollars damage.

Flooding affects buildings and critical infrastructure, such as roads and railways as well as to agricultural land, livestock and crops.

Floods also cause major disruptions to business and can affect the health of communities. Sometimes towns can be cut-off, causing people to be evacuated and emergency services will need to begin relief efforts.

Community flood prevention and reduction

Many communities have flood prevention or reduction strategies such as:

• Restricting the building of houses on floodplains
• Use of dams
• Building of levees and flood diversion devices
• Flood-proofing homes
• Raising homes and businesses in known flood areas.

It is important to know your local flood history. Knowing your local flood plan, when you may need to evacuate and how to get to your nearest safe location can save lives.

Flooding in Australia

Floodwaters can affect many Australian towns, areas and even cross borders. Here are some of Australia’s biggest floods.

Queensland - Brisbane, 1974

Flooded houses in Brisbane

This major flood was caused by the weakening Cyclone Wanda which crossed the Queensland coast 150 kilometres north of Brisbane on 24 January 1974. The cyclone caused only minor wind damage, but created heavy rains over Brisbane for a further 5 days.

Rainfall and record flooding

Before Cyclone Wanda came ashore, there was already some flooding in and around Brisbane. Among the highest rainfall recordings were 1,318mm (1.3 metres), whilst in Brisbane itself 819mm of rain fell. Many houses bordering rivers and creeks were washed away as rivers rose to their highest levels since the disastrous 1893 floods.

Flood damage, injuries and deaths

16 people died and 300 people were injured. 8,000 people were made homeless and 56 homes were swept away. 1,600 homes were submerged by the floodwaters and a total of 13,000 buildings were affected.

At the height of the flood, even ships were torn from their moorings. A large oil tanker on the Brisbane River was damaged and the total damage bill was estimated to be around $980 million.

The Great Floods – New South Wales, Queensland and Victoria, 1990

The 1990 floods in eastern Australia were huge. The total area flooded was estimated to be more than 1 million square kilometres. That’s an area larger than some countries – like Germany.

Rainfall, river systems and flooding

In central-northern NSW and central-southern QLD, continual heavy rains partly caused by cyclones, drenched the flat inland plains. Then further torrential rainfalls created almost instant floods. Many rivers had already flooded once and were in flood again, this time at even higher levels.

The many flooded river systems around northern NSW and southern QLD made flood height prediction difficult. Residents of Nyngan, on the Bogan River, strengthened levee banks in expectation of a record flood height, but the flood waters exceeded the levees. Almost every building in the own was flooded. Almost 2,500 people were evacuated, mainly by helicopters, under emergency conditions as all town services were lost.

Flood damage, injuries and deaths

Across the three affected States, the Great Floods of 1990 claimed 7 lives, caused 60 injuries and left 5,000 people temporarily homeless. The total estimated cost of these floods was $415 million (1997 values). Most of this damage was insured.

Road and rail links were severed for a long time and many residents could not return to their homes for three weeks or more. A huge 'tent city' was established at the Charleville Airport after the hospital had to be evacuated. More than 2000 residents were evacuated by boat and by air evacuation (mainly by helicopters).

New South Wales – Coffs Harbour, 1996

Flash flood in Coffs Harbour

A devastating flash flood hit Coffs Harbour when 168mm of rain (and up to 300mm in the area) fell within 2 hours on 25th November 1996.

Flash flooding

The November 1996 flood caused widespread devastation to property located on low-lying land beside the Coffs Creek. Around 260 residential homes and 200 commercial properties were inundated above floor level during this flash flood.

Flood damage, injuries and deaths

One woman died when she was swept more than one kilometre from her home and into the sea. 300 people had to be evacuated as over 500 homes and 100 businesses were damaged. The flood caused extensive damage to roads and a natural disaster was declared with more than 800 properties flood affected. Part of the local banana crop was also destroyed due to erosion and landslides. The damages were estimated to be more than $140 million.

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