Does El Niño reduce my flood risk?

There is a common perception that once the current weather pattern moves from La Niña to El Niño (the ENSO cycle), the flood risk that the eastern states of Australia have been facing will pass.

Is the sigh of relief warranted?

The Bureau of Meteorology has released its long-range forecast which shows we are still in an active La Niña phase, with models indicating a move towards neutral or El Niño status.

We know that ENSO phases are not the only factor in whether floods will occur, nor are they the silver bullet predictor. Regardless of the climate pattern, it is important to remain ever vigilant. Floods can and will occur irrespective of the long-range forecast. Changes in forecasts should not lead to complacency and short-term memory loss about the devastating impacts of flooding.

To demonstrate this point, let’s look at a section of gauges across Queensland and New South Wales to understand the data on the number of flood events, that exceeded moderate levels, in the context of the ENSO climatic phase that those events fell within (image 2).

Image 2: Comparison of gauges across Queensland and New South Wales

Some of the largest events on record and clusters of events fell during La Niña phases however there were still a significant number of events which occurred outside of La Niña phases.

All flood events have the ability to disrupt critical infrastructure, damage properties and cause distress to communities. All floods demand that emergency managers are prepared and have the plans and tools to respond and recover. It is equally important that this planning, preparation and operational readiness is consistent, irrespective of assessments of weather patterns. Understanding the ENSO cycles can be useful but the evidence says floods can occur at any time.

When taking a closer look at a selection of gauges, the number of events and magnitudes differ, however there is a consistent theme - irrespective of the ENSO phase, floods still occur.

Looking at examples such as Ipswich, Queensland (image 3), notable floods in 2009, 2013, and 2017 all occurred during neutral or climate phases that were shifting towards El Niño.

Image 3: One Mile Bridge Gauge, Ipswich, QLD

The same is true for Warwickand the other 35 gauges we selected at random across Queensland and New South Wales (image 4).

Image 4: Condamine River Gauge, Warwick, QLD

What does this mean? Simply, the need to be prepared, act and respond doesn’t change with the climate phase we are in.

It is interesting that when we, as a community, perceive our flood risk to be lower, we often don’t put an emphasis on implementing or further developing our operational tools.

The frequency of flood events can significantly contribute to the average annual damage experienced for assets or the community. Being able to make tangible reductions in damages for all events, big and small, can significantly improve overall resilience.

Furthermore, less intense wet seasons without back-to-back catastrophic flooding, like we saw in 2022, also provides a beneficial environment to make system improvements, test new approaches, and develop updated processes. This is the optimal environment to train, conduct exercises and have open dialogue regarding lessons learnt and what is and isn’t working. 

So, while Australia looks to possibly transition into El Niño, we encourage you to take advantage of this time to evaluate your flood preparedness, response and recovery processes and capabilities.

Real-time situational awareness 24/7/365, irrespective of the climate outlook, is key to being prepared for whatever the weather throws at us.

If a common operating picture, real-time situation awareness or predictive flood intelligence is something you’re lacking, please contact us to learn more about how FloodMapp can assist via sales@floodmapp.com