In a lot of ways, the CSIRO is the most important organisation in Lismore's flood recovery.

Forget the Federal and State Governments and forget the NSW Reconstruction Authority. Sure, they have a vital role to play in getting the Northern Rivers back to a thriving region of NSW that is highly desirable for families to move to, but they cannot take a potential metre off a major flood. The CSIRO has that potential and is another step closer to unlocking those theoretical answers.

It does feel like another lifetime since the CSIRO signed a contract to participate in the $11.2 million Northern Rivers Resilience Initiative (NRRI), which was led by the National Recovery and Resilience Agency. That was two years ago.

The NRRI was to perform a study that had not been seen before in the Northern Rivers. The result would be data down to every square metre across the 7,000 square kilometres of the Richmond River catchment area.

Lead CSIRO scientist for the NRRI project Jai Vaze today confirmed that the data will be ready on time, by June 30, as promised.

"It is finished and will be released around June 30 or July 1," Jai said." It will then be available on the Geoscience Australia website through Elvis (Elevation Information System) to all stakeholders and the public."

This data includes all of the LiDAR (Light Detection and Ranging) data collected (using planes) and river bathymetry (using boats) for the Richmond and Tweed rivers. This was used to underpin a detailed hydrodynamic model for the Richmond River catchment.

"As we are putting our stamp on this work, it has had to pass all the quality checks. This is a really high-quality work that local councils like Tweed, Lismore, Ballina and Rous can use for local area flood modelling."

This means Lismore City Council can ask their consultant to run flood modelling for the Lismore CBD. Previous modelling did not use data from the 2022 big flood. In fact, Jai said, some data used by some councils dated back to 2008.

Unfortunately, at this stage, this will only focus on the CBD and not include water flow from hills such as The Channon or Nimbin. Jai said the landscape changes a great deal following large floods like 2017 and 2022.

Ballina, Tweed and Richmond councils will run their own CBD modelling while being able to look at land stability and landslip potential. Rous County Council can use the information for water use planning, and Transport for NSW can use it for road/highway planning and design.

This data set does not include any flood mitigation possibilities. That part of the project begins now.

"We will be building the flood model over the next twelve months," Jai said, "That should be ready by 30 June 2025, and then we can run various scenarios post-June 2025. This is a huge project; this model will be the first time that a Richmond River model is being built. The Northern Rivers needs a full catchment model to see what changes will happen. No one has attempted this before."

As for what scenarios will be tested by the CSIRO, that will be determined by the various stakeholders, like the seven local councils, the Federal and State Governments, NSWRA and Rous County Council.

Only when the scenarios are run can Jai and his team say what impact a particular flood mitigation scenario will have on flood levels.

On June 30 2024, we can say progress has been made. However, the flood mitigation question is still 18 months to two years away.