There appears to be a fight looming between the Northern Rivers Joint Organisation and the NSW Reconstruction Authority for which agency will lead the Northern Rivers Master Plan and Vision piece.

Jai Vaze, Senior Principal Research Scientist with the CSIRO, told members of the Lismore Floodplain Management Committee recently that his flood mitigation modelling would benefit from a vision document. If this was not forthcoming, Jai and his team would be formulating the possible mitigation scenarios themselves.

"We won't be running too many (scenarios) when the run times are like two months," Jai said, "We will be running three to five mitigation scenarios together, it will not be a single one."

The Northern Rivers Joint Organisation (a monthly meeting of mayors and general managers from each council area) passed a resolution for the funding to come from the NSW Reconstruction Authority (NSWRA) and that the CSIRO be engaged as the agency to develop the Regional Vision, Masterplan, Feasibility Study, Disaster Adaptation Plan, and associated documents and plans. The vote was unanimous.

Lismore Mayor Steve Krieg told the Lismore App, that the Regional Vision piece is critical for Lismore's vision called 'Reimagine Lismore' by Lismore City Council.

"It means nothing unless we have a Reimagine Northern Rivers. It's critical that all of these cogs in the wheel intertwine to come out with the best outcome not only for Lismore, moving forward but also the other council areas in the Northern Rivers."

Mayor Krieg said he put the motion forward based on a verbal assurance that funding had been secured to get the CSIRO to be the agency that provides the Regional Master Planning and Vision piece.

"It makes a lot of sense to have that organisation. To have one independent body, looking after flood mitigation for the region, and then looking after master planning and a vision for the region makes a lot of sense."

When asked about funding for the Regional Master Plan and Vision, Member for Lismore Janelle Saffin said, "I am told, funding can be found through NEMA and the RA."

The Lismore App asked the NSWRA, if funding has been secured and if the CSIRO has been approached to be involved in the project.

A spokesperson for the NSWRA said, "The NSW Reconstruction Authority will hold a facilitated workshop in the coming months with the Northern Rivers Joint Organisation and key stakeholders to develop the scope of the NRJO’s regional vision."

"Once the scope is developed, the RA will engage a provider to deliver the works."

Jai Vaze said he had not been approached by anyone from the NSWRA to ask about the CSIRO's availability.

As part of Jai's update on building the Northern Rivers first detailed flood mitigation model, he said one component to building the CSIRO model is the collection of high-quality data sets which has now been completed, this includes the LIDAR (Light, Detecting and Ranging), bathymetry data (measurement of water depth) and the reevaluation model for 30,000 square kilometres of the Northern Rivers.

"Currently CSIRO is undertaking the quality assurance to make sure everything is ok," Jai told the meeting, "It's a massive data set, it's 16 points per square metre. That's the most accurate you will go."

This data will be made available to the public on 30 June 2024, so in four months, through the Geoscience Australia website. Geoscience Australia is the federal agency that holds all the spatial datasets for Australia due to their size. Jai said for this project the data sets are 'terabytes and terabytes'.

The second part of the research project is the hydrodynamic model. This is where the entire Richmond River catchment area is broken down into mesh sizes where the high-flow parts use a really fine mesh and the low-flow parts a coarse mesh.

The CSIRO has supercomputers that take about two months to run one simulation.

Jai Vaze did point out the "big difference" between consultants and the CSIRO. The CSIRO runs simulations on the actual event using a continuous model. So, for the February 2022 flood, the CSIRO model will start somewhere in October or November 2021.

The final report is due for release in June 2025.

After the report is released, each local council can then hire consultants to use the CSIRO data to run specific Lismore modelling, as Engeny has in the past for Lismore or BMT in Ballina. This will mean the local reports will have a lot more accuracy and detail because of the CSIRO report which means the public will have a great deal more faith in local flood mapping which council uses to determine planning heights in certain areas and which streets are high risk to life for different river heights.

The initial testing and some comparisons will be finished by December 2024 when Jai will come back to the region to talk to people from Lismore, The Channon, Nimbin, Ballina and more plus councils to see if the model is right.

"There will be a few tweaks", following the visit which will determine if June 30 2025 will be the release date of the full Northern Rivers Flood Modelling report.

Once complete, the flood mitigation scenarios can be run to find the most effective combination of scenarios that will reduce the impact of future floods.

As Jai has said previously, this has to be for the entire Richmond River catchment. The consistent message coming from the CSIRO is that the water has to be stopped or slowed before it gets to Lismore, Coraki, Woodburn or Ballina so this means solutions in the upper catchment will be part of the solution.