Jai Vaze is not a household name in Lismore and the Northern Rivers, but he is one of the most important people in the region when it comes to future flood mitigation.

Jai is the Senior Principal Research Scientist for the CSIRO and the man leading the flood mitigation research project for the Northern Rivers.

Jai and his team spent the first six months characterising the floods, putting them in perspective and ranking the 330 proposals they collected. This formed the Phase 1 Interim Report that was released on February 23 this year, which funded two tranches of funding, $50 million in February and a further $100 million in Friday's announcement by Federal Minister for Emergency Services Murray Watt.

Mr Vaze said Phase 1 is now finished, and Phase Two, the most critical of the project, is the focus for the next 18 months.

"Phase two has two components. One is collecting high-quality data sets. So, we are collecting digital elevation model for the entire Northern Rivers, that's close to 30,000 square kilometres, seven LGAs."

This phase includes mapping the bathymetry, or continuous cross-section of every metre of the river in the Richmond and Tweed and all its main tributaries.

Mr Vaze said this is slightly delayed because of last year's weather, but it is progressing. Then all of that data, along with Phase 1 data, will be used to build a fully distributed hydrological model for the entire Richmond River catchment. This covers four local government areas.

"We expect to get the calibrated model which can reproduce the past history for the entire region, all the flooding, by December next year," Mr Vaze said.

Mr Vaze explained that the way the CSIRO operates is by producing a model that can reproduce the past, then you can have confidence that the model is doing the right job.

Once that is complete and confidence is high, the CSIRO will look at multiple options and combinations to see what mitigation methods effectively lower flood levels.

"We don't have those options yet, but we'll develop those with the community, local councils and state government," Mr Vaze said, "Another thing that is important is given it's a full Richmond catchment model, we will make sure that by protecting someone upstream, so by protecting Casino we are not making it worse for Coraki or by protecting Lismore we're not wiping out Coraki or Woodburn."

As for the anticipated date of the scenario modelling results?

"It will all be completed by 2025, but the results will hopefully be available by mid-2025."

When asked about the mid-2025 date being two years away, a long time for people to wait, Mr Vaze said, "I will make one comment, and I'm making that as a scientist. I'm a CSIRO person. To get something right, you need to invest time because you try and do a quick fix, and you keep facing the same problem again and again."

"I'm actually quite surprised that the whole catchment doesn't have a model. The federal government this time funded, for the first time, a model for the entire Richmond, which is the most flood-prone area in Australia. At least you will have a model where you can actually see the solution for these models."

"The solution for Lismore is not in Lismore, Ballina is not in Ballina. Most of these solutions are in the catchment scale far upstream of where it's happening. And you need a model to do that. So maybe to get the right solution and get it fixed for once and for all, two years is not great. The region is waiting for 50 years. That's what I have heard from many of you."

Listening to Jai Vaze, you have confidence that the CSIRO will build an accurate flood model, forming the critical part of the flood mitigation scenarios. The questions arise when Mr Vaze made this comment about creating different scenarios for the entire catchment.

"It won't be one scenario that will fix everything. You might be looking at combinations of doing something upstream of Lismore, something up in Casino, something somewhere, and then look at the combinations and the costings because we will provide those options. The state government and the federal government will make the decision on how much investment they are ready to put in."

From the communities perspective, that is when the faith is most likely to wane. We can use the $1.5 billion that was applied for from the NRRC for the Resilient Homes Program and the Resilient Lands Program as an example.

The Northern Rivers has been allocated $700 million and $100 million as part of Tranche 1 funding, so the House Buybacks, House Raisings and House Retrofits need to fit that budget. Tranche 2 funding is part of a program re-set with conversations happening between the state and federal governments.

Will the best flood mitigation scenarios be subject to funding?