The CSIRO has released its final report into flood mitigation for the Northern Rivers, which includes opening Boundary Creek, upgrading the Tuckean Swamp plus multiple water detention basins around the upper catchment to lower flood levels.

However, neither the federal nor state government has committed to the work outlined in the $11.4 million report.

Instead, the Albanese and Minns Labor Governments today announced that another $3 million would be spent “to progress flood resilience planning across the Richmond River catchment”.

This would include a full cost-benefit analysis and scoping engineering work.  NSW Minister for Recovery Janelle Saffin says this next study could take another 18 months to two years.

The CSIRO investigated engineering options to reduce flood peaks and today announced a preferred option – Bundle 2 (pictured above).

Bundle 2 has detention basins across the Richmond River Catchment, plus a Tuckean Swamp bypass and drainage, the Baggotville barrage upgrade, and installing a one-way pressure gate at Boundary Creek that would let flood water out but stop sea water entering.

According to the CSIRO website, “the larger or more comprehensive bundle of measures, known as Bundle 2, delivered the greatest benefits.”

Ballina Mayor Sharon Cadwallader is calling for the next scoping study to be fast-tracked saying Ballina can’t wait years for flood mitigation, but she says Bundle 2 is “definitely the way to go” .

“That’s what I’m hearing from the long-terms who’ve lived here for a very long time, the water used to go out to Boundary Creek and it was stopped,” she said.

Ms Cadwallader is also calling for the CSIRO and Federal Government to lead the scoping study because the community has lost faith in the NSW Reconstruction Authority.

CSIRO concedes it can not “flood proof” Lismore – bundle 2 would not have stopped the 2022 floods inundating Lismore – water breached the levee by 3.5m to 4m. The bundle of works the CSIRO outlined would take the Lismore flood peak down by 2.07m.

CSIRO hydrologist Dr Jai Vaze and his team collected data by plane and boat to build what CSIRO describes as “Australia’s most comprehensive and accurate flood model”.

“The model has surpassed my expectations, I was actually expecting smaller reductions,” said Dr Vaze.

“To be able to show how the water level could be reduced by up to 2.07 metres for such a major flood is substantial and goes a long way towards helping the region as well as governments.”

There has been a mixed reaction to the report from local leaders.

Ms Saffin, who is based near Lismore, says the report “gives us real hope because it shows technically that flood levels can be lowered across all four local government areas in the Richmond River catchment – Kyogle, Lismore, Richmond Valley and Ballina.”

But NSW Greens MP Sue Higginson, who calls the Northern Rivers home, says a series of dams could make flooding worse.

“This report confirms what flood experts and the community have been saying all along, billions of dollars in new dams for the Richmond Rivers will not prevent severe flooding and could make floods far more dangerous and long-lasting,” she said.

Ms Higginson says pouring concrete into the upper catchment will damage the environment and destroy heritage.

Page MP Kevin Hogan has issued a statement saying, “The CSIRO have provided a solution to keep us safe. The State and Federal Labor Governments must act on this … It’s time to get to work implementing these CSIRO solutions so we never have people going through the trauma we suffered four years ago.”

The CSIRO believes lessons learnt through the Northern Rivers study could be applied to other flood-prone areas of Australia.