CSIRO NRRI Report – BES’ Ballina Community Session Summary
Member Briefing prepared for the BES General Meeting – 8 August 2026
NEMA and CSIRO held public information sessions across the catchment (Kyogle, Casino, Ballina and Coraki) to present the findings of the June 2026 NRRI final report and receive community comment on the flood mitigation options it outlines. This note summarises the Ballina session for BES members ahead of our next general meeting.
Approximately 75 community members attended the Ballina session, of whom 6 were BES members.
Observations from the Session
Session format.
The session opened with a Q&A before CSIRO had presented the scope of what it was originally commissioned to model. A number of attendees asked questions without that context, which led to some frustration in the room.
Scope versus community expectations.
The brief given to the CSIRO researchers was focused on hydrological flood modelling and mitigation options – reducing and managing flood impact once a flood is under way – rather than a broader strategy addressing the root causes, frequency or long-term disruption of flooding. As the panel consisted of hydrological researchers, responses to broader questions were necessarily narrow, reflecting the scope of the brief rather than any shortcoming in the panel itself.
Value of the model.
The region now has a detailed, validated hydrological model capable of replicating past Richmond River flooding events. This model could, in principle, be extended to test future scenarios by adjusting input variables (for example rising sea levels, climate-change-adjusted rainfall, or nature-based flow reduction estimates). Several attendees noted the value of the hydrological model in illustrating the scale of the flooding challenge, alongside scepticism about the proposed structural measures.
Community questions and concerns.
Attendees asked about expected changes in water flow and velocity from canal and creek works. The Bundle 2 water detention arrangements and release strategy required further explanation, as did the proposed Boundary Creek diversion and its potential effect on estuarine sedimentation from reduced flood flow and velocity. Several attendees viewed the study as an initial base for further work on flood mitigation strategy, rather than a finished plan.
Community sentiment.
Concerns about the proposed options outweighed expressions of support in the room. A specific figure was cited for the height of some proposed detention basins. It is understood at least two new, opposing community Facebook groups have since formed locally in response to the proposals [names withheld here pending Committee decision on whether to name other groups in member communications].
Key takeaway.
The mitigation scenarios presented appear, at this stage, to be a mismatch with the community's broader expectations for a flood resilience strategy. Presenting high-impact structural options such as large detention basins without a clearly communicated, integrated framework risks fuelling local division rather than building consensus. There is now a clear task ahead in community engagement, so that further discussion can proceed on the basis of shared, accurate information.
BES Discussion Points
Nature-based solutions.
As BES advocates for nature-based approaches to flood mitigation, it will be important for BES to understand and communicate what scale of nature-based intervention would be needed to achieve flow reductions comparable to the proposed detention basins – or, at minimum, what scale of nature-based work could allow individual detention basins to be reduced in size and impact. There was general agreement among attendees that nature-based solutions should have been included within the scope of this study; we understand a Richmond Landcare Inc research project is examining nature-based solutions for flood mitigation separately. BES's position is that both approaches should be assessed for flood mitigation impact using the same hydrodynamic model, so that they can be compared on a like-for-like basis.
River health.
Pending further reports, it should be noted that the CSIRO modelling to date has considered water flow and flood levels, but not the broader ecological health of the Richmond River. One attendee at the session commented: “The Richmond River is being treated with contempt. It is a life form, not a drain.” (BES/Landcare/OzFish representative)
Related research.
OzFish's parallel research into river health as a factor in flood mitigation is a welcome complementary body of work. The NSW Government's Coastal Dredging Strategy 2019-24 should also be incorporated into any future comprehensive assessment.
A report “Sediment Pollution Sources to the Richmond River” prepared by Griffith University in November 2025 for Rous County Council highlights the scale and intensity of erosion, particularly in the Mid and Upper Richmond catchment, and is directly relevant to this discussion.
BES's view is that flood mitigation and river health should not be treated as competing, either/or questions. The best outcome will draw on all of the available evidence to reduce flooding impact while minimising harm to river health.
Presenting the CSIRO report in isolation from these other relevant research studies was, in our view, a missed opportunity to give the community a fuller picture.
NRRI's Stated Next Steps
NRRI's closing comment at the session was that the CSIRO report's recommendations would not be implemented without further feasibility and constraint studies, cost-benefit analysis, viability assessment, and assessment of infrastructure, property and social impacts – and, we would hope, incorporation of the other relevant research noted above.
More resources:
CSIRO information about NEMA and full report: Northern Rivers Resilience Initiative
National Emergency Management Agency: https://www.nema.gov.au/
Nature Conservation Council - NRRI, have your say - https://www.nature.org.au/nrri
