River Estuary of Death – Fish Kill on the Richmond River
At the NSW Coastal Conference in November 2025, held at Ballina on the Richmond River, much was heard of the impact of recent flood events. In opening the conference before the 260 participants, the Mayor of Ballina Shire informed us of community pain with recent “blackwaters events”. What followed was a reminder by many speakers of legacies of past land use decisions and challenges for future management of waterways bordering coastal flood plains.
The conference was preceded by an excellent workshop arranged by officers from the NSW Department of Climate Change, Energy, Environment and Water. This workshop examined issues related to both river flooding and coastal inundation hazards. These two hazards create significant and perhaps coincident risk to communities and environmental values in NSW coastal floodplains with future impacts being exacerbated by climate change forces. Many options confronting land use planners and river managers were explored including the need to better communicate and align planning considerations for both sets of hazards as they impact on property, infrastructure and water quality.
We were all given a stark reminder of the devastation wrought by floods on the Richmond estuary and flood plain in a magnificent opening keynote address by Chrisy Clay from Rous County Council. The title of her talk gave us a feel for what was to come: “26 years on the Richmond River Floodplain—the grief, hope and the urgency of now”. She has witnessed devastation over this period caused by impacts of blackwater and acid flows off flood plains during and following flood events. Such events have been variously documented by others over the years especially when they have led to massive fish kills. In March this year after the passage of ex-Tropical Cyclone Alfred there was in Chrisy’s words “a smell of death—a sign of things to come”.
What is going on? So much of these estuarine floodplains consist of backswamps. They formed natural wetlands at low elevations with respect to the tidal range. However, these swamps proved attractive for agriculture such as cane farming but they had to be drained. The northern rivers of NSW have a long history of drainage with installation of flood gates to manage ingress of tidal waters. Problems arise when parts of these lands get flooded. The death of plants in farmed areas leads to deoxygenation of waters that flow back into rivers like the Richmond. These drained lands do not have the capacity to absorb the resultant blackwaters. What resulted in March were masses of fish gasping for air and washing up dead along the riverbanks.
Not all of these backswamps are contributing blackwaters to the rivers. Chrisy gave us an estimate on the Richmond of 10.5% farmed land adding 55% of the blackwater. But the land is privately owned and despite many efforts to encourage different management practices she feels things are not getting better. The owners derive income off this land and there are limits to regulations and financial support to create change in practices. At the moment change is seen as voluntary. There are also problems associated with maintaining drainage efficiency (noting that with sea-level rise low tides are getting higher effectively closing the “drainage window”). She expressed frustration at not being able to work at a scale with funds that could potentially transition agricultural use back to wetland to build better environmental resilience and community trust.
The horrendous flood event of 2022 on the Richmond was said to have led to a fear of rain. Cyclone Alfred in 2025 with its further flooding and fish kill made communities more aware than ever of the need to understand impacts. At the conference dinner I was delighted to present the “Community Involvement Award” to a group called “Ozfish Unlimited” for their leadership following the March 2025 event. They had responded immediately by mobilizing volunteers to conduct rapid water quality monitoring and sharing findings with the public in Ballina. They were instrumental in dispelling misinformation and clarifying the causes and consequences of the fish kill. Along the way this group helped bridge the gap between groups with divergent interests such as fishers and environmentalists. And quite significantly, they are now advocating for the long-term restoration of floodplain swamps such as the Tuckean on the Richmond adding to Chrisy’s plea of the need to build resilience against future blackwater events. Work of Ozfish reinforces that of another conference award winner, Kristin Den Exter. She received the “Local Hero Award” for her contributions over several decades as a “Riverkeeper” in restoring riparian vegetation along the Richmond.
There were other valuable conference presentations that developed the theme of improving the ecological function of lands and waters of the Richmond estuary. NSW Government staff, Southern Cross University staff and postgraduate students, and many others, articulated commitments to investigating causes of degradation and pathways to achieving improved environmental and economic conditions. Paraphrasing the words of one presenter: we must strive to overcome “on-going community trauma” with the development of a “smart catchment approach” using the various tools at our disposal.
Recurrent blackwater and acid drain events must be managed at a landscape scale. No single agency is in a position to take responsibility for environmental decline on these flood plains and waterways. Steps are being taken to develop a collaborative governance model that can work in partnership with land holders. Furthermore, work to streamline complex planning approvals is underway to help facilitate the reconnection of tidal flows to backswamps. This is a pathway for restoration of native wetland vegetation and storing of soil carbon, a potential income stream for land owners on what are now marginal farms. Challenges remain especially as the resources required are seen by many as urgent; other flood plains along this coast face similar forces that cause environmental and community harm. This NSW Coastal Conference drove home that sense of urgency and what is needed to achieve improved outcomes.
Bruce Thom
Words by Prof Bruce Thom. Please respect the author’s thoughts and reference appropriately: (c) ACS, 2025. For correspondence about this blog post please email admin@australiancoastalsociety.org.au
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