The Australian Government is providing $150 million in 2022–23 for priority flood resilience projects in the Northern Rivers region of New South Wales.
The Northern Rivers Resilience Initiative will provide science to inform the investment, through a process to understand the drivers behind the unprecedented flood event in February-March 2022 and develop community-supported solutions for resilience investment.
The National Emergency Management Agency (NEMA) has engaged Australia’s national science agency CSIRO to support the Northern Rivers Resilience Initiative, which will consider climate, catchment and hydrological systems, and the broader influences of land-use practice and infrastructure.
This $11.2 million Initiative will enable us to assess existing project proposals and identify further long-term options for reducing flood risk in the Northern Rivers region. A core part of the project is to undertake engagement with key stakeholders to seek their views regarding priorities for investment.
The project consists of two key parts:
- Rapid review and assessment phase – the first six months (July to November 2022). This phase identified and prioritised existing project proposals. It analysed the most effective intervention options for allocation of the Federal Government’s $150 million funding and characterised the catchment and climate conditions which led to the 2022 floods. This also involved considering the historical perspective of flooding in the NSW Northern Rivers region. Residents and councils, in each of the seven flood-affected Local Government Areas in the region (Ballina, Byron, Clarence Valley, Kyogle, Lismore, Richmond Valley and Tweed) were consulted to help identify and prioritise the most effective intervention options.
Outcome – CSIRO has now completed the rapid review and assessment phase and submitted two related reports to NEMA on 30 November 2022. These reports are currently being considered by NEMA and will inform decisions on future investment in this region.
- Detailed modelling – Over a two-year period (July 2022 to May 2024). This two-year program of work will collate and generate Light Detection and Ranging (LiDAR) data to provide spatial analysis and hydrological/ hydrodynamic modelling of water movement for the Northern Rivers region. It will also involve examining and evaluating possible future flood events or scenarios, drawing on local knowledge and expertise on the catchment and flooding.
Outcome –This phase will generate high quality digital elevation datasets for the Northern Rivers region and collect bathymetry for the Richmond and Tweed rivers. These datasets, along with other data, will be used to develop detailed hydrological and hydrodynamic models for the entire Richmond River Catchment. Researchers then use these models to undertake scenario analysis to recommend long term flood mitigation actions. The final report for this work is due in May 2024.
Community and stakeholder engagement
From July to October 2022, the CSIRO team engaged with stakeholders in the flood affected areas. To view the time-line of activity read our factsheet Northern Rivers Resilience Initiative PDF (351 KB)
CSIRO worked closely with Alluvium Consulting, an environmental consultancy, and their local staff, along with NEMA Recovery Support Officers based in the region for the rapid review and assessment part of this project. Meetings and workshops with local councils and community groups discussed existing information, identified relevant materials on flood risk, and canvassed community views to inform the research.
To contact the CSIRO project team email firstname.lastname@example.org
Frequently asked questions
Can you explain the two different methods researchers are using to collect data?
LiDAR flights – An aeroplane with LiDAR sensors attached, will be flying over the region. These sensors are a remote sensing method used to collect accurate digital elevation models for the region for hydrodynamic modelling. There will also be ground crew doing surveys to ground-truth information collected by the LiDAR equipment attached to the plane.
River bathymetry – Locals may also see boats in the rivers with sonar equipment collecting accurate information on the cross sections of the river network (river bathymetry) to inform the hydrodynamic model. This may include small remote-controlled boats for smaller and steeper streams.
This data will complement existing data sets available to local and state governments, to inform flood mitigation planning and activity in the region.
Will the LiDAR data sets for the modelling be made publicly available?
Yes, we will make the data sets available by mid 2023 once the collection and processing is done. Noting the final report is not due until May 2024
Please provide definitions of catchment and basin for the purposes of this project?
A basin or river basin or drainage basin is an area which all drains out through a single point (any runoff generated in this area drains out through the basin outlet). Normally there are multiple catchments within a river basin draining individual smaller sub-areas contributing to the basin outflow. Sometimes, in hydrology literature, catchment is used as a surrogate for basin. A Local Government Area (LGA) can cross basin boundaries and may include only part of one basin or different parts of multiple basins.
Don't all of the catchments merge together, and therefore the modelling of one catchment needs to take into account the other catchments?
No, there are several separately draining catchments with the Northern Rivers region. These river basins drain through different points (and independent of each other). As such, each catchment needs to be modelled separately for hydraulic modelling.
Will this modelling take into account the impact of climate change on future flood levels?
Yes, once the model is developed, it can be used to test any scenario including impact of climate change on future flooding. The plan is to develop a detailed hydrodynamic model for the whole Richmond catchment to reproduce past flooding history and overland flood inundation. The model will be further fine-tuned in consultation with local community (local on-ground knowledge) to make sure it can reproduce the key aspects of overland flooding at fine scales. After this, adaptation/mitigation scenarios will be developed which may be a combination of infrastructure and non-infrastructure options for any historical or future climate.