Northern Rivers Resilience 
Initiative – progress update

The National Emergency Management Agency (NEMA) engaged CSIRO 
to undertake the Northern Rivers Resilience Initiative (NRRI). 

The NRRI aims to help the Australian Government understand 
the drivers behind the unprecedented flood events in 
February–March 2022 in the Northern Rivers region of NSW 
and develop community-supported solutions for flood 
mitigation and resilience investment. This initiative enables 
CSIRO to assess existing project proposals and identify further 
long‑term options for reducing flood risk in the Northern 
Rivers region.

The NRRI consists of two phases:

1. Rapid review and assessment (Phase 1 – July to November 
2022, completed) – This phase identified and prioritised 
existing flood resilience/mitigation project proposals. 
It characterised the catchment and climate conditions 
which led to the 2022 floods and analysed the most effective 
intervention options for allocation of the Australian 
Government’s $150 million of funding. 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 completed the rapid review and 
assessment phase and submitted two related reports to 
NEMA on 30 November 2022. These reports and a full 
list of project recommendations were then considered 
by the Australian government. On 23 February 2023, 
the first 16 projects totalling $50 million were announced. 
On 28 July 2023, the second 20 projects totalling more 
than $100 million were announced. CSIRO and NEMA have 
now completed phase one of the NRRI with $150 million 
Commonwealth funding provided for flood mitigation and 
resilience projects in the Northern Rivers region to support 
the NSW Government to fast-track resilience efforts.

2. Detailed modelling (Phase 2 – Ongoing to June 2025) – 
This longer-term program of work is collecting and 
generating high resolution and high accuracy Light 
Detection and Ranging – LiDAR (a digital representation 
of the bare-earth’s topographic surface). The data provides 
spatial analysis and hydrological/hydrodynamic modelling 
of water movement for the entire Northern Rivers 
region. The project is also collecting river bathymetry 
(continuous river cross sections) using boats for the 
Richmond and Tweed rivers and their main tributaries. 
This high-quality data will be used to underpin a detailed 
hydrodynamic model for the Richmond River catchment. 
The model will be used for examining and evaluating 
possible future events and scenarios and predict their 
outcomes while drawing on local knowledge and expertise 
on the catchment and flooding.

Outcome – CSIRO will generate high quality digital elevation 
data sets for the Northern Rivers region based on the 
collected LiDAR and bathymetry data sets. This, along with 
other data, will be used to develop a detailed hydrodynamic 
model for the entire Richmond River catchment. Researchers 
will then use this model to undertake scenario analysis to 
evaluate flood mitigation actions, in the context of climate. 
The report for this work and fully calibrated model is due in 
June 2025 (noting there were some delays in data collection 
due to unfavourable weather conditions). Scenario testing 
will take place in 2025–26. The LiDAR and bathymetry 
datasets will be made publicly available and can be used 
by regional councils, Australian and state government 
agencies, researchers and community members across 
the region.

This map identifies the flood-effected Local Government Areas in the 
Northern Rivers region of NSW where the project is being carried out.

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Australia’s National 
Science Agency



Frequently asked questions 

What is the model that CSIRO is building for the 
Richmond River catchment? 

The model is a hydrodynamic model (HD), which is a 
representation of water flows across the Richmond River 
catchment (more than 7000km2). The model aims to represent 
the key hydrological (water flow) processes related to flooding 
across the catchment and will be able to reproduce the past 
flooding history in the catchment. Once completed, the model 
can be used to investigate the changes in flooding associated 
with changed climate, as well as structural and non-structural 
infrastructure options designed to mitigate flooding. 

The model design is based on detailed spatial representation 
of the catchment’s biophysical characteristics such as soils 
(infiltration rates, soil storage capacity, etc) and landscapes 
(roughness, flow paths, flow direction, structures, vegetation, 
etc.). The landscape surface of the catchment is represented 
in the model with a continuous flexible mesh (millions of 
triangular facets) with very fine representation in the areas 
important for flood generation, movement, flow barriers 
as well as residential, commercial and industrial areas, and 
coarser in areas which are not impacted by floods. 

The hydrodynamic model will be validated (checked for 
accuracy) against: 

• flood extents mapped through remote sensing 
(using satellite products from Landsat, Sentinel, etc.)
• measurements at internal flow gauges
• on-ground observations. 


This will provide confidence in the model to be used for any 
future climate change or flood mitigation scenario analysis. 

Given the size of the Richmond River catchment, model 
complexity and simulation time steps (at times during wet 
conditions the model runs every few seconds), a complete 
model simulation of the catchment will take up to 3 months. 
On CSIRO high performance computing, this can be reduced 
to a run-time of close to one month. 

The Richmond River catchment hydrodynamic model is 
specifically developed to represent water flows across the 
Richmond River catchment for the purpose of understanding 
the flooding in the catchment and for evaluating flood 
mitigation scenarios. It should only be used for the intended 
purpose and not for other purposes where we might need 
a different type of model.

Has Phase 2 of the NRRI been delayed and if so, why?

The Light Detection and Ranging (LiDAR) digital elevation data 
and the mapping of river cross sections (bathymetry) data 
collection commenced in July 2022 and is ongoing. 

The Bathymetry data will be available for use in early 2024. 

There were significant delays to the LiDAR collection due to 
unfavourable weather conditions across the region over the 
last year. The LiDAR collection for the Richmond catchment is 
close to completion and we anticipate that it will be complete 
by end of 2023. A detailed quality assessment will then be 
undertaken and we are expecting the final LiDAR data to be 
publicly available by June 2024. This high resolution and high 
accuracy LiDAR data set is a critical input for the Richmond 
River catchment hydrodynamic model. 

The detailed hydrodynamic model for the Richmond River 
catchment is currently being built. This will use the LiDAR and 
bathymetry data sets, and the model will be able to evaluate 
future changes in flooding due to climate and mitigation 
scenarios at the catchment scale. Although there are some 
existing flood models, these represent smaller areas or only 
sections within the catchment, and a catchment scale model 
has never been built before for the Richmond River catchment. 
Building this model is both a complex and time-consuming 
process. The model needs to be done at the highest precision 
to get reliable estimates to underpin any future flood 
mitigation options.

Researchers use sonar equipment from boats like this, including remote 
controlled boats (inset), to collect accurate information about cross 
sections of the river network (known as river bathymetry) to inform their 
hydrodynamic modelling. This image, from geospatial experts AAM, 
pictures AAM personnel using sonar equipment on the water.

Regular updates about the progress of NRRI are available on the CSIRO and NEMA websites 
(above). Regular updates are also provided to the project Governance and Advisory panels, 
the Northern Rivers Joint Organisation (NRJO), local councils, stakeholders and communities.

As Australia’s national science agency, CSIRO is solving the 
greatest challenges through innovative science and technology.

CSIRO. Creating a better future for everyone.

For further information

nrri@csiro.au | contact@nema.gov.au

csiro.au/nrri | nema.gov.au/programs/emergency-response-fund/northern-rivers-resilience-initiative

This project is funded by the National 
Emergency Management Agency