Hawkesbury-Nepean Valley Flood Risk Management Strategy

A long-term plan to reduce flood risk in the most flood exposed region in New South Wales, the Hawkesbury-Nepean Valley.  

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The Hawkesbury-Nepean Valley (the valley) covers around 500sqm from Bents Basin, near Wallacia, to the Brooklyn Bridge. The valley has the highest flood exposure in NSW because of its unique landscape and large existing population. Floods in the valley can be very deep and extensive, and can have a significant impact on people’s lives, livelihoods and homes.

In 2017 the Resilient Valley, Resilient Communities – Hawkesbury-Nepean Valley Flood Risk Management Strategy (Flood Strategy) was released.

The Flood Strategy is the result of years of investigation into the best ways to reduce the potential economic and social impacts of flooding in the valley. It uses a regional approach as floods from the river system cover a wide area, with impacts felt in 10 local council areas.

Why Hawkesbury-Nepean floods are so dangerous

Key publications

For more information, read publications and frequently asked questions. 

Flood Strategy

There is no simple solution to managing or reducing the valley’s high flood risk. The NSW Government is delivering the Flood Strategy program, together with local councils, businesses and the community.

The program is aligned with the State Emergency Management Plan and the National Strategy for Disaster Resilience. These strategies are the state and national standard for managing the risks of natural disasters. Emergency management in Australia is built on the emergency management cycle which has four elements: prevention, preparation, response and recovery (PPRR).

 

Flood Strategy outcomes

Activities

1. Regional, coordinated flood risk management

Lead: NSW Reconstruction Authority

 Coordination and oversight of the Flood Strategy program, and coordination of flood risk management responsibilities at a regional level. NSW Reconstruction Authority has a dedicated directorate that includes flood risk and evacuation specialists, GIS mapping analysts, and community engagement and resilience specialists. 

2. Infrastructure measures to reduce flood risk

Lead: WaterNSW

 A range of infrastructure measures have been investigated to reduce flood risk. The Warragamba Dam raising proposal was investigated and is not proceeding. Please visit WaterNSW or the Department of Planning and Environment to find out more.

3. Strategic and integrated land use and road planning

Lead: NSW Department of Planning and Environment, Transport for NSW

 A Regional Land Use Planning Framework is being developed to establish a new land use and settlement strategy for the valley. This will help to address the significant flood risk in the valley, in alignment with approaches being developed for evacuation road planning. Read some frequently asked questions about land use planning.

4. Contemporary flood risk information

Lead: NSW Reconstruction Authority

A new Hawkesbury Nepean Valley Regional Flood Study was completed in 2019 using the latest data and science available and a sound scientific approach. Read the Flood Study Overview.

Further work is underway to increase understanding of flood behaviour using latest information including recent floods from 2020, 2021 and 2022. Public consultation and release of a new Hawkesbury-Nepean River Flood Study is planned for late 2023.

5. An aware, prepared and responsive community

Lead: NSW Reconstruction Authority, NSW State Emergency Service and Transport for NSW

An extensive Community Resilience Program aims to increase flood awareness and preparedness. This includes programs for:

  • young people in schools with both primary and secondary school teaching and learning resources available. View school resources.
  • broad community awareness campaigns and resources, including a new flood mapping tool, videos and other resources. View flood preparation resources.
  • broad community preparedness campaigns, including content for the CALD community and animal owners. Visit NSW SES Get Ready Animals and receive in language material.
  • a communities of concern program with targeted partnerships addressing the most vulnerable, including those with animals.
  • new flood evacuation signage across the floodplain.

Read an overview of the Community Resilience Program or watch the Community Resilience Program showcase video.

6. Improved weather and flood predictions

Lead: Bureau of Meteorology

 The Hawkesbury-Nepean Advanced Flood Forecasting pilot project has developed new rainfall and flood forecasting tools which will provide better information about the timing, behaviour and heights of floods. This will help emergency services to understand and respond to floods which, in turn, helps the community to respond to flood alerts and warnings.

7. Best practice emergency response and recovery

Lead: NSW State Emergency Service and NSW Reconstruction Authority

Emergency response and recovery agencies work together to maintain, test and enhance capability in the floodplain. In 2019, a series of exercises was delivered across the emergency management sector to test and improve coordination of response to and recovery from a major flood in the valley.

The Hawkesbury-Nepean Flood Plan continues to be updated to take account of contemporary flood risk information including recent flood events in 2020 and 2021.

8. Adequate local roads for evacuation

Lead: Transport for NSW

 The Flood Strategy identified the need to deliver a resilience roads package to maintain and upgrade local evacuation roads to ensure access to major regional evacuation routes. Local flood modelling and technical assessments were undertaken to identify and prioritise appropriate road upgrades for the package.  A strategic-level business case has been developed for NSW Government consideration.

9. Ongoing monitoring and evaluation, reporting and improvement of the Flood Strategy

Lead: NSW Reconstruction Authority

 A framework has been developed and is being implemented to monitor, evaluate, review and improve the Flood Strategy program over time. Key considerations include potential changes to community profiles and preparedness, urban development, road evacuation capacity, climate change and experience from flood events. View the interim evaluation report.

Read the Flood Strategy and frequently asked questions (FAQs) about the Flood Strategy.

In July 2023 the Hawkesbury-Nepean Flood Risk Management Directorate transitioned from INSW to the NSW Reconstruction Authority (NSWRA). The NSWRA is committed to improving how NSW plans for disasters and making sure communities across the state recover from them faster. It was established under the NSW Reconstruction Authority Act 2022 and its key functions include:

  • mitigation and adaptation including public infrastructure, homes and land use planning
  • local preparedness including education and community information
  • community-centred recovery
  • long-term rebuilding and reconstruction

Development of a Disaster Adaptation Plan (DAP) for the Hawkesbury-Nepean Valley, which builds upon the 2017 Flood Strategy, is underway.