Submissions closed

Submissions have concluded for the Somersby & Kariong Catchment Overland Flood Study, undertaken by specialist flood consultants, Kellogg Brown & Root. The community questionnaire aimed to help us get a better understanding on the nature of flooding in the area to help inform future planning and management activities. The study area consists of the Kariong residential area, the Somersby industrial area, and the rural residential area immediately to its north (as mapped below). The NSW Government's Department of Planning and Environment are providing financial and technical assistance to help facilitate this project.

The aim of this study was to:

  • Develop a baseline understanding of the nature of flooding using the most current information and technologies
  • Help better understand local flooding problems
  • Build community resilience by informing better planning of development, emergency management and community awareness
  • Develop information to assist in future floodplain management activities to reduce flood impacts on the community and risk to life
Map of study area

Submissions have closed

Community involvement is essential to the success of the floodplain risk management process as it enables the community to:

  • Contribute local knowledge of flood behaviour
  • Directly influence strategic planning for development in flood prone areas

As a result, we received your feedback for this Flood Study between Monday 21 August and Friday 22 September 2023 via online submission form and email.

During the development of the Floodplain Risk Management Plan, residents will have further opportunities to help decide which flood mitigation measures they think are best for their local community. All survey information will remain confidential and will only be used for floodplain risk management purposes.


When providing feedback to Council your attention is drawn to the provisions of the Government Information (Public Access) Act 2009 which allows for possible access to certain public and personal documentation. View our privacy statement.

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Consultants review submissions and prepare flood study

Who's listening

Who's listening
Daniel O'Brien, Project Manager


How is this study funded?

Council has engaged specialist flood consultants Kellogg Brown & Root Pty Ltd to prepare this study, which is jointly funded by the NSW Government ‘s floodplain management program, and Council.

What parts of Somersby and Kariong are included in the study area?

The study area consists of the Kariong residential area, the Somersby industrial area, and the rural residential area immediately to its north. The figure below shows the precise study area boundary.

Map of study area
Why Somersby and Kariong?

While Kariong and Somersby are very elevated compared to the Mooney Mooney Creek and the Hawkesbury River downstream, this is not to say that these areas aren’t susceptible to short intense bursts of rainfall that produce flash flooding. Council has very limited flood information in this area, and thus new flood modelling using the latest industry practices will provide great insight into the nature of flooding, whilst also providing benefit to the community in terms of land use planning and emergency response.

As a consequence of new flood mapping, this does mean that some properties may become identified as flood control lots on their Section 10.7 Planning Certificate, however under the NSW Government’s Flood Prone Land Policy, Council has a duty of care to manage land that is subject to flooding within its Local Government Area. Thus, Council is responsible for formulating and implementing Flood Studies and Floodplain Risk Management Plans in accordance with the policy.

There are immense benefits to having a better understanding of flood risk in any given area and Council are always working to make information about the potential impact of floods more easily available to owners, buyers, lenders and insurers. When insurers are uncertain about flood risk, they may actually charge more for flood cover to cover unknown risks.  If councils can provide insurers with clear, up to date information (as per the intentions of this study), they can be more accurate in their risk assessment, which may ultimately lead to a potential reduction in premiums.

How can I have my say?

Submissions closed on 22 September 2023.

Where can I find out more?

You can find out more about Floodplain Management here, or email if you have any questions.

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