What is a tributary?

    A tributary is a river or stream flowing into a larger river or lake.

    Why did I receive a letter and information?

    Letters have been sent to residents, property owners and businesses in potentially flood-affected areas close to the minor lake tributaries involved in the project. The information enclosed provides an overview of the flood studies project and asks for your feedback via the survey or online before Friday 17 April.

    Why is Council doing these flood studies?

    We’re doing these flood studies to improve safety for residents. The outcomes and recommendations will improve protection for properties, assist planning for residential growth and development and improve management of our waterways.

    Under NSW planning laws, councils are responsible for managing local flood planning. We’ve engaged WMAwater, a specialist consultancy in flood models and floodplain management, to complete studies on eight minor tributary catchments where a flood study has not previously been undertaken.

    These eight remaining tributary catchments flow into the Lake Macquarie waterway and have a history of flooding or have otherwise been identified on our records as having the potential to flood. We need to be prepared. The flood study will establish scientific hydrologic and hydraulic computer models of the study area, which then are used to establish probability flood levels, extents and velocities within this study area, and map areas affected by flood events in a range of scenarios.

    The flood study will be used to inform a floodplain risk management study and plan later in the flood management process.

    You can help inform the study by sharing flooding history or experiences, photos, videos and location information about your area with Council and the consultant.

    Why is it important for residents and community members to get involved and share flooding experiences in these areas?

    Your experiences, flooding information, photos and videos will help to inform the flood study for your catchment. It is important for us to gather as much information as possible, especially from local residents, property owners and businesses, about the flooding history in areas close to the tributaries.

    The consultants will combine all of the community information with results from flood modelling technology to develop the flood studies.

    Community input provides a significant aspect of real-life information and impacts contributing to the studies.

    How do these flood studies contribute to flood management in Lake Macquarie?

    This project improves our methods of floodplain management and forward planning through tailored flood controls and accurate flood planning levels in the study areas. It will provide valuable information about appropriate areas of residential growth and development and identify properties that are potentially affected by flooding events, but are located outside the extent of existing flood studies. 

    On completion, Council will have a better understanding of flooding over approximately 98 per cent of the flood-liable lands in the City. The study for each identified tributary catchment will utilise appropriate hydraulic modelling and a history of past flooding to identify areas with flooding concerns. The results of this study, combined with land zoning and growth plans, will enable Council to identify areas that are flood affected and those which may require more detailed assessments of flood risks, which will be undertaken on a priority basis.

    What is the effect of lake flooding and sea level rise?

    The flood studies will consider the impacts of climate change upon flood levels for the rainfall increase scenarios and the effects of elevated water levels in Lake Macquarie waterway due to sea level rise. 

    Who is invited to participate in the studies?

    • Residents within the flood study boundaries surrounding the minor tributaries are encouraged to provide feedback. 
    • It is open to anyone who is interested flood management in the study catchment area, or more broadly, Lake Macquarie.

    Who can I contact for more information?

    Rhys Hardwick Jones or Richard Dewar, WMAwater

    Phone 02 9299 2855 or email lakemac@wmawater.com.au


    Greg D Jones, Senior Sustainability Officer

    Phone 02 4921 0406 or email gdjones@lakemac.nsw.gov.au