Frequently Asked Questions

Flooding is a relatively rare event.  It is characterised by the overtopping and inundation outside of natural rivers, creeks or artificial channels.

There are 3 types of flooding that can affect Newcastle including:

1. Flash Flood - Intense rainfall over the local catchment making runoff that exceeds the capacity of the drainage network causing flooding quickly and with limited warning. These floods are common for the local waterways in Newcastle such as Throsby, Styx, Cottage, Dark and Ironbark Creeks.
2. Hunter River Flood - Sustained heavy rainfall in the Hunter River catchment causing high river levels that spill out into the floodplain. These floods are common along the low lying areas adjacent to the River such as Hexham, Beresfield and Sandgate.
3. Storm Surge - Oceanic storms on the coast causing elevated water levels, severe winds and large waves. These floods are common in Newcastle Harbour and low lying suburbs such as Stockton, Carrington, Wickham, Maryville and Islington.

These events can occur independently or in combination. It is not possible to predict exactly when or how severe a flood will be, however our weather forecasts can make predictions. The first of the three above is difficult to predict because it is a result of locally occurring storms and the response time from the onset of intense rainfall to the flood is short (i.e. less than one hour). Therefore it might be difficult for the local media to broadcast warnings for flash flooding. The second and third mechanisms have longer response times and it is then expected that better warning could be broadcasted for these events.

Flooding which is sudden and unexpected as a result of heavy rainfall in local catchments.

Land that has been formed by flooding over time. Much of Newcastle has been built on floodplains. This was evidenced in the floods of June 2007.

Overland flow occurs when runoff from heavy rainfall runs across the land either before it enters a waterway or after a waterway breaks its banks. Overland flow tends to affect localised areas during flash flooding.

Land that would be affected by the probable maximum flood. Only land that is above these levels is truly flood free.

Note - The insurance industry has its own definitions of flooding (and stormwater) and you should make your own enquiries about how your insurance company classifies flooding (and stormwater), and how this relates to your insurance provisions.

A Plan of implementation actions adopted by Council to reduce the risk of flooding in a subject area as defined by a Flood Study.

A detailed investigation into the flood behaviour of a catchment and production of maps to define the extent, depth and velocity of flooding for a range of flood events.

Local drainage refers to the pit and pipe network that drains urban areas to the nearest creek or open channel. The network is only designed and intended to manage more frequent rainfall events than rare floods. That is to say that every now and then, it is normal for street drainage systems to overflow.
Local drainage problems can occur anywhere and are not included in City of Newcastle’s floodplain management planning. However if the street drainage system is overflowing more regularly, there may be a problem that we need to have a look at, you should write to City of Newcastle to describe the problem and we will respond to your request.

City of Newcastle is working on identifying areas where additional pits or pipes may assist with flooding. Once identified, it would be prioritised in the works program.

Making decisions and undertaking a broad range of activities on a floodplain to ensure flood risks are identified and managed.  There are many different aspects of floodplain management. These include:

• convening a Floodplain Management Committee to steer floodplain management in a given area. This should include stakeholders of local government, state government departments and community representatives

• calculating flood information such as heights, extents and potential risks to life and property of flooding, including estimating the effects of possible future climate change and sea level rise

• finding and evaluating complete systems of managing the risks, which would include consideration of emergency management, examining if it is feasible to reduce the flooding, looking at ways of living with the risk, and how to manage future development

• consulting with the community when planning for floods

• the elected Council adopting a Floodplain Risk Management Plan

• finding the funding and resources needed to implement this Plan over time.

Flooding is a natural random event that occurs in all parts of Australia. In general, flooding is a rare event. The nature of flooding may change with possible future climate change and the changes that human activity makes to catchments and topography.  

Flooding can result in property damage and even loss of life. Newcastle and its suburbs was built on natural floodplains so from time to time during times of very heavy or extreme rainfall, nature reclaims these areas.

Flood management is a shared responsibility. Owners and occupiers of flood prone properties are required to play a significant role in flood awareness, preparedness of your property and appropriate flood response.

Management of large scale (and generally rare) flood events is a shared responsibility between Government and the community.

The SES are the combat agency for dealing with flood response and recovery and the preparation of Local Flood (emergency) Plans to guide the actions in the management of floods when they occur. Councils also assist with recovery efforts post flood to ensure affected public assets are safe and waste is collected from flood affected properties. Councils do not have the lead role in the combat of floods when they occur, this is the sole responsibility of the SES.

Councils are responsible for the preparation of Floodplain Risk Management Plans to identify the level of flood risk and what options are available for risk management.

Flood proofing Newcastle by attempting to prevent floodwaters from entering the floodplains on which much of Newcastle has been built is an impossible task. The city’s drainage system was only designed to cope with frequent rainfall. Trying to build a drainage network to prevent flooding in Newcastle would require massive changes to the city that would make many suburbs unrecognisable.  For example, to prevent flooding in the commercial area of Wallsend during an extreme flood event would mean widening the existing storm channel from 17m to 120m and building one metre high containment walls along its length.

This is not a reasonable solution as it would severely affect the suburb’s business district and would probably transfer the problem downstream.

Only land that is higher than the probable maximum flood is completely flood free. Many properties which were not flooded in June 2007 may be flooded in different floods in the future. To find out if your property is potentially flood affected you can view the maps of the City Wide Floodplain Risk Management Plan or apply for a Flood Information Certificate.

The PMF is the largest flood that could possibly occur. It is a very rare and improbable flood. Despite this, a number of historical floods in Australia have approached the magnitude of a PMF.
History has shown that extreme flood events can and do happen (eg. the November 1996 flood in Coffs Harbour, the August 1998 flood in Wollongong and Dungog in April 2015).

All floods are different. We do not know when the next flood will occur, or how big it will be. But we can estimate what the likelihood of a certain size flood are based on historical data. So for example, if your area has had a (so called) '1 in 100 year' flood, it is a fallacy to think you will need to wait another 99 years before the next flood arrives. Floods do not happen like that. Some parts of Australia have received a couple of '1 in 100 year floods' in one decade.

We should better refer to a flood that has a 1 in 100 chance of occurring in any given year, or a flood that has a 1 in 10 chance of occurring in any given year – and so on.

In general, a property can have a physical risk of flooding, yet not be classified as ‘flood liable’ by City of Newcastle’s Flood Policy. This could occur because a Council’s knowledge of potential flood risks needs to be gained by undertaking a Flood Study.

In 2004, the elected Council adopted a Flood Policy. This then legally enabled the identification of properties affected by the Flood Policy. A property is affected by the Flood Policy if it is wholly or partly within City of Newcastle's estimate of the PMF.

Our knowledge of the extent of potential flood risks has been growing over many years as Flood Studies have been carried out over the Local Government Area. While the June 2007 flood event confirmed City of Newcastle's flood maps of potential flood risks in many areas, it has not been found necessary to change mapping of potential flood risks as a result of these floods.

If your property is identified by City of Newcastle as being in a flood affected area, the real flood risks on your property have not changed, rather, present estimates of the risk as identified by City of Newcastle are available to assist and inform decision making.

Ultimately, the market determines the value of any property. Individual owners should seek their own valuation advice if they are concerned that the flood risk estimation available from City of Newcastle may influence their property value.

Yes. The information used by Insurance companies to offer flood insurance and set premiums has been supplied by City of Newcastle to the Insurance Council of Australia. This information has been prepared through the various Flood Studies undertaken by City of Newcastle.

You should confirm the specific details of your current insurance situation about flooding directly with your insurer.

Property owners who are concerned about their ability to obtain a loan should clarify the situation with their own lending authority.

Clearing creeks will enable more water to flow but will not prevent flooding during rare floods. Creeks can only take so much water before they overflow regardless of any debris or vegetation. During rare floods the whole of the floodplain is activated and more water flows on the floodplain than in the creek or river.  Vegetation is an important part of a natural creek because it provides habitat and holds the creek banks together resisting erosion.