City of Parramatta - Draft Flood Study

2024 Project Update

City of Parramatta’s six-week public exhibition of the Draft Parramatta River Flood Study closed on 30 October 2023. The study attracted more than 20,000 page views and we are currently reviewing all contributions.

Some of the feedback received will require in-depth analysis and we are working with our flood specialists for detailed responses to be provided to each contributor.

Subject to the extent of the modifications made, it is anticipated that the Draft Parramatta River Flood Study will be presented to Council for endorsement in June 2024.

Once the flood study is adopted, work will then begin on the Draft Floodplain Risk Management Study and Plan. This study will investigate and identify appropriate flood mitigation actions that can be delivered to reduce or resolve flooding in areas with a high flood risk. When completed, the Draft Floodplain Risk Management Study and Plan will be presented to the community for feedback.

The Parramatta River is central to our City’s identity. The river is a gathering place for locals and visitors, and has been that way for thousands of years. The point along the river where fresh and salt waters meet, ‘the place where eels lie down’, is a place of great cultural significance.

From the earliest days, the changeable nature of the river has also meant risk of flooding. Today, our CBD is one of the most flash-flood affected areas in the country. Our challenge is to live with the river in all conditions, and to prepare our community for the risk of flooding.

Large parts of the Parramatta Local Government Area (LGA) are prone to flooding. Although the last big floods were in 1986 and 1988, there has been significant flooding in parts of the LGA in the past few years.

A new flood study and what it means for you

The NSW Government requires that all local Councils manage flood risks within their area.

One of the first steps in the required floodplain risk management process is to prepare a flood study which shows the extent of flooding up to the largest possible flood.

Details on the NSW Government requirements for flood modelling can be found at environment.nsw.gov.au/topics/water/floodplains/floodplain-guidelines

The City of Parramatta has commissioned a draft Flood Study. Using new technology, the draft Flood Study covers a large area of Parramatta (see maps below) and builds on previous studies.

The draft Flood Study uses modelling to demonstrate various sized flood events from the smallest to the largest possible flood. The draft Flood Study shows where water is likely to cause flooding and calculates its likely depth.

Council uses this information to make planning decisions, to protect the community, and inform flood mitigation works.

Homeowners are also advised if their property is subject to planning and development controls in relation to flooding.

More importantly, the new flood information will enable residents to stay safe and be better prepared to deal with flooding. Those likely to be greatly affected by flooding can make informed decisions around a flood and evacuation plan, and other considerations such as insurance.


What is a flood study and why do we need one?

A flood study, along with data collection, is the first step in understanding the flood risk in a Local Government Area (LGA).

A flood study is a technical investigation of flood behaviour and allows Council to identify the risks from different sized floods, from small floods up to the largest possible flood. The study models the likely path of floodwaters and the likely depth.

This helps in managing buildings across our City and Council assets, as well as in planning for future development. A flood study also helps keep our community safe.

A flood study helps emergency managers to understand local flooding and its possible impacts on people’s safety.

In addition to helping State Emergency Services, a flood study can be used by residents to gain a better understanding of flood risk to their property. Residents might use information in the draft Flood Study to develop their own flood response plan that they can use to protect themselves and reduce flood damage. The NSW SES provides information on preparing a flood plan - visit ses.nsw.gov.au/disaster-tabs-header/flood


What does the draft Flood Study tell us?

Modelling of the local catchment system, including overland flooding, is the key to improving Council’s existing flood information. Overland flooding is flooding caused by water flowing over land caused by local runoff during and after rain, perhaps from drains and stormwater systems, rather than overflowing water from a river, stream or dam.

A flood study provides Council with an understanding of flood risk so it can manage existing development and plan for future development.

The draft Flood Study helps us determine where water flows in heavy storms, how deep the water can become, and how dangerous the flows might be. A flood study not only looks at the current flood risk but also future flood risks, including those that may result from climate change.

As flood modelling techniques have been updated, new technologies provide us with the ability to more accurately determine the hydraulic flood conditions within the catchment area.

Flood models now map mainstream flooding from rivers and creeks and also examine flooding that can come from local stormwater drains and from the local overland catchment.

This draft Flood Study has provided the opportunity to use new 2D flood modelling software to better determine the behaviour of flood water.

Flood studies also help emergency services (e.g. NSW State Emergency Services [SES], Police) to better understand the impacts on people’s safety when various levels of flooding occur, and help landowners to understand their flood risk so that they can be better prepared for flooding.

Is my property flood affected?

Around 12,378 land parcels have been identified as having a flood risk. Risks vary across the LGA - it is important that you are aware of potential flooding to your home.


Flood maps and videos

Council has produced a series of maps and two videos to help you better understand the draft Flood Study:

  • A maximum probable flood map showing the largest possible flood
  • A 1% AEP (Annual Exceedance Probability Flood) map showing the flood inundation area
  • A hazards map which indicates the different flow hazard conditions for both the 1% AEP flood event and maximum probable flood

Accessing the maps and videos

Hover over each tile below to flip them around and click on the buttons to see the videos as well as draft flood modelling for your home and/or other locations that you may be interested in.

Once you have accessed the relevant map, you can search for your address by clicking on the magnifying glass icon in the top righthand corner of the page.

Please also note that the current version of each flood map is positioned to the left of the slider and the proposed version of each flood map is positioned to the right of the slider. The colours used to represent different levels of flood depth also vary between the current and proposed flood maps.

General Disclaimer – Flood Studies and Plans: While every effort is made by City of Parramatta Council to ensure that accurate information is circulated via this website, Council does so in good faith and makes no representation or gives any warranty about the content, suitability, or accuracy of the information for any purpose. Click here to read the full disclaimer.

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MAP 1: Probable Maximum Flood (PMF) - Floodprone land

MAP 1: Probable Maximum Flood (PMF) - Floodprone land

TO ACCESS THE INTERACTIVE MAP

>> CLICK HERE <<
MAP 2: 1% Annual Exceedance Event (1:100 year flood) - Floodprone land

MAP 2: 1% Annual Exceedance Event (1:100 year flood) - Floodprone land

TO ACCESS THE INTERACTIVE MAP

>> CLICK HERE <<
MAP 3: Probable Maximum Flood (PMF) Hazard Profile

MAP 3: Probable Maximum Flood (PMF) Hazard Profile

TO ACCESS THE INTERACTIVE MAP

>> CLICK HERE <<
MAP 4: 1% Annual Exceedance Event (1:100 year) Hazard Profile

MAP 4: 1% Annual Exceedance Event (1:100 year) Hazard Profile

TO ACCESS THE INTERACTIVE MAP

>> CLICK HERE <<
VIDEO 1 - 2023 Draft Flood Study – Flythrough

VIDEO 1 - 2023 Draft Flood Study – Flythrough

TO WATCH THE VIDEO AND LEARN MORE ABOUT FLOODING IN PARRAMATTA AND THE FINDINGS OF THE 2023 DRAFT FLOOD STUDY

>> CLICK HERE <<
VIDEO 2 - 2023 Draft Flood Study – Animated Model

VIDEO 2 - 2023 Draft Flood Study – Animated Model

TO WATCH THE VIDEO AND SEE SOME OF THE NEW MODELLING WHICH FORMS PART OF THE 2023 DRAFT FLOOD STUDY

>> CLICK HERE <<

Feedback on the 2023 Draft Parramatta River Flood Study is now closed

Thank you to everyone who viewed our 2023 Draft Parramatta River Flood Study and/or submitted feedback. Covering most of the Parramatta Local Government Area (separate studies are in planning or underway for A’Becketts Creek Catchment, Haslams Creek Catchment, Hill Road – Wentworth Point and Devlins Creek Catchment) this study is the most significant update to flooding information in 20 years. 

The 2023 Draft Parramatta River Flood Study uses the latest technology and methodology to model flooding from rivers and creeks, and for the first time, it also illustrates the potential impacts of overland flooding – how water moves across our City in heavy storm events.

The flood study attracted more than 6000 unique views and over 100 submissions (online, phone, in-person).


What happens next?

The flood team will review all the material provided by the community and work with our specialist flood consultants to make adjustments to the flood model where appropriate. The flood team will also respond to everyone who raised particular concerns in their submissions.

In March 2024 the Draft Parramatta River Flood Study will be submitted to Council for endorsement. In the next stage of the project, after Council’s adoption of the study, City of Parramatta will begin a Draft Floodplain Risk Management Study and Plan which will investigate and identify appropriate flood mitigation actions that can be delivered to reduce or resolve flooding in areas with a high flood risk. It is expected this work will begin in 2024. When completed, the Draft Floodplain Risk Management Study and Plan will be presented to the community for feedback, as will other draft flood studies.      

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