Please share your experiences and records to help update our understanding of flooding in the Narellan Creek Catchment
This valuable information will help us to:
- Prepare an overland flow study for the catchment;
- Confirm the location of flooding problems and identify where flood mitigation measures (e.g. stormwater upgrades) may be best implemented to reduce the impact of flooding on the community;
- Assist with emergency management and guide future development and re-development so that it is compatible with the flood risk; and
- Guide the development of a computer flood model of Narellan Creek Catchment. This computer model will be used to simulate the movement of floodwater across the catchment for a range of flood sizes.
Get involved
People with experience of flooding in the Narellan Creek Catchment are invited to:
- Chat with us at a community drop-in session held on Wednesday 21 June 2023 from 1pm to 4pm at Narellan Library, corner Queen and Elyard Streets, Narellan.
- Book an online chat on the evening of Wednesday 21 June 2023 — RSVP here
- Complete a survey and share flooding details including flood depths/heights by 3 July 2023 ↓
- Submit flood photos and videos using the mapping tool below ↓
If you have any questions or require assistance with providing information, please contact:
- David Tetley, Catchment Simulations Solutions on 02 8355 5501
- Floodplain Management Team at Camden Council on 02 4654 7777 or mail@camden.nsw.gov.au
Survey
The survey should only take about 10 minutes to complete. Please try to answer as many questions as you can and give as much detail as possible.
HANDY TIP: A PDF of the questions has been provided for you to prepare responses ahead of time so it is quick to copy them across in one go. If you'd like to save your response part way through please ensure you are signed in as a registered member of Your Voice Camden.
Once completed we will send you an email to confirm receipt.
Map your experience or photos
Catchment
This map shows the various rivulets and creeks which flow in the Narellan Creek Catchment.
Narellan Creek catchment covers an area of 35 km2 and includes the suburbs of Narellan, Narellan Vale, Mount Annan and parts of Harrington Park, Gregory Hills, Kirkham and Elderslie.
The Catchment includes Narellan Creek as well as the following tributaries:
- Oxley Rivulet
- Herbert Rivulet
- Condron Creek
- Campbell Rivulet
- Cross Creek
- Howe Rivulet
- Thornleigh Gully
- Annan Creek
- Kenny Creek
The extent of the catchment is shown in yellow in the image above.
During most rainfall events across the catchment, runoff is carried by the stormwater system into the various creeks. However, during periods of heavy rainfall there is potential for the capacity of the stormwater system (underground pipes) to be exceeded.
The excess water that travels along roads and potentially through properties is referred to as overland flooding (it can also be referred to as flash or stormwater flooding).
Overland flooding has been experienced across parts of the catchment in June 2016, February 2020, March 2021, March 2022 and July 2022.
FAQ
The Narellan Creek catchment covers an area of 35 km2 and includes the suburbs of Narellan, Narellan Vale, Mount Annan and parts of Harrington Park, Gregory Hills, Kirkham and Elderslie.
The Catchment includes Narellan Creek as well as the following tributaries:
- Oxley Rivulet
- Herbert Rivulet
- Condron Creek
- Campbell Rivulet
- Cross Creek
- Howe Rivulet
- Thornleigh Gully
- Annan Creek
- Kenny Creek
The extent of the catchment is shown in yellow in the image below.
During most rainfall events across the catchment, runoff is carried by the stormwater system into the various creeks. However, during periods of heavy rainfall there is potential for the capacity of the stormwater system (underground pipes) to be exceeded.
The excess water that travels along roads and potentially through properties is referred to as overland flooding (it can also be referred to as flash or stormwater flooding).
Overland flooding has been experienced across parts of the catchment in June 2016, February 2020, March 2021, March 2022 and July 2022.
An overland flow study is a type of flood study that focusses on the movement of floodwater across urbanised areas. It is completed with the help of computer flood models to simulate a range of flood sizes in the catchment. The computer flood models are developed to include a representation of all key features that influence the movement of water across the catchment, such as the stormwater drainage system, bridges and culverts.
However, it is critical that the computer flood models are calibrated and verified to ensure they are providing reliable flood information. This is achieved by comparing the flood model results against recorded information from historic floods. This historic flood information can include rainfall amounts, water levels/depths as well as descriptions of flooding provided by the community.
The study will help define overland flow behaviour under current and future climate conditions. This technical information helps to understand the flood risk and serves the basis for investigating flood risk management options in future floodplain risk management studies and plans.
Camden Council has engaged flood specialists Catchment Simulation Solutions to prepare a detailed overland flow study for the Narellan Creek catchment. This project is supported by the NSW Government’s Floodplain Management Program.
Camden Council has completed several flood-related investigations for the Narellan Creek catchment. This has most recently included the Updated Narellan Creek Flood Study (2017). However, these previous studies only included a representation of major trunk drainage pipes. Therefore, the full stormwater system was not included and, as a result, overland flooding was not well represented. Furthermore, large areas of the catchment have undergone significant development meaning the previous studies no longer provide the best possible understanding of the flood risk across all parts of the catchment.
Community input has an important role in the study. It helps us understand your personal experiences from past flood events and helps to ensure the computer flood models that are developed for the study reflect these experiences.
A flood survey has been posted to affected property owners within the Narellan Creek Catchment area.
People with information about flooding in this area are encouraged to complete the questionnaire by the 3 July 2023.
Photographs of flooding events can help illustrate the flooding history and assist us to understand possible trends. These can be uploaded using the mapping tool.
To speak in-person to a representative from Catchment Simulation Solutions or Camden Council, please come along to a Community Drop-in Session which will be held on 21 June 2023 at the Narellan Library at the Corner of Queen and Elyard St, Narellan. This will provide you with an opportunity to ask questions about the study and to share your flooding experiences.
If you can't attend the drop-in session and have questions or require assistance with providing information, please contact:
- David Tetley, Catchment Simulations Solutions on 02 8355 5501
- Floodplain Management Team at Camden Council on 02 4654 7777 or mail@camden.nsw.gov.au
