Council seeks feedback on Floodplain Risk Management Plan

Warragamba Panorama

Council seeks feedback on Floodplain Risk Management Plan

Posted on: 28.03.2018

Wollondilly Shire Council is seeking feedback from the community to help in the development of the Floodplain Risk Management Plan for Stonequarry Creek.

Mayor Judith Hannan said, “Picton, especially the town centre, has a long history of flooding due to its location within the Stonequarry Creek floodplain.”

“Council’s understanding of flooding and associated risks at Stonequarry Creek needs to remain up-to-date so we can be proactive in managing risks to the community,” she said.

The current Stonequarry Creek Flood Study, undertaken by Council’s consultant Advisian, helps to advise the community about flooding behaviour and risks as well as informing the flood levels Council will adopt for the area.

Since flood recordings began in 1956 there have been approximately nine serious floods that have impacted Picton, according to the Study. A number of flood studies have previously been completed on Stonequarry Creek, looking at flooding behaviour in the area to assist in identifying the appropriate controls for development to minimise flood risk.

Flood levels help guide Council’s processes when it comes to the development of land within a flood prone area to ensure housing heights and floor levels are appropriate to minimise impacts of flooding risks in the future.

The 1% AEP (Annual Exceedance Probability) Flood is a flood that has a 1% chance of being equalled or exceeded in any one year and can also be known as the ‘one in 100 year’ flood. The study estimates that the 1% AEP flood level would generally be up to 200mm higher than the current adopted 1% AEP flood level, depending on the location within the floodplain.

Typically, for new development, a buffer of 500mm above the predicted flood level is added to determine a ‘flood planning level’ to ensure a level of protection is achieved and allows for variations due to uncertainties and localised variations.

The Stonequarry Creek Flood Study is on public exhibition until 27 April 2018 and can be viewed online at or at Council’s Administration Building (62-64 Menangle Street, Picton) or Wollondilly Library (42 Menangle Street, Picton).

Council is also running a survey until 27 April 2018 to better understand the community’s views and ideas about managing the risks relating to flooding in Stonequarry Creek. You can complete an online survey by visiting  or by requesting a hard copy of the survey from Council.

A community drop-in session will be held at 3pm-8pm on 10 April at the Wollondilly Shire Hall, 44-60 Menangle Street Picton for anyone who would like more information about the Stonequarry Creek Flood Study, give feedback on the study or complete the survey about possible flood management options.

If you would like any further information about this project contact Council’s Investigation and Design Engineer on 4677 1100 or