Stonequarry Creek Works completed by Wollondilly Shire Council

Warragamba Panorama

Stonequarry Creek Works completed by Wollondilly Shire Council

Posted on: 05.03.2019

Wollondilly Shire Council has been surprised by a recent announcement from NSW Treasurer Dominic Perrottet and NSW Liberal candidate Nathaniel Smith that they will campaign for State Government funding for Stonequarry Creek to “deliver flood mitigation.” They have stated that, “The construction of a path and cleaning out of the creek will assist with flood mitigation and protect businesses and residents of Picton from flood incidents like what occurred in 2016."

Mayor, Councillor Matthew Deeth said, “Sections of Stonequarry Creek were damaged as a direct result of massive rainfall event that occurred in June 2016, the largest in Picton since 1856 as far as records show. This resulted in flooding across this catchment and others in Wollondilly. Council has addressed the flooding hazard in Picton in numerous ways.”

In the clean-up following the 2016 storm event, a massive amount of work was done to clean up debris and repair the creek banks, all funded by Council. Since then Council has carried out scheduled vegetation management at the creek each year. The clean-up and ongoing vegetation management has been guided by experts from the State Government, however there has not been any financial assistance from the State Government.

Additionally, Council, in accordance with the State Government Flood Prone Land Policy and with the assistance of the State Government’s Office of Environment & Heritage has been pursuing a Floodplain Risk Management Study and Plan for this catchment. This will look at options to reduce the impacts of flooding, including: appropriate development controls; community education & awareness; ongoing vegetation management and potentially, civil works that may help minimise the risk.

As such, the State Government is already giving support to Council for the assessment of flood mitigation options and will likely support any option that is proven to have merit, given the State Government’s long established Floodplain Management Program.

Council also maintains a flood warning system that monitors the creek and rainfall conditions and has been promoting flood education since the 1990’s.

Mayor Deeth said, “The Picton town centre is built on the Stonequarry Creek floodplain, which is part of the amenity and feel of Picton. Unfortunately, even with all the work Council has done, this means that there is a risk of flooding and previous studies have confirmed this risk.”

Council has already done a significant amount of work cleaning out the creek, and the current levels of vegetation are below what would be deemed ‘natural’ and are at the minimum necessary to keep creek banks stable in times of significant flow. Further loss of vegetation exposes the community to creek banks that could quickly wash away leaving adjacent homes and public infrastructure vulnerable.

Mayor Deeth noted, “We would welcome any State funding to help manage the floodplain, particularly if it buys back privately held land along the creek.

“At the end of the day, we want a commitment to funding and not an election stunt or another petition.”

Since June 2016, Council has completed the following vegetation works (vegetation thinning, vegetation debris removal, weed control):

  • June 2016 - (100 hrs contractor time) + crown lifting
  • July 2016 - (192 hrs) + crown lifting
  • September 2016 – (162 hrs)
  • November 2016 (73 hrs)
  • December 2016 (56 hours)
  • March 2017 – (21 hrs)
  • July 2017 – (80 hrs)
  • May 2018 – (64 hours) + opening up the channel behind the townhouses in Menangle St
  • June 2018 (96 hrs) – control of weed

The NSW Soil Conservation Service also undertook work for Council (funded by Council) including:

  • March 2017 – tree removal and bank stabilisation
  • November 2017 – Stonequarry Creek River Process and Erosion Report complete
  • August 2018 – Casuarina tree relocation to more stable position

Further information on Council’s Floodplain Risk Management Program is available on the Council website: https://www.wollondilly.nsw.gov.au/resident-services/water-management/floodplain-risk-management?stage=Live