Retford Farm, Bowral - Stormwater Detention Basin

Project typeCapital Project with External Funding
Project value$6,150,000
Project scheduleEstimated completion March 2025
Contractor nameWestern Earthmoving Pty Ltd

Retford Farm Detention Basin updated photo montage - view north

Progress Update April 2024

Works are progressing with the Retford Farm Detention Basin Construction Phase.

Currently, the works are 50% complete, and as such, the embankment wall and project provided an unmeasurable amount of flood mitigation during the rain event of Friday 5 - Saturday 6 April.

Council looks forward to finalising the works and the outcomes the project will provide, in relation to flood mitigation along Mittagong Creek and through the township of Bowral.

Council is also pleased to announce that we have recently awarded an additional scope item for inclusion in the works by the Principal Contractor – Western Earthmoving.

This additional scope will include the construction of an outlet modification in the form of a weir on the upstream side of the piped concrete culvert. The weir will provide further flood mitigation, down to a 0.5EY (1 in 2-year) flood event and reduce flood level downstream of the Detention Basin site.

Progress Update February 2024

Wingecarribee Shire Council has secured more than four and half million dollars from the Australian Government to assist in the construction of the Retford Farm Detention Basin. The Detention Basin is a major component of the Bowral Floodplain Risk Management Strategy (FRMSP) first adopted by Council in 2009 and will significantly reduce the impact of future flooding events on the Bowral Township. Located on the eastern side of Old South Road at the Merrigang Street intersection, the Detention Basin will store approximately 320 mega-litres (320 million litres) of stormwater during high rainfall events.

The Basin will be formed by constructing an earthen embankment wall across Mittagong Creek, approximately 430m long and up to approximately 6m high, with a concrete culvert through the wall to allow ordinary creek flows out of the Basin during low rainfall events (note this culvert is not shown in the artists impression image). The finished wall will be grass covered to blend in with the surrounding natural environment. The area proposed to be excavated to obtain the material for the earthen embankment wall, will form a permanent pond adjacent to Mittagong Creek upstream of the existing weir.

Construction on the Retford Farm Detention Basin commenced in August 2023.

Retford Park Media Release(PDF, 262KB)
Retford Photomontage(PDF, 4MB)
Retford Farm Detention Basin Site Layout(PDF, 3MB)
Retford Farm Detention Basin – REF(PDF, 5MB)
Retford Farm Detention Basin – Fact Sheet 1(PDF, 611KB)
Retford Photomontage - North View(PDF, 2MB)