A report for a South Coast council looked at flood behaviour within a catchment. Photo: Bega Valley Shire Council.
Bega Council has adopted a new flood plan for an area earmarked for more development and to include affordable housing.
The Wolumla Flood Study examined flood behaviour within the Wolumla Creek catchment and its tributaries, Frog’s Hollow and Greendale creeks.
At its recent meeting, Bega Valley Shire Council (BVSC) voted to adopt the study’s findings.
“No prior flood study has been undertaken for the catchment, and available flood intelligence has been limited, relying primarily on anecdotal historical observations,” the study reads.
The Wolumla Creek catchment is located within the larger Bega River catchment.
The former discharges to the Bega River, with the Wolumla Creek confluence located about 10 km upstream of the Bega township.
The 2021 census data showed about 6.7 per cent of the Bega Valley Shire’s residents lived in rural areas surrounding Bega (which includes that catchment).
“Development is relatively dispersed across much of the catchment, typically involving a small number of structures on a large parcel of land,” the study found.
“The exception is the Wolumla township, which has a greater development density.”
In June 2024, councillors adopted the Wolumla Structure Plan, which investigated how existing vacant urban release areas could be developed to accommodate about 1000 new homes and how these could be integrated with the village.
During the discussion on the study’s adoption, Mayor Russell Fitzpatrick raised his concern about whether the flood study covered the area examined in that plan.
“I always saw this [as], ‘We need to do this report … as part of our development of the Wolumla Structure Plan’, and yet here it appears the structure plan is not covered by [it].”
In response, CEO Anthony McMahon said that while the flood study was part of the work council needed to do as part of the planning process, other plans would consider that in more depth.
“[My] interpretation of that is that because the development hasn’t occurred, it means that the impacts of that development on the overall flood modelling are really difficult to consider at the moment,” he said.
“In other words, when you do a development, it changes the land form, which then changes the outputs in a model like this.”
The study also noted that flooding in the area was caused by rainfall (the most common cause for the Wolumla township), mainstream flooding and overbank flows from creeks (a majority of flooding in the study area) and backwater from the Bega River.
During the meeting, Councillor Helen O’Neil described the document as a needed step towards increasing housing in the area.
“[This] is an essential next step in providing a greater housing supply in our area, particularly for those who want more affordable housing,” she said.
“I’m glad we finally got it … There’s also a lot of anxiety in the area about floodplains’ impact on development, so this provides a very good base for data for future analysis.”
The document’s adoption means it will become the key technical document for the subsequent Floodplain Risk Management Study and Plan (FRMSP).
This allows for improved planning around land use, infrastructure and emergency responses, according to the council’s agenda.
Both the study and an FRMSP were made possible through grant funding awarded to BVSC. The document was prepared by consulting firm Rhelm Pty Ltd for the council.
The Wolumla Flood Study is available in the meeting agenda, and it will also be published on BVSC’s website.
