The north of Byron Shire was, once again, seriously impacted by recent flooding and there are several community groups taking action and calling meetings to look at possible solutions and the development of resilience in these communities.
Around 200 people came together at the Ocean Shores Country Club last Tuesday, 26 April to discuss the effects of flooding in the north of Byron Shire hosted by Ocean Shores Community Association (OSCA).
‘The focus of our meeting was to gather both the “flood affected” and the “flood concerned”, to activate our community on a positive pathway forward, and to kick off a coordinated approach towards working with both Council and State government,’ said Francesca Esposito, spokesperson for OSCA.
‘This group has asked Council to kick into action any immediate steps that they are able to take to help mitigate imminent flooding, including clearing drains, which haven’t been fixed for years, fixing sewerage pipes, dredging the waterways and opening outlets to the sea.’
The potential mitigation of flooding by dredging, dune openings, and removal of rock walls was investigated following the Ex-Cyclone Debbie flooding in 2017 in the North Byron Floodplain Risk Management Study 2020 (NBFRMS). Unfortunately, the modelling did not support the desired reduction in flood impacts expected by the community from these actions.
Four dune openings were investigated at Wooyung, two at South Golden Beach (SGB), and one south of New Brighton. The study found that reductions in flood levels ‘are not substantial and range from approximately 0.05m in Brunswick Heads and New Brighton to 0.1m in Ocean Shores. Furthermore, during an ocean-dominated event, flood levels may in fact increase as a result of the openings’.
Like the dune openings, the rock walls at the mouth of the Brunswick River are often suspected of increasing flood levels by slowing the release of flood water. However, it is important to recognise that the walls also act as a barrier to sea surges coming into the rivers and increasing flooding.
The NBFRMS found that ‘In the one per cent AEP [Annual Exceedance Probability] event this option [rock wall modification] had no impact on flood levels, as the walls are already submerged in larger flood events and therefore modification is not shown to improve flooding in the area’.
Dredging was considered for 3km along the Brunswick River at Mullumbimby and for approximately 7.5km along Marshalls Creek from just to the east of the Pacific Motorway Bridge near Billinudgel down to the confluence of Marshalls Creek with Brunswick River.
The Study noted that ‘dredging is a temporary solution and to be effective requires considerable ongoing costs to dredge on a regular basis… Dredged material can be hazardous… and environmental impacts can include disruptions to the natural ecosystem such as affecting the health of aquatic species, water quality and also impact bank stability increasing potential erosion’.
Coupled with this was the minimal impact it would have on the actual flood levels.
For the nearby tributaries, Chinbible Creek, Mullumbimby Creek and Saltwater Creek the modelling showed ‘a maximum decrease in flood levels of potentially 0.12 m in the Mullumbimby Community Garden and only approximately 0.05m in Mullumbimby’.
The dredging of Marshalls Creek showed ‘a maximum decrease in flood levels of potentially up to 0.05m in Ocean Shores and New Brighton and 0.01m in South Golden Beach’.
The next OSCA run community meeting is on Tuesday 10 May at the Ocean Shores Country Club from 6pm.
Community resilience meeting
The community resilience network for SGB, New Brighton and Ocean Shores, who coordinated a community volunteer flood response hub at SGB Hall, are calling a community flood meeting 15 May at Ocean Shores Public School Hall at 3pm for local residents.
‘As part of our flood hub we calculated that 1,100 dwellings were affected by floodwaters in some way. Communities will always be first responders so it is really important that we are as ready as we can be,’ said spokesperson Rebecca McNaught.
‘The event we are holding is open to all ideas people have on what happened and how we can develop solutions to build our community resilience. The community response was amazing and people chipped in any way they could.
‘This is about creating a voice to engage with the response and recovery agencies who are really open to community-led responses.’
The resilience meeting will start with small focus group discussions. There are also a kids and youth space with craft and sports activities and then the evening will be rounded out with a catered dinner. Zoom options are available for people who are unable to attend in person. For more information call Rebecca Rebecca on 0412 933 212 or email: [email protected].