Wollongong has complex flooding behaviour. The escarpment and Royal National Park to the west and north of the city presents significant flash flood risk, while areas to the east and south along our coastline and around Lake Illawarra can experience coastal and tidal inundation events.
We have long established technical advisory committees for flooding whose purpose is to assist Council and its consultants develop plans that help us understand potential flood behaviour in specific locations – or catchments – right across the city. These plans also meet NSW Government requirements. Information relating to the committees can be found on our website.
The committees are made up of residents of the specific catchment areas, flood action groups, neighbourhood forums, key State Government agencies, and up to three Wollongong City Councillors. Each committee assists with the development of the relevant plans within their catchments from its inception to the final draft. The committee then provides a recommendation for the Council to adopt the final draft of the Flood Risk Management Study and Plan (FRMSP). Those Councillors, who are not on the committee are able to be briefed on the content of the draft, prior to a Council meeting, and access is facilitated to subject matter experts, if needed. The FRMSP can be anywhere from 400 to 1000+ pages of detail and maps which is why an executive summary and recommendation from the technical advisory committee is tabled at the Council meeting.
The documents related to floodplain management are complex and are interrelated. The Flood Study, which is completed first after a data collection phase, informs the Flood risk Management Study and Plan, and then these documents allow for the planning and delivery of flood mitigation infrastructure.
Throughout the life of all these documents, Council will continue to monitor and respond to new flooding events and consider the implications of observed and modelled flood behaviour in our work. The recommendation for adoption for the Fairy Creek and Cabbage Tree Creek and Allans Creek FRMSP from the flood committee occurred on 3 April, just days before a natural disaster. Following the 6 April storm event, Council received photos, videos, and flood information throughout the local government area from various sources, including affected residents. Council officers were also on the ground collecting data about flood marks at critical locations to test against the flood model. Validation of the models confirmed the flood behaviour occurred in line with the modelling used to inform the final Plan/s for these catchments. This supported our approach undertaken to move forward with the FRMS&P, as there were no tangible benefits in delaying the FRMS&P.
Council was required to review all FRMSP after the adoption of Council stormwater blockage policy in 2016. Over the next 18 months we are aiming to complete most of the catchments' FRMSP which will allow us to focus on the implementation of these plans with the committees. The FRMSP's need to be adopted by Council before we're able to move forward with any recommended implementation measures including properties that are eligible for Voluntary Purchase Schemes and Voluntary House Raising schemes.
This is something we have heard loud and clear from our community since April 6, complete the planning and deliver on the flood mitigation infrastructure. Over the next four years $26 million is allocated to improve floodplain and stormwater management across Wollongong. This will go towards new floodplain management assets, new and renewed drainage, and other projects. With additional financial support from the State Government, we could increase this delivery on the FRMSP infrastructure actions.
