Why is the Floodplain Risk Management Study and Plan being reviewed?

    We make computer models and maps that show where it could flood and by how much. From time to time, these models are reviewed and predicted flood levels may change. The reasons why can include: 

    • New floods occur, providing additional data to fine-tune the model. 
    • More advanced computer models or methods for estimating flood levels become available. 
    • Changes in the catchment, such as flood mitigation works or new developments. 
    • Changes in policy. 

    After we update flood models, we also need to update our understanding of what the risks/damages from floods might be. We then need to update our plan for mitigating (reducing) these. This is what a floodplain risk management study and plan does. It has a prioritised plan of recommended measures to best address existing and future flood problems in the catchment. It also includes guidelines for all future developments in the area.

    What are the recommended measures for the Collins Creek catchment?

    Included with this information is a map showing the locations of some of the options recommended by flood engineers to help reduce flood impacts. They’ve been prioritised by how easily they could be done and the benefits they’re likely to have, e.g. if an option is simple to do and has great benefit, it’s given a high priority. These are the options that are location-specific. 

    WC3 Hospital Rd culvert trash rack, Bulli
    This trash rack would catch debris before it gets into the culvert, preventing blockages that raise water levels upstream and increase the risk of flooding downstream properties, including a preschool. It would be designed to let water flow freely while trapping large debris. 

    FC1 Hollymount Park channel upgrade, Woonona
    The existing channel/swale on the southern side of Hollymount Park would be made bigger and the stormwater inlet that’s along it would be improved. This should allow it to carry more water, reducing the risk of it overflowing and flooding nearby properties on Kathleen Crescent. 

    BG1 Princes Hwy detention basin, Russell Vale
    The existing flood detention area would be upgraded by raising the walls of the basin, either with dirt or a wall, so it can hold more water. The culvert under the highway will be adjusted to reduce the rate of water flow from the basin through downstream properties. 

    FC3 Memorial Dr & York Rd culvert upgrade, Russell Vale
    Two culverts under York Road would be upgraded; one north and one south of the Terania Creek intersection. The creek channel beneath Memorial Drive would also be regraded so it slopes down towards the creek confluence (where the waterways meet up east of Memorial Drive and west of the railway line). This photo shows an example of a culvert and trash rack:

    Other recommended options 
    Other catchment-wide options recommended to help manage flood risk include: 

    • Development controls to ensure future development is appropriate for flood-affected land
    • General community education strategy 
    • Make property flood level information available 
    • Emergency response plans for flood-affected homes and businesses to ensure residents and business owners know what to do in the event of a flood  
    • Illawarra Flood Emergency Sub Plan updates 
    • Voluntary house raising or purchase for eligible properties 
    • Flood warning system 
    • Develop a vegetation management plan for nominated sections of creeks in public ownership 
    • Develop an interim Entrance Management Policy for Collins Creek and Bellambi Lake Catchments. This would guide how we manage the height of the sand berms located at the outlets of Collins Creek and Bellambi Lake.

    Where can I get information about flood levels on my property?

    We have historical flood level records and/or our completed flood studies for some properties, but not all. Please contact our Customer Service team on (02) 4227 7111 to find out what’s available for your property.

    Who can I talk to for more information about the Collins Creek Floodplain Risk Management Study and Plan?

    You can contact us by:

    We’ll also be holding a drop-in community information session. At this session, we’ll have information displays and maps showing the location of the recommended measures for managing flood risk. The flood engineers who are working on this Floodplain Risk Management Study and Plan will be there to answer your questions, explain what is being planned and how the proposed measures will help manage flood risks. There is no presentation, so you don’t need to arrive at the start – you can turn up at any time during the session. 

    When: Wednesday 6 March 2024, drop in anytime between 3:30pm – 6:30pm 

    Where: Bulli Senior Citizens Centre, 8 Hospital Rd, Bulli 

    If you’d like to learn more but are unable to attend the session, the report, information and survey are available on this webpage. You can also ask us questions via this webpage. The information is also available to view at Wollongong and Thirroul Libraries, with copies of the FAQ, map, survey and reply-paid envelopes available.

    Can you help with a flood, maintenance or development issue not related to this Study and Plan?

    The flood engineers working on this Study and Plan can only assist with queries relating to this. Council’s Customer Service staff can assist with other enquiries, such as: 

    • Building and development issues. 
    • Maintenance requests for drains, stormwater pits, creeks and rubbish in public spaces. 
    • Pollution in waterways, gutters or stormwater channels by materials such as sediment (soil, sand, silt and mud), building waste or plant matter.

    Report an issue by phoning 4227 7111 or lodge your request online.

    What happens next?

    After we’ve completed the Floodplain Risk Management Study and Plan, more work will be done to develop concepts and detailed designs for the recommended stormwater structures. We’ll take these out to the community to seek further input before the designs are completed.

    How will my feedback be used?

    At the end of the engagement period, we read and consider all feedback. We write a report about the engagement and what we heard. It is provided to the project team and used to inform the final Floodplain Risk Management Study and Plan report.

    How can I join the conversation?

    • Online  www.our.wollongong.nsw.gov.au                           
    • Email    engagement@wollongong.nsw.gov.au                                
    • Write    Locked Bag 8821, Wollongong DC 2500                
    • Phone  (02) 4227 7111                                      
    • Drop-in Information Session (no presentation)
      When: Wednesday 6 March 2024 - drop in anytime between 3:30-6:30pm
      Where: Bulli Senior Citizens Centre, 8 Hospital Rd, Bulli      

    If you’re d/Deaf or have a hearing or speech impairment, you can contact us through the National Relay Service. If you need an interpreter, you can contact us through the Translating and Interpreting Service on 131450. You’ll need to provide our phone number 02 4227 7111 for either service.