Narellan Creek Overland Flood Study (Vol 1) - Flipbook - Page 30
Narellan Creek Catchment
Flood Study
2.7
Community Consultation
A key component of the flood study involved development of computer flood models. The
computer models are calibrated/validated to ensure they are providing a reliable
representation of flood behaviour. This is completed by using the models to replicate floods
that have occurred in the past (i.e., historic floods).
Only limited historic flood information is available for the catchment. However, it was
considered that the community may be able to provide additional information on past
floods to assist with the computer model validation. In this regard, a community
questionnaire was prepared and was distributed to approximately 3,000 properties located
within the catchment. A copy of the questionnaire is included in Appendix B. An online
version of the questionnaire was also hosted in Council9s Your Voice.
The questionnaire sought information from the community regarding whether they had
experienced flooding, the nature of flood behaviour, if roads and houses were inundated
and whether residents could identify any historic flood marks. A total of 45 questionnaire
responses were received. A summary of all questionnaire responses is provided in
Appendix B. The spatial distribution of questionnaire respondents is shown in Figure B1,
which is also enclosed in Appendix B.
The responses to the questionnaire indicate that:
The majority of respondents have lived in or around the catchment for at least 8 years.
Around 30% of respondents have experienced some form of inundation or disruption as
a result of flooding in the catchment. The spatial distribution of respondents that have
reported past flooding problems is shown in Figure B1 in Appendix B (refer red dots).
The reported impacts included:
•
Above floor inundation of home/business (3 respondents)
•
Flooding of garage (3 respondents)
•
Traffic disruptions (10 respondents)
• Inundation of front/back yards (7 respondents)
Respondents were able to provide descriptions of flood behaviour and/or provide
photos for the past floods:
•
July 2022 (9 respondents)
•
March 2022 (8 respondents)
•
March 2021 event (5 respondents)
• June 2016 (6 respondents)
Some respondents believe flooding in the catchment is exacerbated by:
•
Insufficient stormwater capacity (17 respondents)
•
Blockage of the culverts, bridges and/or stormwater inlets (15 respondents)
•
Insufficient creek capacity (6 respondents)
Several respondents also provided photographs showing past floods. A selection of these
photographs is provided in Plate 6 to Plate 8.
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