GRC Hydro | Flood Engineering Specialists in Sydney, Australia

The North Sydney LGA Floodplain Risk Management Study and Plan Questionnaire

Have Your Say on
Flooding in Your Area



We need your knowledge on flooding in your area

On behalf of North Sydney Council, GRC Hydro are undertaking the North Sydney Local Government Area (LGA) Floodplain Risk Management Study & Plan. We would like to hear your experiences of flooding to better understand how flooding occurs in your area and what measures may improve the current flood situation.

This study and plan will identify and recommend appropriate actions to manage flooding in your LGA. This study will be used by Council to manage flood risks in your area.



What is the Floodplain Risk Management Program?

The Floodplain Risk Management Program, managed by the NSW Government, helps Councils make informed decisions about managing flood risk, implementing management plans to reduce flood risk and to provide essential information to the SES to deal with flood emergencies.

This program consists of five stages and the current study will undertake the third and fourth stages of this process; Floodplain Risk Management Study and Floodplain Risk Management Plan. This follows on from the flood study completed by Council in 2017.


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What is Flooding?


Flooding is often associated with inundation from large rivers; however, there are many different flood mechanisms that can cause inundation. The North Sydney LGA is primarily affected by two types of flooding; overland flow flooding and creek flooding.

Overland Flow
Flooding

Overland flow flooding is caused from rainfall runoff generated from impervious surfaces.


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Creek
Flooding

Creek flooding occurs when runoff from streets and drains flows into waterways causing them to rise and inundate areas that are usually dry


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What is a floodplain risk management study and plan?


A Floodplain Risk Management Study and Plan draws on the results of a Flood Study to identify, assess and compare various flood risk management options. It provides information and tools to assess the flood impacts of different management options and provides a plan for the implementation of the preferred options.

A FRMS&P draws on the results of the flood study to identify, assess and compare various flood risk management options. These options are aimed at improving the existing flood situation in the LGA. The FRMS&P provides information and tools to allow considered assessment of flood impacts of management options and provides a strategic plan for their implementation. Management options are typically categorised as property modification measures, response modification measures and flood modification measures.



What is a FRMS&P used for?

A Floodplain Risk Management Study and Plan provides key information for Council, the SES and the community for effectively managing and mitigating flood risk.

For Council, FRMS&P’s are a planning tool for future development in the LGA and implementing flood mitigation measures for existing development areas. Examples of applications for Council include:
  • Identification and assessment of floodplain risk management measures for existing development areas aimed at reducing social, environmental and economic loss of flooding on development and the community; and
  • Examination of Council’s local flood risk management policies, strategies and planning instruments.


Information from the FRMS&P will assist the SES in its evacuation and logistics planning. The outcomes of the study will provide the SES with:
  • a clear description of flood behaviour in the study area for a full range of flood events;
  • a description of flood warning times for the LGA; and
  • identification of critical evacuation issues in the LGA such as locations where road access is cut and the warning time before road access is cut.




The Study Area


The North Sydney Local Government Area covers an 11 square kilometre area with a topographic ridge running east to west sloping down toward Sydney Harbour to the south and Middle Harbour in the north. The topography creates a large number of steep catchments flowing generally north or south. The study area is shown in the map below, which shows the LGA boundary in purple along with suburbs and major roads.


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Why your feedback is important

GRC Hydro will be identifying areas that are significantly flood affected and assessing flood modification measures to relieve the flood risk at these locations. This involves using computer models developed in the North Sydney LGA Flood Study to assess flood mitigation measures. Community input and knowledge of measures that might mitigate flooding in the LGA is invaluable to this study.



How you can help us

Your feedback is important in helping us get a complete picture of the community’s knowledge of flood behaviour and mitigation in your LGA. Please complete the questionnaire linked below to help Council better understand your experiences with flooding.



Who can you contact for more information?

If you have any further questions regarding the study or any further flood information/photos please attach them in the questionnaire or contact the following representatives.



Nathan Cheah
Associate, GRC Hydro
[email protected]
(02) 9030 0342


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Jim Moore
Engineering Project Manager, North Sydney Council
[email protected]
(02) 9936 8100


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Please help us to better understand flooding in your area by completing the questionnaire below.



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