We have reached the next stage of the Flood Risk Management Study & Plan (FRMSP) project and would like your input.

Our consultants have finished the updates required to the flood model to refine it based on the valuable submissions received during the 2024 community engagement, subsequent onsite inspections across the LGA, and updates in line with flood modelling industry progress and best practice as well as the required incorporation of updated climate change data and forecasting.

They have investigated, modelled and undertaken preliminary assessment of possible flood mitigation options across the LGA and we would like the community’s feedback on the results.

We held two public webinar presentations in late July providing an update on the Flood Risk Management Study and Plan. Within this presentation (which is available to view on the top right hand side of this web page) we shared the key flood mitigation infrastructure options which we are exploring. We are inviting residents, owners and businesses who have ideas, knowledge of the catchment or input they would like to share with us, to do so via email: floodriskmanagement@waverley.nsw.gov.au or in person at a one-to-one session with our team on the 5th or 6th of August (now finished).

Please ensure you have watched the webinar prior to submitting feedback. Submissions closed at midnight on Sunday 10th August 2025. Thank you

We have now progressed to the next crucial stage of the project. Our focus is currently on reviewing flood risk management and mitigation options. We are evaluating a range of potential strategies to manage and mitigate flood risk in the Waverley LGA:

Infrastructure Solutions: Our consultants have been exploring, modelling and assessing the infrastructure solutions we could undertake to reduce and alleviate flooding across the Waverley catchment.

Development Planning Controls: They have also been reviewing and updating the proposed flood planning areas and precinct maps based on the updated flood mapping. We will update these to ensure they accurately reflect (and protect future development from) the updated flood risk.

Targeted community consultation: As we delve deeper into specific flood risk management and mitigation options, we are conducting targeted community consultation in identified hotspot areas.

Following the valuable feedback received during the community consultation in June-July 2024, our consultant has integrated this input into the project and reviewed and updated the model outputs.

Key activities completed in this phase include:

Feedback integration: The consultant has reviewed all community consultation feedback and incorporated relevant insights into the project’s technical work, informed further by subsequent onsite meetings with residents across the Waverley catchment.

Model review and outputs: A comprehensive review and update of the flood model has been completed in line with flood modelling industry best practice and progress since the original study, including the required incorporation of updated climate change forecast data.

Updated flood mapping: Following the above updates, simulations have been re-run to produce updated flood maps. These maps will provide a clearer picture of expected flood extents and depths across the LGA.

Ground truthing inspections: To ensure the accuracy and reliability of the model and mapping the consultant team has conducted further on the ground inspections in key areas and verification of modelled flood extents against historical and recent rainfall events.

In addition to the progress made on the FRMSP project, we’ve undertaken a number of other actions in parallel to reduce the impact of flooding within the community:

• Condition assessment of 14.5km of Council’s stormwater network (16%) in the past 12 months to identify blockages and defects. The full network will be inspected and assessed by 2030,
• High impact blockages and defects identified have been cleared and/or rectified already,
• Resourcing needs have been identified and programmed to clear and rectify those remaining,
• Our operations team have attended a large number of reactive incidents prior to and during storms to clear stormwater inlets, unblock drains and fix drainage issues across the network to improve flow and prevent flooding in real time,
• We’ve undertaken minor stormwater capital improvement works across the LGA in problematic locations identified by residents to eliminate easily addressable flooding issues.

Building on the completion of the Waverley Local Government Area (LGA) Flood Study, which was adopted in 2021, Waverley Council commenced the next step in the NSW Governments Flood Risk Management Framework in early 2024 - a Flood Risk Management Study and Plan (FRMS&P) for the Waverley LGA .

The objective of this project is to refine the model across the LGA and explore and recommend flood mitigation options to reduce or alleviate detrimental impacts of flooding where possible.

This project has two parts.

The Flood Risk Management Study

To incorporate community knowledge of flooding and undertake ground testing onsite to further refine the Waverley LGA flood study, improving its accuracy and the confidence that the community has in the flood planning maps. To develop and assess flood risk mitigation measures to reduce or alleviate existing and future flood risks in our community.

The Flood Risk Management Plan

This part of the project focuses on recommending and prioritising flood risk mitigation measures, including documenting the decisions made to manage flood risks into the future. A list of recommended measures and their priority are detailed in the plan including how they would be implemented and who is responsible.

The study and plan are being prepared by independent flood consultant Kellogg Brown & Root Pty Ltd (KBR) and urban planning consultant GLN Planning Pty Ltd. With joint support and funding from NSW Department of Climate Change, Energy, the Environment and Water (DCCEEW) under their Floodplain Management Program.

This project is separate to previous recently completed projects including the Waverley LGA Flood Study 2021 and the amendment to the Waverley Development Control Plan 2022.

2017

• Waverley Council started work on the Flood Study involving community feedback.
• The study was completed in accordance with the NSW Floodplain Development Manual and NSW Flood Prone Land Policy.

2020

• Study released for public exhibition.

2021

• Waverley Council adopted the Waverley LGA Flood Study.
• Council developed proposed amendments to Waverley Council’s Development Control Plan.

2022

• Proposed changes to Waverley Council’s Development Control Plan (DCP) exhibited.
• Low, medium and high-risk areas were identified.

2024

• Council engaged a consultant to start the Flood Flood Risk Management Study & Plan in February 2024.
• DCP amendment adopted in March 2024

For more information on flood management see the flood management pages on Council's website.

Definition of a flood

Flooding results from relatively high stream flow that overtops the natural or artificial banks in any part of a stream, river, estuary, lake or dam, and/or local overland flowpaths associated with major drainage, and/or oceanic inundation resulting from super-elevated ocean levels.

What is mainstream flooding?

Mainstream flooding is water that overtops the natural or artificial banks in any part of a stream, river, estuary, lake or dam..

What is overland flooding?

Local overland flooding is inundation by local run-off on its way to a waterway, rather than overbank flow from a waterway. Overland flooding typically occurs during rainfall events where drainage systems reach capacity and excess water flows over land.

What is stormwater?

When rainwater comes into contact with surfaces such as roofs, paved areas such as roads, gardens, and other open spaces, it becomes stormwater.

Refer to FAQ in Document Library for more information

The Flood Risk Management Study and Plan will have three stages of consultation during the delivery of the project.

• June - July 2024: Complete

• July - August 2025: Flood mitigation consultation.

• Dates to be scheduled: Public exhibition of the draft Flood Risk Management Study and Plan.

Stage 1 - Consultation

From June 11 to July 15, 2024 Waverley Council held a community consultation for part one of the Flood Risk Management Study and Plan.

Residents and property owners were asked to supply information, images and video relating to flooding they had experienced, either at their home or in other areas of Waverley. It was organised LGA-wide, focussing on the collection of data via Council’s Have Your Say (HYS) website.

Eighty-two submissions were received via the website, as well as 51 emails to the project team. Ten people attended Have Your Say face-to-face pop-ups across the LGA.

The Community Consultation Report can be found in the document library on this webpage.