Floodplain Risk Management
Council is required to periodically review and update flood studies to ensure they reflect current best practice and provide accurate information on flood behaviour, risks, and impacts. These updates strengthen community safety, protect public and private assets, and support informed land use planning.
To meet this requirement, the City of Ryde commissioned WMAwater to undertake a Flood Harmonisation Study across all 14 catchments in the LGA. This project updated the previous Flood Studies (FS) and Floodplain Risk Management Studies and Plans (FRMS&P), in line with the NSW Flood Risk Management Manual (2023) and the Australian Rainfall and Runoff (ARR) Guidelines (2019). By harmonising the studies, Council has established a single, consistent and reliable source of flood information to better guide development and flood risk management across the City of Ryde.
A comprehensive Flood Study, which utilised historical data, climate change forecasts, and flood simulation models to identify flood risk and the potential extent, level and velocity of floodwaters in the Ryde LGA, was completed to help guide the Floodplain Risk Management Study and Plan.
The study provides updated flood behaviour data and mapping for the entire LGA, resulting in revised flood maps and flood mitigation plan.
Flood Study
What is a Flood Study?
A Flood Study is a comprehensive technical investigation that analyses flood behaviour and risk within a catchment using advanced computer modelling to simulate flooding conditions. It defines flood depths, velocities, and hazard, using advanced computer modelling to form the technical foundation for a robust Floodplain Risk Management Plan.
View Adopted Flood Study 2025
- Flood Study Report(PDF, 6MB)
- Appendix A Terminology and Glossary(PDF, 193KB)
- Appendix B November 1984 Flood Calibration Results and Photos(PDF, 1016KB)
- Appendix C February 1990 Flood Calibration Results and Photos(PDF, 99KB)
- Appendix D February 2010 Flood Calibration Results and Photos(PDF, 4MB)
- Appendix E November 2018 Flood Calibration Photos(PDF, 748KB)
- Appendix F Design Flood Event Mapping(PDF, 97MB)
- Appendix G Design Flood Event Reporting Tables(PDF, 321KB)
- Appendix H Sensitivity Results Mapping(PDF, 28MB)
- Appendix I Community Consultation Report(PDF, 2MB)
- Attachment A: ARR Datahub Data(PDF, 349KB)
- FIGURES(PDF, 130MB)
Key Flood Maps
Flood Risk Management Study and Plan
What is a Flood Risk Management Study & Plan?
The Floodplain Risk Management Study and Plan (FRMS&P) builds on the completed Flood Study to identify, assess, and prioritise measures to reduce flood risk and its impacts across the study area. It outlines how Council and property owners can manage and mitigate flood risk now and into the future.
The FRMS&P is prepared in accordance with the NSW Government’s Flood Prone Land Policy and Floodplain Development Manual (2023), which promote a balanced, merit-based approach to achieving sustainable development on the floodplain.
View Adopted Flood Risk Management Study and Plan 2025
Properties Subject to Flood-Related Development Conditions
The Flood Study has identified Flood Planning Areas (FPAs). Under the Study endorsed by Council in 2025, properties located within a Flood Planning Area are classified as flood control lots and are subject to specific development conditions designed to reduce flood risk.
Even if there is no historical evidence of flooding at your property, new building works must ensure that floor levels are constructed above the designated flood level to minimise potential flood damage. These properties are identified as flood control lots on Section 10.7 Planning Certificates, which are issued during property sales.
Flood planning area
A Flood Planning Area (FPA) is land identified as being potentially affected by a 1% Annual Exceedance Probability (AEP) flood, plus a safety freeboard, where flood-related development controls apply to manage risk to people and property.
Previous Flood Studies & Flood Risk Management Study and Plans
The previous Flood Study and Flood Risk Management Study and Plan can be accessed via the links below; however, these have been superseded by the updates completed as part of the Flood Harmonisation Study.
Is your property flood affected?
For further information on whether your property may be subject to flood related development controls, contact Customer Service on 9952 8222.