Petition to Review and Remove Unjustified PMF Mapping in the 2026 Sutherland Shire Overland Flow Flood Study

We, the undersigned residents and property owners of Sutherland Shire, call on Sutherland Shire Council and the NSW Government to urgently review the proposed Probable Maximum Flood (PMF) mapping in the 2026 Draft Sutherland Shire Overland Flow Flood Study and remove PMF classifications where they are not supported by a meaningful or credible flood risk at the affected property.

We recognise that flood risk management and emergency planning are important. However, the PMF represents an extremely rare and theoretical extreme flood scenario and should not result in properties being treated as meaningfully flood-affected where the available evidence does not support that conclusion.

We are particularly concerned about properties that:

1. are located on elevated or hillside land;
2. have no known history of flooding or overland water entering the property;
3. are physically separated from recognised drainage channels or flood paths;
4. have site topography that appears inconsistent with the mapped PMF extent; or
5. have been included in the PMF mapping primarily because of broad modelling assumptions rather than demonstrated property-level flood behaviour. 

There are examples across the Sutherland Shire where properties located on elevated ground or areas with no known history of flooding appear within the proposed PMF extent. This raises legitimate questions about whether the property-level mapping accurately reflects the actual topography, drainage pathways and likely movement of water during an extreme event.

The inclusion of a property within flood-related mapping can also create significant uncertainty for property owners. Residents are concerned that the mapping may affect perceptions of their property, future development opportunities, insurance considerations, lending and the marketability and value of their homes.

Council has stated that the 2026 Draft Study is intended to provide accurate information to support responsible planning and that community feedback will be considered before the Study is finalised. Council has also stated that the PMF is primarily used to understand the maximum extent of an extremely rare event and support emergency planning.

We therefore call on Sutherland Shire Council and the NSW Government to:

1. Undertake a property-specific technical review of properties included within the PMF extent where residents can demonstrate that the mapped extent appears inconsistent with the property's actual topography, drainage characteristics or historical flood experience.
2. Remove or amend PMF mapping where appropriate where technical evidence demonstrates that a property should not reasonably be identified as flood affected.
3. Provide greater transparency regarding the modelling assumptions that have resulted in individual properties being included within the PMF extent, including relevant ground levels, flow paths, hydraulic modelling assumptions and mapping methodology.
4. Consider actual local evidence, including historical flood records, photographs, survey information, site levels, drainage infrastructure, local knowledge and independent engineering evidence when assessing disputed properties.
5. Avoid treating PMF identification as equivalent to a demonstrated or frequent flood risk. The public should be clearly informed that PMF is an extreme-event planning scenario and does not necessarily mean that a property is expected to experience flooding under ordinary or frequently occurring rainfall events.
6. Provide affected property owners with a meaningful mechanism to challenge property-level mapping and have their individual circumstances considered before the final Study is adopted.
7. Assess the broader consequences of inaccurate or overly broad PMF mapping, including potential impacts on property owners' ability to develop, renovate, sell or insure their properties.

Ensure that the final flood mapping is proportionate, evidence-based and technically defensible, while maintaining appropriate emergency planning for genuinely flood-prone areas.

We support responsible flood management and recognise the importance of planning for extreme weather events.

However, responsible flood management should also mean ensuring that individual properties are not unnecessarily classified as flood affected when the available evidence does not support that conclusion.

We therefore ask Sutherland Shire Council and the NSW Government to review disputed PMF classifications and correct the mapping where appropriate before the 2026 Sutherland Shire Overland Flow Flood Study is finalised and adopted.