Buried deep inside the Hawkesbury Council’s 129-page Draft 2025 Flood Plan is a proposal that could change the future of Windsor and the surrounding Macquarie towns in ways that few residents likely see coming. The recommendation, to raise the flood control level to the 1 in 200 AEP (Annual Exceedance Probability) event, plus a 0.5-meter freeboard, would push the flood planning level in Windsor to 19.3 meters - nearly two meters higher than the current benchmark.

At first glance, this technical-sounding adjustment might seem like a minor policy shift. But for tens of thousands of property owners across the region, the implications are nothing short of seismic. The flood planning level serves as the official marker that determines whether land is considered flood-prone, and it plays a crucial role in decisions about everything from home insurance to financing, resale value, and the permissibility of development. In simple terms, this recommendation could reclassify large portions of Windsor and other towns as too risky to build on, sending shockwaves through the property market.

For Windsor alone, this higher flood planning level would bring drastic changes. Thousands of homes and businesses, which currently sit just above the existing flood level, would now fall below the new mark, triggering a domino effect of economic and personal consequences.

Property values in these areas could plummet as buyers shy away from flood-prone land. Insurance companies, already hesitant to cover properties below the 1 in 100 AEP level, could withdraw further, leaving many homeowners without the safety net of flood insurance. Financing, too, would become a major hurdle. Banks have already been limiting loans for properties at risk of flooding, and an increase to the 1 in 200 level would make securing a mortgage even more difficult.

The implications don’t stop there. Under the new flood control level, property owners may face severe restrictions on what they can do with their land. Any sort of development - whether it’s building new homes, making improvements, or even repairing damage - would be subject to tighter controls. Floor levels for new buildings would need to be elevated to meet the new flood standards, and the process of getting approval for even minor changes could become bogged down in red tape. For many, this could mean the end of future development plans and a sharp reduction in the value of their investments.

The impact wouldn’t be limited to Windsor. The new flood planning level would affect a wide area, including most of the other Macquarie towns. While these places have long dealt with flood risks, the proposed changes would cast a much wider net, pulling in properties that were previously considered relatively safe from flooding. Ironically, the new measures would have little impact on the Hawkesbury Lowlands, where the 2020 flood policy changes already precluded almost all development. However, it is likely to impact resale value as buyers find it harder to obtain finance. But, for areas like Windsor and Richmond, the proposal represents a seismic economic and planning change.

What makes this situation even more troubling is how the proposed changes have been communicated - or rather, not communicated. Hidden in the depths of a lengthy technical document, these recommendations haven’t received the clear, public-facing explanation that such a significant change deserves. For a policy that could affect tens of thousands of people, critics argue that the council should have done much more to bring these issues into the spotlight. Instead, many residents who stand to lose the most may not even be aware that their property is on the verge of being reclassified.

The Draft 2025 Flood Plan has been placed on public exhibition, inviting comments from the community. However, the lack of widespread awareness about the proposal means that many people may not realise the scale and implications of the changes being proposed. The last day for the receipt of submissions is Monday 9 December 2024.

Council’s flood management strategy is built on the idea of safeguarding the community from future flood events, and the proposal to raise the flood planning level is presented as a necessary step in preparing for increasingly severe floods, compounded by climate change. The draft plan even mentions that the current flood planning levels don’t fully account for potential flood risks, particularly as the region faces growing uncertainties in predicting flood behavior. The inclusion of a 0.5-meter freeboard - a safety buffer added to the 1 in 200 AEP level - is designed to account for these uncertainties, including factors like storm surges, wind influences, and potential errors in flood modeling.

“Typically, in coastal locations a 0.5m freeboard above the 1% AEP is similar to the 0.5% AEP level. At Windsor the freeboard would need to be 1.2m to provide an Flood Planning Level at the 0.5% AEP level. With climate change 2030 1% AEP flood levels are already close to the historic 0.5% AEP. Given the extreme flood range, consideration should be given to using a flood planning level greater than the 1% AEP. The extreme flood range or the climate change risk (as discussed in Section 7.3) are enough in isolation to recommend consideration of a higher flood planning level than the 1% AEP,” the study conducted by engineering consultants, WMA Water said.

"Hawkesbury City Council’s current planning documents set the Flood Planning Level to the 1% AEP level without freeboard. The nature of the Hawkesbury-Nepean Valley means that the additional area affected by an increase in flood planning level is small. Based on the flood range and climate risk it is recommended that Council adopt the 0.5 % AEP (1 in 200 AEP) as the defined flood event and the 0.5 % AEP (1 in 200 AEP) plus 0.5m freeboard for the Flood Planning Level….Therefore, it is recommended that Councils planning documents be updated to reflect this. Consideration should be given to the inclusion of climate change in planning levels," it said.

You can see how the new proposed flood planning levels would impact your home here - New Draft Flood Plan HCC