Thirroul And Bulli Just Got New Flood Maps For The First Time Since 2002. Here's What Changes For Buyers. — Week Ending 30 August 2026

The Take

Wollongong Council quietly formalised a new flood management plan for the Hewitts Creek catchment this month, and if you're looking at anything in Thirroul or Bulli near The Esplanade, Lachlan Street, Black Diamond Place or the old Hewitts Avenue pocket, this matters more than the price guide.

The plan replaces modelling that's been in place since 2002. For over two decades, insurers and council priced flood risk off numbers that didn't account for the bridge at the base of Bulli Pass, the McCauleys development, or a bridge measurement that turned out to be wrong by more than a third.

Owners in that catchment have spent years paying inflated premiums and getting knocked back on renovations because of a model most people on the ground knew was off. That model is finally gone. The new study covers 7.8 square kilometres from the escarpment down to Thirroul and Sandon Point beaches, and it's headed for the NSW Flood Data Portal - which means insurers, conveyancers and every due diligence report from here on prices off the new numbers, not the old ones.

Here's the part nobody's telling buyers: new modelling doesn't mean better news for every address. Some properties come out with a cleaner risk profile and a cheaper premium. Others, sitting somewhere the 2002 study underestimated, come out worse. You won't know which side of that line a specific property sits on by reading the listing or the standard flood certificate your solicitor pulls by default, because that document lags the new study by design.

If you're in contract or about to make an offer on anything in that catchment, get the flood position checked against the new plan before you sign, not after settlement when the insurance quote lands. And if you're a vendor in that pocket who's been sitting under punitive premiums for years, a favourable new number is a genuine selling point nobody else on your street can claim yet - most agents won't think to use it.

The Numbers

• NSW clearance rate: 57% (week ending 29 August) vs 73% a year ago - fourth straight week under 60%

• Illawarra median days on market: 29 days (year to June) vs 36 the year before - Cotality expects this to reverse as listings rise

• Hewitts Creek catchment: 7.8km² across Thirroul and Bulli reassessed for the first time since 2002

The One Action

If you're buying anything in the Hewitts Creek catchment - broadly Thirroul below the escarpment through to Bulli's Black Diamond Place pocket - request a flood report benchmarked against the new 2026 plan before you exchange, not the default certificate your solicitor pulls. It's a five-minute ask that can save you a five-figure insurance surprise, and if the news is bad, it's leverage the other side can't argue with.