--- title: "24151 – APN Flood Exposure Metric" url: https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/24151-apn-flood-exposure-metric/ date: 2026-01-16 modified: 2026-10-04 lang: en author: "" description: "APN Codex Node 2415124100 Series — Social Capital, Substrate BranchCertified APN Flood Exposure Metric Localities (N) 6,624 National Mean 92.06 Std Dev 25.73 Range 8.68–100.00 1What It Measures One of..." word_count: 570 --- # 24151 – APN Flood Exposure Metric APN Codex Node 2415124100 Series — Social Capital, Substrate BranchCertified ### APN Flood Exposure Metric Localities (N)6,624 National Mean92.06 Std Dev25.73 Range8.68–100.00 1What It Measures One of five Substrate components. Measures flood-hazard presence per locality — the greatest value across all available state flood-hazard flag layers, inverted to a national percentile rank (100 = no flood-hazard flag present, most resilient). **Source:** state/territory flood-hazard layers of varying quality — true 1% AEP hydraulic extents (VIC, ACT, WA), an evidence-based planning overlay (SA), a coarse statewide overlay (QLD), a sparse historical compilation (TAS), and a partial regulatory layer (NSW). 2Data & Coverage Notes Coverage confidence varies sharply by state — flagged, not gated **NSW:** only ~12 of ~129 LGAs (11% of population) have any flood data at all — effectively unmeasured for 89% of the state, including every LGA in the top 8 by population. **TAS:** a sparse 2008-vintage compilation, 35 polygons nationally. **NT:** genuine structural NIL — no statewide flood data exists; NT carries no 24151 row at all. Per policy, low-confidence localities are still scored (not NIL'd) with their confidence flagged, rather than silently implying more certainty than the source supports. **QLD reclassified low-confidence, 29 Jul 2026 — a genuine finding, not a routine flag.** An independent benchmark check against published Climate Council/Insurance Council of Australia data found QLD holds ~40% of Australia's at-risk flood properties nationally and the highest state-level "uninsurable by 2030" rate (6.5%) of any state — yet QLD's hit rate in this dataset (2.5%) was among the lowest of all built states. QLD's source is a coarse 2013 statewide overlay explicitly not intended for parcel-level use; the benchmark check turned that quality caveat into concrete evidence the coarseness likely **understates** QLD's true flood exposure. 3National Distribution N6,624 Mean92.06 Std Dev25.73 Min8.68 Max100.00 Distribution 24151 Score — All 6,624 Scored Localities Heavily concentrated at 100 (no flood-hazard flag present) — a direct consequence of the low hit rates documented above (0.1%–9.0% by state), not an indication that flood risk is rare nationally. 4Pillar Alignment **Alignment with the pillar.** Across the 6,624 localities scored on both, this component and APN Substrate™ (Climate Resilience Rating) (24150) have a correlation of **0.65**, on a scale where 1 means the two scores move together exactly and 0 means they are unrelated. The two are moderately aligned: a locality that scores high on this component tends to score above average on Substrate, with many exceptions. This component is one of the pillar’s five inputs, so part of that alignment is built into the pillar itself. A state and territory comparison is not shown for this component. The flood-hazard layers behind it are compiled separately by each jurisdiction and differ in coverage, and no Northern Territory localities are scored, so state averages would reflect differences between source layers rather than differences in exposure. 5Other Components The other four components of APN Substrate™ (Climate Resilience Rating) (24150). [Node 24152 →APN Bushfire Exposure MetricReads bushfire hazard from fire-weather climatology and historical fire incidence.](https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/24152-apn-bushfire-exposure-metric/) [Node 24153 →Catastrophe History IndexReads whether a recorded insured catastrophe event has touched the locality.](https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/24153-catastrophe-history-index/) [Node 24154 →Geological BaseReads earthquake hazard as design-level peak ground acceleration.](https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/series-24154/) [Node 24155 →The Green Floor (Eco)Reads the protective presence of carbon and conservation projects and protected land nearby.](https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/series-24155/) [Parent branch →24150 — APN Substrate™ (Climate Resilience Rating)](https://australianproperty.network/apn-codex/series-20000/series-24000/series-24100/series-24150/) 6Certification APN Codex Node 24151 — Certified, v0.2 - Flag-don't-gate coverage policy applied - QLD reclassified low-confidence via a cross-state benchmark check