Flood Risk in Marion, SA: 2026 Assessment

Marion, South Australia· UNKNOWN
Marion faces a moderate risk of flooding, primarily from heavy rainfall events and stormwater runoff. The Patawalonga River and other local creeks can contribute to localized flooding.Updated 22 Mar 2026

Flood Risk Score

4.5/10

Marion faces a moderate risk of flooding, primarily from heavy rainfall events and stormwater runoff. The Patawalonga River and other local creeks can contribute to localized flooding.

Key Facts

Flood Risk
Marion faces a moderate risk of flooding, primarily from heavy rainfall events and stormwater runoff. The Patawalonga River and other local creeks can contribute to localized flooding.
Trend
increasing
Suburb
Marion, SA
Overall Risk
Medium
Postcode
5043
Highest high-risk exposure
11.1% of land (surface flood)

Flood Risk Analysis

Marion, located in South Australia, has a notable flood risk profile based on available data including proximity to waterways, elevation, and historical flood events. The Bureau of Meteorology (BOM) maintains river height and flood warning data for catchments across South Australia.

Historical flood events have impacted properties near the Patawalonga River. The council has implemented some flood mitigation measures, but further upgrades are needed.

Marion faces a moderate risk of flooding, primarily from heavy rainfall events and stormwater runoff. The Patawalonga River and other local creeks can contribute to localized flooding.

For a comprehensive property-specific flood assessment including address-level elevation data, flood overlay mapping, and insurance cost estimates, use the ClimateNest full analysis tool. General suburb data cannot replace a site-specific evaluation.

Marion sits within ClimateNest's suburb-level hazard model for flood risk. 2.3% of the suburb's land area is mapped in high-risk flood zones and 81.9% in moderate-risk zones, based on the national hazard overlay. Exposure at this scale varies street by street, which is why an address-level check matters before you buy or insure a specific property in Marion.

Marion (postcode 5043) is tracked in ClimateNest's suburb hazard model, which maps the share of the suburb's land exposed to each hazard at high and moderate levels. The suburb's highest high-risk exposures are surface flood (11.1% of land in high-risk zones), bushfire (6.1% of land in high-risk zones), coastal inundation (3.7% of land in high-risk zones). Exposure is not uniform across Marion — individual properties can sit well above or below these averages, so an address-level check is recommended before buying, selling or insuring.

Local Hazard Evidence

Nearest WaterwayPatawalonga River
Elevation Range5-30 meters
Flood Zone ClassificationAreas near the Patawalonga River and local creeks are prone to flooding.

Historical Events

2020
Minor

Heavy rainfall caused localized flooding in low-lying areas of Marion.

Adaptation & Mitigation Actions

Upgrade Stormwater Infrastructure

Near-term

Invest in upgrading stormwater drainage systems to handle increased rainfall intensity and reduce the risk of flooding.

Est. cost: High

Increase Green Spaces

Immediate

Plant more trees and create green spaces to reduce the urban heat island effect and provide shade during heatwaves.

Est. cost: Medium

Implement Coastal Protection Measures

Long-term

Construct seawalls and implement other coastal protection measures to mitigate the impacts of sea level rise and coastal erosion.

Est. cost: Very High

Develop a Heat Action Plan

Immediate

Create a heat action plan to protect vulnerable populations during heatwaves, including establishing cooling centers and providing public health advice.

Est. cost: Low

Council & Emergency Services

City of Marion
Emergency Services

Data last updated: 22 March 2026

Explore Marion Risk Reports

Frequently Asked Questions

Is Marion at risk of flooding?

Based on available data, Marion has a notable flood risk profile. Flood risk varies by address — check your specific property for precise flood zone mapping and elevation data with ClimateNest.

What flood insurance costs can I expect in Marion?

Insurance costs for flood cover in Marion depend on the property's flood zone classification, elevation, and proximity to waterways. ClimateNest provides address-level insurance cost estimates based on your property's specific hazard exposure.

Does flood risk affect property values in Marion?

Yes, flood risk can affect property values in Marion. Properties in mapped flood zones may experience lower buyer demand, reduced valuations, and higher insurance costs. Lenders increasingly assess flood exposure as part of mortgage risk evaluation.

How does elevation affect flood risk in Marion?

Elevation is a critical factor in flood risk. Properties at higher elevations within Marion typically have lower flood exposure than those near waterways or in low-lying areas. Address-level elevation data combined with BOM flood mapping provides the most accurate picture.

What share of Marion is exposed to high surface flood risk?

ClimateNest's hazard overlay maps 11.1% of Marion in high-risk zones for surface flood, with a further 64.5% in moderate-risk zones. Suburb-level exposure is not uniform — individual properties can differ from these averages, so an address-level check is recommended.

Is Marion Safe from Climate Risk?

Enter your address below for an instant climate risk assessment for Marion, South Australia, covering flood, bushfire, sea level rise and more.

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What A$69 could save you from

$7.2B
2022 insured disaster losses*
$300B+
climate risk to property by 2050*
30-120%
insurance premium increases in high-risk areas*

*Industry sources: ICA, APRA, RBA

Full report from A$69 · Australian addresses only · 8 hazard scores · Insurance trajectory · 2030 & 2050 projections