# Extreme storm impact and recovery on a natural beach-foredune system: The June 2016 storm at Bengello Beach, southeastern Australia

## TL;DR

A 2016 storm severely eroded a beach and dune system in Australia, highlighting the importance of wide beaches and vegetated dunes in storm recovery.

## Contribution

The study quantifies erosion and recovery patterns after an extreme storm, emphasizing the role of natural dune systems in coastal resilience.

## Key findings

- Erosion volumes reached 97–108 m³/m in central and southern parts of the beach.
- A surf zone bar temporarily stored eroded sand seaward of the typical location.
- Recovery took nearly three years, with a narrower and less resilient foredune.

## Abstract

The June 2016 extratropical cyclone with anomalous ENE storm wave direction caused widespread beach-foredune erosion in southeastern Australia. At Bengello Beach, erosion volumes were 97–108 m3/m for the central and southern parts of the beach, while the northern end only lost 18 m3/m of sand. In the central and southern parts of the embayment, a surf zone bar formed 50–100 m further seaward than is typical for this beach and was a temporary store of sand eroded from the beach-foredune. A nearshore wave model showed substantial variability in wave power along the 10 m depth contour and explained the partial sheltering of the northern end of the embayment from storm impact. An embayment-wide time-series of airborne LiDAR further emphasised the alongshore variability in beach-foredune erosion. The wide beach and broad, double-crested, well-vegetated foredune along much of the embayment was pivotal in protecting the shoreline. In the centre and south of the beach, recovery took nearly three years and although complete by volume, the foredune was narrower and less resilient. The results emphasise the role of wide beaches and natural vegetated foredunes in buffering extreme storms and suggest foredune rehabilitation should be a key management priority for sustainable coasts.