John Xanthis, Wilson Inlet Restoration Group, Denmark Bulletin

Wilson Inlet opened on September 25 at 0.88 AHD in relatively ideal conditions with a north-easterly breeze, a declining swell, a good variation spring tidal range and a high pressure system.

A big crowd attended the opening.

It was decided that a 60m western opening would be best to service the middle gutter and Prawn Rock Channel which feeds into the cockle shell gutter in Poddy Shot Bay.

A channel was dug pointing to the north of Bird/Dog Island.

When doing so, patience is needed for low openings around 0.9 AHD to form a channel.

The next run-out day was also needed to ensure the main southern gutter behind the Nullaki to link the opening.

Unfortunately, water levels were low and late this year due to a dry winter with little river flow.

Excavating the channel through a high point of the sand bar to the ocean slowed the flow of the opening.

The sand bar was 30m further south from the cliffs than a normal year.

Low openings historically are a slow release of water compared to a 1.2m AHD opening in ideal conditions.

An 80m serviceable sand bar opening was however achieved.

It is hoped that more substantial rain will fall before Christmas to keep our jewel of the South Coast open.

A significant factor negatively impacting a successful and serviceable opening in winter is the damming of the surrounding catchment, especially relevant now in an ever-drying climate.

A declared inlet catchment area is urgently needed to monitor and ensure compliance of reasonable water usage.

There are hydrologists’ estimates of 20 per cent of the water being dammed upstream in the catchment before sand bar openings in an average year.

High water use farming practices, blue gums, droughts and declining rainfall puts Wilson Inlet at risk of not opening, if proactive steps are not urgently taken to address this issue.

This article appeared in the Denmark Bulletin, 10 October 2024.