Dozens of notches 1.5m-2m wide and 1m-2m deep were cut at 10m to 15m intervals between the St Kilda Surf Life Saving Club and Lawyers Head in 2018, to encourage growth of the dunes and reduce the impact of erosion.
Since then, they have helped to shift several hundred cubic metres of sand into the dune, Dunedin City Council coastal specialist Tom Simons-Smith said.
''They are designed so that sand is blown to the back of the dunes in strong west to southwest winds, allowing the dunes to grow over time and become more resilient to erosion caused by storms and rising seas.''
He said the work was associated with research conducted at the university's geography department since 2016.
It had led to a much better understanding of the most effective shapes and spacings of notches, and had received considerable national attention for its inventive and natural approach to coastal management.
The first annual tidy-up was carried out yesterday, to keep them working well, he said.
''Vegetation will be removed from the notches with an excavator and the shape of some notches will also be changed so that more sand can be blown to the back of the dunes.''
