Oriental Bay’s biannual sand shift explained

Well. Oriental Bay is an artificial beach maintained for the community by Wellington City Council.

In 2004, we purchased 22,000 tonnes of sand from the Golden Bay area in Nelson to enlarge and enhance both Freyberg and Oriental Bay beaches. The beach's sand area is now four times larger than before, and the Freyberg Beach grass area is twice as large as it once was.

Throughout the year, wind and wave action moves sand on the beach from east to west, with sand building up at the western end of the beach (near Freyberg) where it is held by the headland. If too much sand builds up at the headland, the holding area will overtop and the sand will be lost out into the harbour.

To maintain the size and shape of the beach, we undertake a sand shift twice a year. On behalf of the Council, Dixon and Dunlop relocate the built-up sand from the western end to the eastern end of the beach (near the Band Rotunda). This opportunity is also used to re-shape and tidy the sand along the shore.

Council’s Marine and Coastal Project Manager Joel De Boer says while reefs were built to reduce the amount of sand shifting, the sand needs to be topped up every 10-12 years. Additional sand was last added in winter 2015, when 1,000 cubic metres of new sand was shipped up from a quarry in Dunedin.

Joel says the sand was made from weathered and crushed granite, with the grain size carefully considered to ensure minimum sand loss from wind and sea currents.

Each year, an average of 1,900m3 (or 950 m3 biannually) of sand is moved at Oriental Bay beach. The sand is shifted by truck and pushed into place by a digger. One truckload is about 12m3, or 18 tonnes.

As heavy machinery does the redistribution work, the Oriental Bay and Freyberg beaches are closed during the sand shift operations to ensure public safety. The sand shift generally takes about three days to complete.

Joel says Oriental Bay typically experience 30 significant weather events a year, which contributes to the sand migration. The sand shifts occur in May and October each year.

And so that is the story of Oriental Bay’s biannual sand shift, and how we keep the beach looking tip top for Wellingtonians and visitors to enjoy.

Want to find out more about Oriental Bay? Check out our throwback Thursday history article.