South Beach Whanganui: Swimming, Water Quality, Surf and Getting There

Whanganui District Council describes it as wild and untamed: as soon as the tide goes out, it becomes a 20-kilometre stretch of sand. There is a parking area and a short walk to the beach, but for full access along the sand the council advises a four-wheel drive.

Discover Whanganui notes off-road trails up and down the coast and several peaks along the beach that offer views and climbing.

Much of the land behind the beach is administered by Whanganui District Council under the Harbour Boards Dry Land Endowment Revesting Act 1991. A 2004 historical survey of South Beach by the Department of Conservation records that the iwi of the Whanganui River trace their occupation of this coast back many centuries.

The survey describes a traditional fishing village on the South Spit near the river mouth, shell middens, including pipi, and stone-working sites near Kaitoke Lake and the stream. Middens stay hidden until the dunes move, so erosion can still uncover old middens and other remains, so leave anything you find where it is.

The coast was reshaped by work on the river entrance. According to the same survey, work on the South Mole at the end of the South Spit began in 1909, and by 1911 it was 3,200 feet long. The moles were later raised from half-tide level to above high tide.

Part of the land now occupied by the airport was once lagoon country, and the Wanganui Aero Club first developed the airfield in 1931. Second World War pillboxes were also built along this coast: one has been moved from its original position by foreshore erosion, and others may be hidden by shifting sand or scrub.

Today LAWA lists swimming, surfing and fishing at South Beach, and the council advises a four-wheel drive for full access along the sand. Discover Whanganui warns that the waves here are hollow and powerful and suited to intermediate and expert surfers only.

Across 151 tests between November 2019 and April 2025, 93% were suitable for swimming. A Fair grade means the water is usually fine for swimming but is more likely to be affected after rain, when runoff reaches the sea from the river and land.

Check the latest result on LAWA before you swim, and stay out of the water for at least 48 hours after heavy rain.

Horizons goes further and asks people to stay out of the water if it has rained heavily within the last 72 hours. The council does not close swim spots when a result is unsuitable, so the decision to swim rests with you.

South Beach is not patrolled. Both LAWA and Whanganui District Council say to watch the tides at all times, and the council asks visitors to take care at all times.

The surf is powerful, so swim with someone else and stay within your depth. If you would rather swim between the flags, Castlecliff Beach on the other side of the river and Kai Iwi Beach to the north are patrolled by lifeguards over summer.