The 290-km Whanganui River is the second longest in the North Island, after the Waikato. Rising on the north-west flank of Mt Tongariro, it reaches the Tasman Sea at Whanganui. From its source, the river flows north-west for 60 km, then turns sharply south at Taumarunui.
Its main tributaries are the Ōngarue from the north, the Ōhura and Tāngarākau from the west, and the Manganuiōteao from the east. The latter rises on the west side of Ruapehu and flows due west. Joined by the Ruatītī, it meets the Whanganui not far above Pipiriki.
According to Māori tradition, in ancient times three mountains, Ruapehu, Tongariro and Taranaki, lived together in the centre of the North Island. One day Taranaki attempted to carry off Pīhanga, the wife of Tongariro. In the ensuing battle Taranaki was defeated and escaped down to Whanganui. As he fled, he carved out the deep furrow of the river.
For most of its course, the Whanganui River course is deeply entrenched in sandstone and mudstone, and the runoff makes it very muddy.
The river’s most spectacular scenery is in its middle reaches, between Whakahoro and Pipiriki, where it passes through a series of narrow gorges amidst one of the North Island’s largest areas of unmodified lowland forest, much of it part of Whanganui National Park. The river has 239 named rapids, but a gentle gradient. Lacking falls, it is navigable upstream as far as Taumarunui.
There were major floods in 1904, 1940, 1958, 1965, 1990 and 1998, and the lowest parts of Whanganui city were flooded in 1904 and 1940. Since 1972 some of the Whanganui’s headwaters have been diverted to the Waikato River by the Tongariro power scheme.
The river near Whanganui city is important for rowing, and jet boating and canoeing are popular upstream.
There are just four bridges across the river downstream of Taumarunui – all in Whanganui city.
People of the river
The river is the home of the Whanganui iwi (tribes), also known as Te Āti Haunui-a-Pāpārangi, a confederation of three ancestral groups: Hinengākau of the upper river, Tama Ūpoko of the middle reaches and Tūpoho of the lower Whanganui.
The river is of huge importance to the iwi: it is their ancestral river, their arterial highway, and a source of physical and spiritual sustenance. Although few Whanganui Māori now live on the river, it remains a focal point. In 2017 the Whanganui River was recognised in New Zealand law as a living being with legal personhood.
Bridge to somewhere, then nowhere
Surrounded by forest, the 38-metre-high ‘bridge to nowhere’ is a remnant of a failed attempt to farm the remote Mangapūrua Valley. After the First World War, a government scheme settled soldiers on the largely infertile land, at the end of a long, rough road from Raetihi. A wooden swing bridge over the Mangapūrua stream connected road and settlement to a landing on the nearby Whanganui River. A concrete bridge replaced it in 1936 – but just six years later the last settlers abandoned their farms. Today the structure is a drawcard for visitors to the national park.
There was inter-tribal fighting on the Whanganui in the early 19th century and the 1860s. In 1864, lower river Māori fought off upriver Pai Mārire converts at Moutoa Island, 61 km north of Whanganui town.
Alexander Hatrick ran a regular steamer service between Whanganui and Pipiriki from 1892, and it was extended to Taumarunui in 1903. Improved roads undercut the service, and it ceased in 1958.
From the 1930s many Māori found work in towns. Today the total river population is less than 1,000, in settlements along the lower river road, which opened in 1934.
Today the kayaking trip down the river from Taumarunui to Pipiriki is popular.