The Taramakau River is a river of the West Coast Region of the South Island of New Zealand. It rises in the Southern Alps / Kā Tiritiri o te Moana near Harper Pass, due east of Hokitika, and runs westward for into the Tasman Sea south of Greymouth. The Taramakau River forms the administrative boundary between the Westland District to the south and the Grey District to the north. Several small rivers are tributaries of the Taramakau. The largest of upper tributaries are the Otehake River and the Ōtira River. The valley of the Ōtira forms the western approach to Arthur's Pass. The Taipo River is a major tributary joining the Taramakau from the south, downstream of Inchbonnie. Statutory acknowledgement The South Island iwi Ngāi Tahu have manawhenua or tribal authority over the Taramakau River, acknowledged under s56 of the Ngāi Tahu Claims Settlement Act 1998. The Taramakau was a traditional route of travel across the Southern Alps, providing access to Nōti Taramakau (Harper Pass), one of the lowest and most accessible passes through the mountainous terrain. The river has also been a source of the highly prized stone pounamu. Taramakau Bridge at Kumara Junction The Taramakau River posed significant difficulties and dangers for early travellers on the West Coast. The explorer Henry Whitcombe drowned crossing the river on 6 May 1863. There are two memorials to Whitcombe; one on the river's left bank at the (road-)rail bridge, and he is one of the four men commemorated by the Westland Explorers' Monument in Hokitika Cemetery. Before a bridge was built near the coast, a cable way operated across the river, carrying a tram car.On 18 December 1893, the railway line from Hokitika to Greymouth opened, including a long single-lane road and rail bridge across the Taramakau River near Kumara Junction. By 2016, this bridge was New Zealand's last remaining road and rail bridge. There were 25 crashes on the bridge in the 10 years to June 2015, including one fatality in 2012. The one-lane bridge also caused traffic congestion on State Highway 6, because vehicles had to queue before crossing. Work on a new road bridge commenced in 2016 and was completed at a cost of $25 million. The new bridge was opened on 22 July 2018. The old bridge continued in service as a rail-only bridge. Stopbanks at Inchbonnie The Taramakau River crosses the Alpine Fault at Inchbonnie. At