Ikamatua is a small village on the West Coast of the South Island

South Island

The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...

 in New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

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It is located on the State Highway 7

New Zealand State Highway 7

State Highway 7 is a major New Zealand State Highway. One of the eight national highways, it crosses the Southern Alps to link the West Coast Region with Canterbury and to form a link between the South Island's two longest highways, State Highway 1 and State Highway 6...

 inland route, 50 km north of Greymouth

Greymouth

Greymouth is the largest town in the West Coast region in the South Island of New Zealand, and the seat of the Grey District Council. The population of the whole Grey District is , which accounts for % of the West Coast's inhabitants...

 and 28 km south of Reefton. It has a population of under 200.

In 1946, 4 km north of Ikamatua, the floating Grey River

Grey River

The Grey River / Māwheranui is located in the northwest of the South Island of New Zealand. It rises in Lake Christabel, one of numerous small lakes on the western side of the Southern Alps,12 kilometres southwest of the Lewis Pass, and runs westward for 120 kilometres before draining into the...

 gold dredge dug its way across State Highway 7, and the main Greymouth to Westport

Westport, New Zealand

-Economy:Economic activity is based around fishing, coal mining and dairy farming. Historically, gold mining was a major industry, and coal mining was much more extensive than today . However, the region still is home to New Zealand's largest opencast mining operation in Stockton...

railway link, to move into its new mining area in the Blackwater Valley.
This was the first and only time that such an event has occurred in New Zealand.