The Karamea River is a river of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. It is located in the

Tasman Tasman most often refers to Abel Tasman (1603–1659), Dutch explorer. Tasman may also refer to: Animals and plants * Tasman booby * Tasman flax-lily * Tasman parakeet (disambiguation) * Tasman starling * Tasman whale People * Tasman (name), ...

and

West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...

Regions of the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

. The river rises within

Kahurangi National Park Kahurangi National Park in the northwest of the South Island of New Zealand is the second largest of the thirteen national parks of New Zealand. It was gazetted in 1996 and covers , ranging to near Golden Bay in the north. Much of what was the ...

in the Matiri Range of the Southern Alps. The river rises to the east of Mount Allen, meandering west briefly before turning north. After some 25 kilometres it again turns west, to enter a series of small lakes where its waters are joined by those of the Roaring Lion River. From here the river continues west through steep-sided valleys before leaving the national park and reaching its floodplain 10 kilometres from the coast of the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...

. The river passes the small settlements of

Umere Umere is a town in the Karamea area of New Zealand. Umere is a farming community on the north side of the Karamea River, upriver from the main Karamea township. Name The settlement was originally named Land of Promise, in contrast with the slig ...

and

Arapito Arapito is a town in the Karamea area of New Zealand. Arapito is a farming community on the south side of the Karamea River, and upriver from the main Karamea township. The settlement was originally named Promised Land; it was changed to Arapito ...

before reaching the

Ōtūmahana Estuary Ōtūmahana Estuary, also known as the Karamea Estuary, is a tidal estuary in the Buller District of the West Coast Region of New Zealand. It is located at the mouth of the Karamea River and also receives the outflow of Ōtūmahana creek (also ...

and the

close to the township of

Karamea Karamea is a town on the West Coast of the South Island of New Zealand. It is the northernmost settlement of any real size on the West Coast, and is located northeast by road from Westport. Apart from a narrow coastal strip, the town of Karam ...

Flood risk

There is a history of flooding from the Karamea River. In 1899, a large flood swept away a new bridge across the river and caused damage to settlers homes, farms and crops. Another major flood caused serious damage in January 1915, inundating the main street and the majority of houses. The Murchison earthquake on 17 June 1929 led to debris blocking the existing mouth of the Karamea River, and a new outlet to the sea formed from the Ōtūmahana lagoon around to the south of the existing outlet. Deposits of silt raised the level of the river bed and led to a greatly increased risk of flooding in the townships of Karamea and Market Cross. On 30 December 1929 there was heavy damage in Karamea and Arapito from a sudden flood attributed to the breach of a dam created during the earthquake. In April 1931, floodwaters entered most of the homes around Market Cross, and some in the Karamea township. In August 1931, the setllers were given access to relief funding from the West Coast Earthquake Relief Fund for the damage caused by these floods. Over the next few years, stop banks and training walls were constructed on the north side of the river to help mitigate the flood risk to the town. In May 1936 the Karamea School Committee notified the Education Board of their concerns about the damage caused by repeated flooding of the school. Relocation to a new site was proposed. In October 1936 there was a further major flood that entered 40 houses in Karamea and Market Cross. In September 1937, a large flood led to the river breaking through to the sea at the location of the old river mouth, cutting a new channel that greatly reduced the flood risk to the town and enabled the entry of vessels at high tide. Further river protection works were installed between 1938 and 1940, and these successfully defended the township during a heavy flood in the river in February 1940. Survey records since 1912 indicate that there have been either single or double openings to the sea from the Ōtūmahana Estuary, and that these openings have migrated over of shoreline since records began. Between 2008 and 2010, the two openings merged at a location giving a direct exit to the sea for the Karamea River. From December 2010, the combined opening migrated south. Between 2013 and 2015, the channel moved further south by over . In 2016, the channel was south of the most direct route from the river to the sea. This new location increases the risk of flooding in some areas of Karamea. A report to the West Coast Regional Council in 2016 recommended mechanical excavation of a breach channel to allow the next major flood to cut a new direct route to the sea, and mitigate the flood risk.

References

Rivers of the West Coast, New Zealand Buller District Kahurangi National Park Rivers of New Zealand Karamea {{WestCoastNZ-river-stub

Flood risk

See also

References