The Ngakawau River is a river of the West Coast Region of 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...

's 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...

. It flows generally northwest, reaching the Tasman Sea

Tasman Sea

The Tasman Sea is the large body of water between Australia and New Zealand, approximately across. It extends 2,800 km from north to south. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European...

 at Hector

Hector, New Zealand

Hector and Ngakawau are two lightly populated settlements located at the mouth of the Ngakawau River in the West Coast region of New Zealand. Both settlements are situated on State Highway 67 between Westport and Karamea...

.

The river is polluted with acid mine drainage

Acid mine drainage

Acid mine drainage , or acid rock drainage , refers to the outflow of acidic water from metal mines or coal mines. However, other areas where the earth has been disturbed may also contribute acid rock drainage to the environment...

 and coal

Coal

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 fines from the Stockton Mine

Stockton Mine

Stockton Mine, on the Stockton Coal Field, is New Zealand's largest opencast mining operation. The entrance to the mine is at the former settlement of Stockton....

 and the proposed Stockton Plateau Hydro Project

Stockton Plateau Hydro Project

The Stockton Plateau Hydro Project is a proposed hydroelectric power station planned on the Ngakawau River in the northern section of the West Coast of the South Island of New Zealand....

is expected to reduce the levels of pollutants.

The Ngakawau Riverwatch environmental group formed in 2001 to address the water pollution in the river.