Rivers of New Zealand Rivers of New Zealand The rivers of New Zealand are used for a variety of purposes and face a number of environmental issues. Many of the rivers in the South Island are braided rivers. The longest river in New Zealand is the Waikato River with a length of . The largest river by volume is the Clutha River with a mean discharge of . Some of the rivers, especially those with wide flood plains and stop banks, have long road bridges spanning them. The Rakaia River is crossed by the longest bridge in New Zealand at . The third longest
Blackwater River (New Zealand) Blackwater River (New Zealand) Blackwater River is the name of three rivers in the northwestern South Island of New Zealand, one flowing into the Mangles River, one into the Buller River between Westport and Inangahua Junction (named due to the dark coloured waters the Māori discovered), and one into the Māwheraiti (Little Grey) River. All three rivers are within a few kilometres of each other, to the south and east of Westport. The easternmost of the three Blackwater Rivers flows due north along a long straight valley, parallel to and equidistant from, the Matakitaki and Tutaki Rivers, reaching the Mangles