Tarawera River on the Rangitaiki Plains
|- location||Bay of Plenty|
|Length||65 km (40 mi)|
|Basin size||906 km2 (350 sq mi) (measured up to Awakaponga)|
|- average||26 m3/s (920 cu ft/s)|
It flows from Lake Tarawera, northeastwards across the northern flanks of the active volcano Mount Tarawera, and past the town of Kawerau before turning north, reaching the Bay of Plenty 6 kilometres (4 mi) west of Edgecumbe.
The Tarawera Falls on the river are considered to be quite spectacular.
The Tasman Pulp and Paper Mill, now owned by Norske Skog, has been discharging waste into the river since 1955. Local residents have erected signposts labelling the river as the "Black Drain" since the 1990s.
The dark colour is due to the presence of pollution from farms, sewage and stormwater but it is predominantly from pulp and paper mill effluent. As of 1997, pulp and paper mills were discharging over 160 million litres of industrial waste into the river per day. By 2006, the oxygen levels in the river had reached a level where fish could survive, however the water colour was still dark. Since 1998 the colour and light penetration (euphotic depth) have improved in the lower section of the river due to less pollution from the Tasman Mill.
In 2009, the mill gained permission to continue polluting the river for the next 25 years. In 2010, local iwi took a case to the High Court to shorten the 25 year water discharge permits issued under the Resource Management Act but the appeal was rejected.
- "Iwi not giving up fight against Tasman mill discharges". Radio New Zealand. 18 December 2010. Retrieved 18 December 2010.
- Park, Stephen (February 2008). "Colour and Clarity of the Tarawera River 1991-2008" (pdf). Environment Bay of Plenty.
- "The State of New Zealand's Environment". Ministry for the Environment (New Zealand). 1997. Archived from the original on 2008-10-16. Retrieved 2008-03-23.
- "Mill gets 25-year pollution consent - Business - NZ Herald News". Nzherald.co.nz. 2009-10-16. Retrieved 2013-09-06.
- Media related to Tarawera River at Wikimedia Commons