The Tarawera River flows for 65km from Lake Tarawera, past Kawerau before turning north where it reaches the Bay of Plenty coast about 6km west of Edgecumbe.
This is a river that has been subjected to the obvious effects of industry and human interference. In the 1950s, the Tasman Pulp and Paper Mill began discharging waste into the river. As late as 1997, it was reported that Tasman was pumping over 160 million litres of industrial waste into the river every day. Mill waste combined with farm run off, sewage and stormwater discoloured the river water. Such was the ecological disaster, oxygen and toxicity levels in the river were at a point where fish were barely surviving and tannins and lignin waste from the wood products manufactured at the mill turned the water black. Local residents nicknamed the river "the black drain". The river was on the brink of certain death.
In the years since the 1990s, a series of process and operational changes at the mill has helped to reduce the amount of contaminants entering the water. The mill scaled back some of its operations and set targets to reduce waste discharge into the river. This fell from more than 100 tonnes a day to about 15 tonnes, with a goal to cut this further, to less than 10 tonnes. Under the Resource Management Act, the council assumed responsibility for managing and monitoring water quality. The health of the water was monitored by the council and included regular site visits, audits, water quality sampling, water temperature, flow and pH (acidity) levels.
Today, the Tarawera River is not perfect, but it is in a much better state than formerly. Trout have returned - and in numbers near to normal for a river of this size and scale - and people are catching whitebait in its waters. The river's ecology is getting closer to what you'd expect in a natural pristine state - it is a major success, a huge change, especially when you consider where it has come from.
The cache: You are looking for a concealed bison. Bring your own pen/cil. There is enough safe, off road parking nearby.