Te Kopia Geothermal System has rare plants and other natural features, including a geyser that has built up a spectacular mud cone.
Te Kopia has steaming cliffs and ground, craters, a geyser, a mud geyser, hot springs, sinter deposits and fumaroles. Many of the features are found in a Department of Conservation reserve.
The Te Kopia Mud Geyser erupts a column of grey muddy water 5 to 10 m high as a single shot accompanied by a loud bang. These eruptions occur every 10 to 30 minutes when the geyser is active.
The geyser plasters surrounding vegetation in a thick layer of pale grey mud. It was active from September to December 2000 and manuka and kanuka shrubs within a 20 m radius were bent over under the weight of their mud coating.
Prostrate kanuka, large colonies of the rare ferns Dicranopteris linearis and Christella sp. 'thermal' and the rare bearded orchid Calochilus robertsonii are present.
The vegetation is considered internationally significant because it is the most intact remaining example of natural vegetation extending nearly 600m up the scarp, and is surrounded by mature native Kamahi forest.
Possibly connected to Orakeikorako geothermal system.
The Austrian geologist Hochstetter visited and described a geyser similar to the Te Kopia Mud Geyser in the early 1860s. He described its position at the bottom of the steep hillside and its size and activity. It is not thought that the currently active mud geyser is the same feature.
Te Kopia is classified as a Protected Geothermal System by Waikato Regional Council.
Stock grazing and future logging activities could crush sinter deposits. Possums, pigs and goats have damaged the native vegetation in the reserve, but these are now being controlled by the Department of Conservation.