Case Study

Kopuatai Peat Dome

The Kopuatai Peat Dome has a total area of 9,665 hectares and is the largest wetland in the country. It is located on the Hauraki Plains and bounded by the Piako and Waihou Rivers and the Elstow Canal. The Dome has National Reserve status and has been identified as having international significance. Only part of it is in the Matamata-Piako District. It is remnant of that huge wetland, which once stretched from the Firth of Thames to Matamata, and from the Kaimais to the western ranges.

The peat dome is created by vegetation partly but not fully decomposing. In the centre of the swamp, water cannot drain away so the whole area is waterlogged. Because of the lack of air in this part of the swamp, dead plant material does not break down or decompose. Round the edge of the swamp however, where the water can drain away, oxygen can get into the vegetation and cause it to rot.

This peat swamp is particularly important botanically because it contains the rare Greater Wire Rush, which is found only in three places in the world. There is also a wide range of other rush species in the wetland as well as clumps of stunted manuka, flax and cabbage trees. The wetland is an important habitat for fernbirds, bittern, pukeko and harriers.

Kopuatai is a refuge for rare plants and is very vulnerable to change. It is also part of our vanishing national heritage. It is important that it be managed and protected in a manner that will sustain it.

This expansive area of wetland could well be considered to be an “invisible” part of the District’s landscape. Despite its size the wetland is difficult to view, because the surrounding land is low lying and the vegetation of the wetland is of sombre colourings and low stature. There are very few features, which stand out with the exception of fence lines and the occasional tree. In places land surrounding the wetland is being drained by means of canals for use as grazing land. This can adversely affect the functioning of the wetland.

Roads surround the wetland and carry a reasonable amount of traffic, though there are few houses in the area.

There is a conflict between the conservation of the peatland and the development of surrounding land. The development of surrounding land usually always involves the drainage of the land, as it is all peat. This drainage can result in irreversible shrinkage and oxidation of the peat dome.

The Matamata-Piako District, utilising resources from Environment Waikato and the Department of Conservation are monitoring the health of the Kopuatai Peat Dome and continue to assess the impacts of adjacent farm drainage activities.