Steve Munro considers changing attitudes to the land in Central Otago.
Before Māori settlement, the plains and river valleys of Central Otago were covered in podocarp-broadleaf forests, with smaller areas of beech forest.
At higher elevations, shrublands and tussock grasslands predominated. Archaeological and ecological evidence suggests that Māori used fire to clear parts of these forests to flush out game, cultivate food and create travel routes. These activities marked the beginning of a long sequence of human land-use practices that have continued to shape Central Otago’s environment.
European settlers, encouraged by successive governments’ mantra of ‘‘clear the land, clear the land’’, continued the transformation of the landscape. They introduced exotic plants and animals to establish the region’s first farms.
Along with farming livestock, settlers brought exotic grasses, crops and trees, as well as weeds and pest species such as rabbits, that would later have significant ecological impacts.
Gold-mining was another major early land use. Although largely unregulated by modern standards, the industry brought economic prosperity and a surge in population. Many of the remaining relics of gold-mining now have heritage protection and contribute to the region’s present-day character. Mining has continued in and around Central Otago at varying scales.
As economic conditions evolved, farming diversified. Ironically, exotic pine plantations were sometimes established on land that had previously been cleared of native forest. Seeds from these plantations spread rapidly and wilding pines have since become a major ecological pest, alongside earlier introductions such as gorse and broom.
Two of the more visible modern land uses in Central Otago are vineyards and dairy farming. Both have expanded rapidly in recent decades, supported by extensive irrigation schemes. While these activities have generated significant economic benefits, they also present environmental challenges.
Central Otago’s long history of power generation dates back to the 1880s, when a hydro-electric scheme was built at the Bullendale gold mine in Skippers Canyon. The most recent major development is the Clyde Power Station, commissioned in 1992, which required the formation of Lake Dunstan. The lake submerged about 2600ha of land previously used for agriculture and settlement. Studies continue today into the feasibility of the proposed Lake Onslow hydro-storage scheme, which would inundate an additional 800ha of land around the existing man-made lake.
Central Otago has long been a popular holiday destination for New Zealanders and, more recently, a desirable place for permanent residence. To accommodate population growth, significant areas of land once used for agriculture have been converted to residential development.
However, the pace of this conversion has at times outstripped the development of necessary infrastructure. The discharge of treated wastewater directly into the Shotover River from the Queenstown Lakes treatment plant is one example of this pressure.
Another potential land use under consideration is the construction of an international airport at Tarras. While an airport would represent a new use for this specific site, the region already hosts several airports, including those at Queenstown, Wanaka and Alexandra. About 800ha of land have been bought for the Tarras proposal to date.
The proposed Santana gold mine at Bendigo represents another stage of the region’s evolving land-use story. The company’s Bendigo-Ophir exploration permits cover about 25,100ha - comparable to the 27,492ha associated with the Macraes mine in East Otago - although the area subject to the current mining permit application, the Rise and Shine prospect, is significantly smaller at about 800ha. The proposed main pit would cover about 85ha.
To put this into perspective, the Jacks Point residential development could accommodate roughly 24 pits of this size.
The legacy of early European agriculture remains visible today. While farming continues to provide important economic returns, its environmental effects are also evident.
Despite this impact, the region’s ‘‘unspoilt’’ landscapes are often celebrated as part of New Zealand’s clean, green tourism image.
A closer look, however, reveals the ongoing environmental pressures associated with human activity. Large areas of wilding pines have been aerially sprayed with metsulfuron; glyphosate continues to be used at domestic and agricultural scales; and effluent from dairy farming is regularly discharged on to land.
The Santana project will require careful management of processing chemicals to ensure that environmental effects are contained and monitored. While the environmental impacts of the project will be highly localised, the scrutiny it receives is likely to exceed that directed at many other land uses in Central Otago.
The ongoing challenge for Central Otago is to evaluate and manage the cumulative impacts of these existing and yet-to-be identified competing land uses; pastoral farming, dairying, cropping, forestry, viticulture, energy generation, infrastructure, mining, housing and others.
Each provides opportunities and challenges and each, along with Santana’s project, situated in an already modified landscape, represents a legitimate land use.
• Steve Munro has a background in physical earth sciences and a general interest in historic and contemporary land uses.
