Stockton

The Stockton open cut coal mine operated by Stockton Alliance is owned by a joint venture between Downer EDI Mining New Zealand and state owned mining company, Solid Energy New Zealand Limited. It is the largest open cut mine in New Zealand and is located 35 kilometres north of Westport on the South Island's West Coast, between 500 and 1,100 metres above sea level. The environment surrounding the Stockton mine is one of high rainfall (6,000 mm a year), many days of mist and low cloud, cool temperatures, the occasional snow fall and morning frost.

The Stockton Mine has a Life of Mine to 2028

The Stockton mine contains sufficient coal resources for it to continue producing coal up until 2028. It contributes greatly to the New Zealand economy, particularly the throughput at the Lyttelton Port at Christchurch and KiwiRail's Midland railway line. A high proportion of Stockton coal exported from New Zealand is shipped to leading coke makers and steel mills in Asia.

Two Million Tonnes of Coal Produced at the Stockton Mine Each Year

The Stockton underground coal mine produces an average of around two million tonnes of high quality coal a year and is continuing to develop further resources in the area. The Buller Plateau, where the Buller coalfield and the Stockton open cut mine is located, has very little topsoil, owing to centuries of heavy, constant rainfall. This has also effected water chemistry and led to Solid Energy developing expertise in managing water quality issues, the management of wildlife, pest control and rehabilitation of mined out areas.

Stockton Coal Seams are Close to the Surface

Coal is mined from seams just below the surface at the Stockton open cut mine. This means that when developing an area for mining the work has to include a system that is able to divert clean surface water away from the area to be mined. Water collected within the worksite area that carries sediment with it, is channelled into the Stockton mine water treatment infrastructure. The soil and vegetation taken from above the area being prepared for mining is carefully lifted and transported to a holding area. It is held here to await use again when needed for rehabilitation when the area eventually becomes mined out.

Stockton Mine Management has Developed its Own Unique Manner of Rehabilitation

The Stockton mine, through Solid Energy, has developed a way of picking up and moving clumps of mulch and top layer material containing soil and all its living organisms. By preserving these important elements the rehabilitation of the site is substantially accelerated when the time arrives for this phase of mining to be carried out. Over 30 hectares of rehabilitation is completed at the Stockton coal mine each year. Much of it involves the planting of many hundreds of thousands of native seedlings. The seedlings are propagated and nurtured in a number of nurseries from seeds collected at the mine site. Because of the very high rainfall washing away most of the top soil over time the hardiness of the plants used in the rehabilitation process have to be native to the area and quite hardy.

Solid Energy is the largest coal mining company in New Zealand, it is state owned and established in 1987 from the New Zealand government's former department, State Coal Mines. The company's coal mines have an average coal production of around four million tonnes with 70 percent used in the making of steel.

The mine employs more than 500 people directly and creates work for a further 200 who carry out contracting and consulting work for the company. Many national and local businesses rely on income for work carried out on behalf of the Stockton mine.