Golden Cross

The Golden Cross gold and silver mine is one of few examples in New Zealand of a mine proceeding through development, operation, and closure since 1990.

 

The Resource Management Act 1991 applied during mining and after the mine closed, with consents and conditions for disturbance of ground, management of rock materials including tailings from ore processing, discharges to freshwater, and site rehabilitation.  

Before

Like many NZ mines, Golden Cross was developed on the site of historic mine workings. Between 1895 and 1920 the old-timers produced 80,000 oz. of gold from underground workings from the area, located 8km northwest of Waihi in the Coromandel. Golden Cross reverted to farmland until prospecting and exploration in the 1970s and 1980s revealed further potential. A mineable resource was indicated on the 27th exploration drill hole.

During

Between 1991 and 1998 Golden Cross produced 660,000 oz of gold and 1.7m oz. of silver. At its peak the mine employed 243 staff, with an additional 750 employed in service and support industries. In 1993 Canada-based Coeur d'Alene Mining Corporation, and a New Zealand company, Viking Mining, bought Golden Cross, and operated it as a joint venture until after the mine closed.

Golden Cross presented the typical elements of a hard rock metal mining operation. Ore and waste rock (overburden) were extracted from an open pit. A rock-crushing and chemical processing plant produced gold and silver on site. Left-over rock from this process was built into a tailings storage facility. Other waste rock was stored elsewhere on site. A water treatment plant converted all surface stream and run-off from the site into potable water, returned to the natural stream.

In 1998 the tailings storage facility suffered a loss of engineering stability, installed as it was on steeply sloping land. The mine closed, with mineable gold and silver left in the ground.

After

The mining company immediately closed the mine. The tailings storage facility was stabilised and converted into a wetland, consistent with resource consent conditions. Waste rock partially refilled the open pit, and the slopes were re-contoured. This area, and other disturbed ground were covered in soil, and sown in grass and trees. Infrastructure was removed, except for the water treatment plant. The regional council, Environment Waikato, was vested with a contingency fund for any additional work.

Today

Golden Cross today is working farmland once more. The wetland is ringed with native vegetation and frequented by waterfowl. The water treatment plant continues to operate. Barely a trace of mining activity remains.