The Martha mine at Waihi

A pit at the end of the main street

Robert Lee and John McCombie started digging here and gave up. William Nicholl later found their workings, sank a shaft, marked out a five-acre claim and named it Martha after a member of his family. Smaller claims around it were merged into the Martha Company, and a battery was soon crushing the gold-bearing rock. The ore was low grade, and once industrial cyanide processes made it pay, the Martha grew into one of the world's most important gold and silver mines. Waihi grew with it. By 1908 it was the fastest-growing town in the Auckland Province, three times the size of Hamilton.

Underground, water was the enemy. In 1904 the Waihi Gold Mining Company built a concrete pumphouse on a Cornish tin-mine pattern for a huge steam pump, which drew water up the No. 5 shaft at around 400,000 litres an hour. Electric pumps took over in 1913, though the Cornish engine was kept in working order until 1929. The horizontal workings grew to more than 160 kilometres.

In 1935, in the middle of the Depression, New Zealand's gold output peaked, and two thirds of it came from the Waihi Company, the largest of the four big producers. By the 1950s the mine was struggling. The gold price was fixed at US$35 an ounce, the machinery needed money nobody had, and two world wars and the Depression had drained the workforce. The underground mine closed in 1952, after producing about 5.6 million ounces of gold and 38.4 million ounces of silver.

When the gold price rose in the 1970s, prospecting found ore that could be worked more cheaply from the surface, and the Martha reopened as an open pit in 1988. It has averaged around 100,000 ounces of gold a year since, at a cost to the town. In 2001 subsidence brought down a house, and the company agreed compensation for about 130 households troubled by noise, blasting and dust. Large landslides in the pit stopped mining in April 2015 and again in April 2016, and in 2018 OceanaGold announced Project Martha to rebuild the haul road and restart. Since 2004 more underground mines, Favona, Trio and Correnso, have been driven beneath much of the town.

Subsidence also threatened the pumphouse, a Category 1 historic place since 1983. In 2006 the 1,840-tonne shell was braced inside and slid 300 metres over three months along Teflon-coated concrete beams to safer ground. It stands off Seddon Street, open to view in daylight hours.