A significant piece of Mohua Golden Bay history has been recognised by Heritage New Zealand Pouhere Taonga with the listing of the Onekaka Ironworks Quarries and Hydro-electric Power Scheme, and the Onekaka Ironworks Wharf and Tramline Piles.
Acting HNZPT Area Manager Central, Blyss Wagstaff, says the Category 2-listed Onekaka Ironworks Quarries and Hydro-electric Power Scheme built in 1922 and 1929 respectively, has historical, technological and archaeological significance as a physical link to an ambitious iron mining and smelting scheme.
"Many people will be familiar with the picturesque remains of the Onekaka Wharf, which was already heritage-listed for its connection with the Onekaka Ironworks. Now the remains of the ironworks’ quarries and hydro-electric scheme in the hills six kilometres away have also been entered on the New Zealand Heritage List," she says.
"The Onekaka Ironworks was a significant chapter in New Zealand’s attempts to establish an iron and steel industry. Although this undertaking ultimately proved uneconomic, the remains of the scheme’s infrastructure are a rare physical reminder of an enterprise which brought Onekaka to national attention."
Onekaka Inlet and the iron-oxide ores of the Parapara hills are culturally significant to the tangata whenua of Te Tau Ihu, including hau kāinga Ngāti Tama ki Te Tau Ihu, Ngāti Rārua and Te Atiāwa o Te Waka-a-Māui.
The Onekaka Iron and Steel Company was formed in 1920. Forty men were employed to construct smelting works on a terrace to the west of State Highway 60. The plant was fully operational by 1924, producing bars of pig iron suitable for making railway irons, stoves and pipes. An aerial tramway connected the quarries with the smelter site, and a tramline went between there and the wharf.
The ironworks were a major employer in the area and with over 81,000 tons of iron produced between 1922 and 1935, hopes were high for an enduring industry. Ultimately, the enterprise proved uneconomic, and the company was placed in receivership in 1931 before closure in 1935.
Government efforts to revive the Onekaka industry ceased in 1954. The ironworks were dismantled and subdivided for residential use, and bush reclaimed the quarries and the workers’ camp. The hydro-electric scheme continued however.
Blyss says the Golden Bay Electric Power Board used it to meet increased demand from 1937 until the Cobb Hydro-Scheme could supply all the load. “In 2003, the dam gained a new lease of life when it was resurrected by Onekaka Energy Company Ltd, and it continues to supply power to the national grid”.
The Onekaka Ironworks Wharf and Tramline Piles built in 1923-24, is a notable feature on the Onekaka coast.
"The aesthetic values of the wharf’s rusted vertical piles, a particular favourite subject of noted painters Doris Lusk and Enga Washbourn, continue to inspire artists, photographers and poets," says Blyss.
The wharf was reconditioned in 1941 in case it was needed during wartime but suffered storm damage in 1945. Today the wharf and the dam are the most prominent remains of a significant industrial undertaking.
The Heritage New Zealand Pouhere Taonga List entry reports can be viewed on this website here or by contacting Heritage New Zealand Pouhere Taonga.