The disastrous storm of 1868 forced Oamaru’s leaders to take stock. Virtually all passengers and cargo moved by sea, so ports were vital to towns. Oamaru’s dangerous harbour made insurance expensive – merchants knew that they had to make their port safe, or fall behind rival towns.
In 1872, therefore, after abandoning the idea of building a small dock in the Brewery Lagoon, they started constructing a large concrete breakwater. From 1875, when the small Macandrew Wharf opened against its sheltered side, shipwrecks virtually ceased.
The Oamaru Harbour Board was formed in 1874. It completed extra wharves later that decade, and by 1884 it had finished the breakwater, built the big Sumpter Wharf for the frozen-meat trade and acquired a dredge.
Although the new South Island main trunk railway line (1878–9) killed the Dunedin ferry service, freight business grew steadily.
Sumpter Wharf, the big pier completed in 1884, was designed for the new frozen-meat trade. A freezing works opened near the port, and soon the harbour was busy with ships loading mutton and lamb. The Elderslie, the first steamer designed for the United Kingdom–New Zealand meat trade, ran between Oamaru and London direct.
Building this huge port stretched the harbour board’s finances. The 1890 Maritime Strike did not help either, disrupting trade for several months. In 1891 the board defaulted on its loans and was later placed in receivership.