Southland's largest conservation battle was the fight to save Lake Manapouri from being raised.
It had been planned to raise Lake Manapouri by 11.3m to achieve maximum efficiency for the hydro project but in the face of determined opposition, the plan was scrapped in 1971.
In 1972 the Government decided that Lakes Te Anau and Manapouri would be controlled but within their natural levels. The Te Anau control gates were built in 1974 and the Manapouri ones in 1977.
The gates are used to maintain a minimum 16 cumec flow in the Waiau River, a maximum and minimum level for the two lakes and an ongoing supply of water for the power project of about 500 cumecs.
Beer boycott
Southland's beer boycott took place in 1970.
Ohai miners, angered that the price of a jug of beer had risen from 40c to 43c boycotted the local hotel for eight months and got their supplies from the Licensing Trust in Invercargill instead.
The boycott failed and miners eventually paid the higher price.
In its heyday Ohai had a school, lots of shops and a hotel but there is little left in to town today.
Spraying sandflies
New Zealand's first aerial insecticide spraying was to control sandflies in Milford Sound on January 6 1959. A Tiger Moth spread a mixture of DDT and diesel.
Tourists at Milford Sound are unlikely to notice any long-term benefits from this misguided effort.
Sandflies only live a few days and their larvae live in water.
DDT is an indiscriminate killer of insects and without the Milford Sound insects there would be no fantails, robins or tomtits.