In 1970 the Labor-led South Australian government headed by Don Dunstan was concerned that Adelaide would become overpopulated following rapid population growth caused by a high birth rate and high rates of immigration in the two decades prior. In total population growth was in excess of 3% per annum and the government estimated the city would reach 1.5 million by the end of the century. Further, the authorities believed that the growing population would sooner or later become a threat to the quality of urban life (social and environmental) which at the time was relatively high. An expansion of the city would also threaten the attractive wine producing areas that could be found in the south and north of the city.