As the human population of Australia increased, the incidence of severe
drought finally caught up with many of the urban residents of the country
from the early 2000s. A significant and extended dryer-than-average period
affected much of eastern Australia and began threatening urban water
supply from about 2002 to 2004. Similar dry periods had occurred previously
but affected rural Australians more than urban people, as most urban people
had been reliant on rainwater from tanks until the second half of the 20th
century. Ironically the conversion of cities to central supply (primarily from
large dams) and the prohibition of water tanks in cities contributed to an over
reliance on the principle climate sensitive supply source.