The bat charts illustrate how the water levels of six cities in Australia varied in October 2009 and 2010.
Overall, the amount of water in four cities (Sydney, Melbourne, Perth, and Canberra) increased by varying degrees, while Darwin showed a decrease and Brisbance witnessed stable levels throughout the period.
Regarding Sydney and Canberra, their water volumes were far higher than those of the remaining regions. The former started at around 78% of maximum, and then it steadily rose to 80% in October 2010. Similarly, that of the latter was 76% of maximum, slightly lower than the water levels of Sydney in October 2009, after which its rate grew significantly to roughly 100% in October 2010.
Melbourne and Perth witnessed a similar upward trend. In October 2009, the water degrees of Melbourne were only about 22% of maximum, around half that of Perth. Then, both showed growth to 40% in Melbourne and 70% in Perth by the end of the period.
In terms of remaining regions, Darwin saw a decrease from 45% to 23% in October 2009 and 2010. Conversely, the amount of water in Brisbane remained unchanged at 58% in both years surveyed.