The bar chart above illustrates the water reservoir levels in six metropolises over one year in October 2009 and 2010.
What is most striking when looking at the chart is that the majority of the cities recorded a significant increase in water levels to various degrees, with Perth accounting for the highest margin. On the other hand, Darwin was the only city to end the year with a marked fall, and Brisbane with no change.
Looking first at Sydney and Canberra, they were both documented as having the highest water levels inside their reservoirs. In October 2009, Sydney had its water tanks nearly 78% filled, the highest among the figures examined in the same year. Although it had been slightly edged out by Sydney from the start, Canberra ended the time frame by nearly reaching its maximum capacity, with a staggering 20% increase. Conversely, the “started strong” city only had a minute rise of around 3 percentage points.
A more pronounced increase was seen in Melbourne and Perth, especially the former, which nearly doubled the water amount inside its tanks, from around 21% to 40% after a year. Interestingly, the same figures amounted to around half of the corresponding percentages for Perth.
Contrary to the pattern seen in the four aforementioned cities, Darwin experienced a dramatic decline in its water levels. Starting at an already moderate 40% of their water threshold, the city’s reservoir level tumbled to roughly half of what had been recorded exactly one year later.