On 15 August 2017 dam levels serving Cape Town were at 31% of capacity compared to 57% last year, 72% in 2015 and 101% in 2014. Meanwhile, consumption is still 100 million litres a day above the daily target of 500 million litres.
The reason we are at a critical moment in making it through to the next rainy season is that based on the probable increase over the remainder of this winter and spring of around 5%, we will only get to a maximum of 36%. Even if we have unusual rains going forward that get us to 40% of capacity, we still have a problem because 10% is too dirty to qualify as potable water. The effective maximum is therefore 30% in an optimistic scenario.
Looking back over the last few years, we have used about 40% of the overall capacity of the dams during the summer season. However, this was when the city’s consumption was above 800 million litres per day. At present consumption levels around 600 million litres per day, the dams would logically fall by 30% in the coming dry season which would make it touch-and-go as to whether the taps would run dry.
Hence, the necessity for the extra savings to be achieved right now in order to have some leeway in the next six months while the city lays the foundation for a sustainable water strategy in the long term.
In terms of the three short term scenarios I have offered in previous bulletins, Nature’s Gift, whereby the problem is resolved through abnormal rainfall in the next two months, is looking increasingly unlikely.
So we are left with Liquid Gold where the citizens of Cape Town collectively change their attitude to water consumption as do the tourists and all the industries in the vicinity. Innovative ways to increase supply temporarily or permanently are also implemented as is more recycling and the wider use of grey water.
Alternatively, we drift into Dire Straits where serious emergency measures are taken which inevitably lead to inconvenient disruption of people’s lives in order to ward off the worst possibility of no water at all. Water pressures have to be dropped considerably.
The wheel is spinning in terms of which of these two last scenarios will come into play but the most important flags to watch to decide between the two are the weekly figures on water consumption and the weekly dam capacity levels based on rainfall patterns.
Obviously, a green flag in favour of Liquid Gold would be the announcement of any measures which will increase municipal supply in a matter of weeks or months to get us through the crisis.