Scientist predicts “a total system crash in March 2018” for Cape Town’s water supply

26 October 2017

The slow onset crisis unfolding in South Africa is – at least in my professional opinion – about to enter a new phase. Gauteng came within a week of running out of water last year, saved only by a major rainfall event that fell literally deep into the eleventh hour. Many think that the drought has gone away, so they no longer worry. Cape Town is now where Gauteng was over a year ago. Unless it rains in the next 4 months, then the water supply will literally collapse by March 2018.

This is very serious, so I have decided to write this piece in a sincere effort to galvanize constructive debate in the public interest.

The dataset attached shows dam levels since November 2016. Remember that the Western Cape is a winter rainfall area, so we are now out of the normal rainfall season entering the dry season with dams less than 30% full. But this only tells part of the story. The second graph shows the combined total of all dams in the Cape Town metro area since 2014 as the blue line, with useable water as the red line. Note the following:

1) Distinct seasonal cyclicity as rain falls in the winter followed by a dry summer.

2) Useable water is always less than dam levels, because of losses and other factors.

3) Each peak since 2014 has been lower than the previous peak, with a near linear downwards trend over the last three years.

4) Each trough follows a similar trend, being lower than the previous cycle.

5) The data stops in October 2017 (present date) on a high that is lower than all previous highs in this dataset, so extrapolating historic data into the future, we see a total system crash in March 2018.

This is dire. In fact, this will be the first case of total system failure in thecountry. Without water commerce is not possible. Shopping centres cannot operate if they cannot flush toilets. Banks cannot have staff on the premises if they cannot use the toilet. Schools cannot operate if children are unable to remain hydrated and flush toilets (here the proxy is a school in Port Shepstone that was forced to send pupils home for the same reason). Hotels cannot provide for guests so the tourism industry fails. Hospitals cannot function so patients need to be transported elsewhere (here the most accurate proxy indicator is the Murchison Hospital near Port Shepstone where water supplies have failed). If a high-rise building should start to burn, then there is insufficient water to extinguish the flames (here the proxy is Braamfontein a year ago).

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The Cape Town water crisis: who knew?

17 October 2017

Unless some seriously impressive rains materialise in the very near future, Cape Town is facing a socio-economic crisis of note when the water runs out.  By comparison, the ‘hardships’ of the Eskom load-shedding times will pale into insignificance as millions of residents queue for their water ration.  City officials assure us that all is under control – but many of us are unconvinced.

Water ‘resilience’ has become a new buzzword, although melding ‘resilience’ with the emergency situation that the region finds itself in is a tad odd.  But there are lots of knee-jerk reactions in the mix and placating the public is obviously a priority.  Point of fact is, however, that the need for desalination in Cape Town by around the year 2000 was foreseen 47 years ago.

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The Cape Town drought: are more supply problems just around the corner?

5 October 2017

Bloom of toxic cyanobacteria in Theewaterskloof Dam(Photo: Bill Harding, 1991)

Bloom of toxic cyanobacteria in Theewaterskloof Dam(Photo: Bill Harding, 1991)

Monitoring for blue-green algae in times of drought – a need for increased vigilance:

The continuing and very troubling, ok downright scary is what it is, drought in the Western Cape should be on the minds of all those affected.  A major metropolitan area, plus numerous municipalities, are faced with the prospect of having to provide water from tankers at street corners in the not too distant future.  Millions of people will face considerable hardship, all the while having to continue to meet their daily obligations, be it family, work, education and so on.  Many work opportunities will be lost, at least temporarily.  The shortage of water problem could also, and rapidly, become a whole lot worse should what is left of the water become undrinkable.  Not everyone can afford bottled water. Read more »