The real water crisis: Not understanding what’s needed
A serious multi-year drought in parts of South Africa’s Northern and Eastern Cape provinces has seen a number of small towns threatened by total water supply failures and livestock farmers facing financial ruin.
In other parts of the country, heatwave conditions and the late onset of rains have caused local supply failures. Although the dams that supply most of the main urban areas are still at reasonable levels, there are growing fears that the country may be witnessing the start of a major drought.
Cape Town’s experience of extreme “Day Zero” supply restrictions only adds to these fears. Weather forecasters seem unable to make reliable predictions more than a few weeks in advance. And there are nagging concerns about the government’s ability to identify and address emerging problems.
Unhelpfully, there’s no single water problem and the issues confronted vary widely from place to place.
In Cape Town, water managers thought they could avoid building new infrastructure to supply a growing population by encouraging everyone to use less water. A major drought proved them wrong.
During October’s heatwaves in Gauteng province, water ran dry as local reservoirs were emptied by residents who felt the need to use extra water for their gardens – and municipalities failed to enforce restrictions.
In Adelaide, Eastern Cape, where there has been a critical supply failure, one local councillor was reported to have commented that “the Adelaide Dam was at 1% before local authorities woke up”. Even then, there was little they could do because funding was not available.
The problems in Adelaide are repeated daily in towns and villages across the country as municipalities seek to expand the distribution of water without first ensuring that there’s enough supply or putting in place measures to control excessive use. Too often, poor planning and management is revealed when drought strikes, as is currently happening.
If there was more certainty about future weather, there might be less concern. But this is not the case. At the end of September, South African Weather Service forecasters said while summer rains would be late and October very dry, November would almost definitely see good rains.
And so far, so good, the rains in Gauteng started on schedule on November 1.
But South Africans shouldn’t expect that forecasting success to continue. It’s unusual for a seasonal forecast to be so confident.
For each three month period, the agency produces two rainfall maps. The first shows the “raw” predictions from the computer models and therefore aren’t statistically significant.
The second map is important because it shows only the areas where forecasters are reasonably confident that the predictions are significant or, in their terminology, sufficiently “skilful”. As a result, the second map is often almost completely blank.
As the first set of maps below shows, the predictions for the three months starting in November were very confident compared with the second set of maps which offered virtually no “skilful guidance” for the three months starting in September.
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