Cape Town, the legislative capital of South Africa and a modern city of approximately 4 million people, is literally running out of water. April 16 is currently designated as ‘Day Zero’ – the day when the city will run out of water. A Cape Times article in April 1990 warned that the “City will run out of water in 17 years”. Some 28 years on, that audacious prediction is perilously close to being realised, which would be a world-first for a major city in modern times.

Aither and Global Change Advisory have been working in partnership with the DFAT-funded Australian Water Partnership in a number of countries beset by acute water scarcity problems, including Jordan, Iran and Mexico. There are common threads in the water stories in each of these countries that bear striking similarities to the Cape Town situation. All have experienced a combination of rapidly increasing water demand and diminishing water supply. These changes have taken the form of a slowly unfolding drama that attracts attention only when crisis point is reached.

The Cape Town water crisis has been characterised as a bad drought, implying that the problem will go away once the rains return to normal. But what if they don’t? They didn’t in Perth and there are indications that they may not do so in Cape Town.

Perth experienced an 87% reduction in inflows to its water storages compared to its long-term average for the period 1911–1974, brought about by a step-change decrease in rainfall that started in the mid-1970s (see figure). Accepting that they have undergone a climate shift, Perth’s water supply managers have now moved to a ‘zero inflow’ setting, substituting catchment flows with a combination of groundwater, desalination and recycling.

Observations and predictions published by climate scientists indicate that global warming is causing changes in the general circulation of the earth’s atmosphere, affecting patterns of rainfall. One of the clearest trends apparent is the drying of the mid-latitude areas in both the northern and southern hemispheres. Virtually all global climate models indicate that rainfall will decline in these areas through this century. Our recent missions to Iran, Jordan and Mexico have revealed that these countries are showing acute symptoms of climate driven water scarcity.

Despite the many warnings and indicators many countries still struggle to introduce timely water policy and planning responses to arrest their progressively deteriorating water supply/demand imbalances. Reforms such as capping extractions, licensing and monitoring water withdrawals, recovering the full cost of water and drainage services and augmenting water supplies with climate resilient sources such as recycling and desalination, are often put in the ‘too hard basket’ for too long. As Australia learnt during the painful Millennium Drought (1998-2010), the longer that such problems are ignored the harder and more costly it is to implement reforms to bring our water systems back into balance.

The UN/World Bank’s High Level Panel on Water has been the catalyst for the development and deployment of WaterGuide in Jordan, Iran and Mexico. At the heart of the WaterGuide organising framework, is the need to address the issues currently placing Cape Town in crisis. Determining realistic supply and demand forecasts and marrying those with effective water policy and planning strategies and actions, so that Cape Town, and many others to follow in the near term can be placed on a sustainable footing. We certainly don’t have another 28 years in which to not recognise the step-change that is upon us and the responses that will be required.