There are simple facts which the City does not seem to want to understand: the population has doubled from about 2m in the last decade or so "the Western Cape's population growing by nearly 1.5 million people over twelve years." http://worldpopulationreview.com/world-cities/cape-town-population/ to almost 4m today. In that time no new water resources/dams/desalinisation/aquifer access have been added. Cape Town has been marketed as the premier tourist destination in Africa and the local economy relies on the (hopefully) extra 1m tourist spend creating work for 100's of thousands of locals. 

If there is no "comfort zone"water access, tourists will go elsewhere (we are a long haul destination) and the economy will fail. 

Water used to be seen as a "free civil right" but as the Western Cape weather patterns change, everyone should now pay for water, based on property value. This will instil responsible usage and create funds for large 500m litre per day desalinisation plants.