Cape Town had water restrictions imposed a couple of years ago, which meant that regulation restricted the watering of gardens to evening and early morning and banned the use of a water hose to wash one's car, patio or any paved area.
Next summer will be the first summer that we'll have in our new home, so we'll still have to wait and see how much water our densely populated garden needs to survive. It looks to me as though many of the plants are relatively water-wise, but not being very green-fingered, I'm not yet sure.
It's becoming more and more important for South Africans to have only indigenous plants in their gardens. Indigenous plants tend to use less water and cope better with the dehydrating effect of the African sun.