You sound like you're panicking which prevents you from thinking clearly.
We still have at least 5 months before our dam levels reach 10% (without other interventions). It is acknowledged that the last 10% is difficult - but not impossible - to retrieve. Provisions have and are being made to extract groundwater but you ignore this. The desalination plants are a problem but this does not mean that they won't happen. No individual implementation solves the problem which is why a multi-pronged approach is being used. We can expect a constrained supply but the many boreholes already installed means that we won't actually run out. Business will not shut down en masse. You have no faith in human innovation.
I notice that you are unable to tell me how much less water would be used if all developments stopped and how many jobs would be lost.