It's happened: Thames Water have applied for a drought order.
We've just heard this in the past half-an-hour so there's no real details yet but apparently the restrictions will not be put into force immediately.
There was a drought order put in place by Sutton and East Surrey Water in May (the first in the UK in 11 years) which extended the hosepipe ban to to add restrictions on sports grounds, parks, car washes and window cleaners. So that's what to expect.
Of course, it's all Tony Blair's fault.
"We simply don't know how much rain we will get in the rest of the summer. If the weather is unusually hot and dry we will need to restrict water use more than we are at present."
Water company in 'can't predict weather' dilemma!