There's no British Super Drought.
I think they mean the English Super Drought, or even the South-East English Super Drought. According to the BBC it's affecting:
Lincolnshire
Cambridgeshire
Hampshire
West Sussex
East Sussex
Kent
London
Surrey
Berkshire
Hertfordshire
Buckinghamshire
Oxfordshire
parts of Bedfordshire
parts of Northamptonshire
west Norfolk
east Gloucestershire
Not Wales or Scotland.
Why do the BBC do this? I know the UK isn't massive, but there are events that are not British but are specific to a particular area within Britain and should be noted as such. They did the same with the 'British Riots' last summer.
There's no sign of a drought where I am in the West of Scotland. It never bloody stops raining here.