Worth bearing in mind that it's 15 years since the government rejected a new strategic reservoir for the southeast (near Oxford). They claimed Thames Water hadn't made the case for it (to me it looked like they had) Interestingly Thames Water now say it needs to be 50% bigger than what was proposed

Abingdon £1bn reservoir plan rejected by governmentPlans for a £1bn reservoir in Oxfordshire to supply more than eight million people over the next 25 years are rejected by the government.www.bbc.co.ukDan Grey

It hasn't rained in parts of Devon for 50 days (I last had rain on 22 June) Southern England has only had 1% of the usual July rainfall The Environment Agency has now decreed a "flash" (sudden onset) drought for much of England