Head of drought strategy at Thames Water Jerry White spoke to ITV News Reporter Martha Fairlie about the hosepipe ban coming into effect today.
He said the ban was necessary to ensure the company has enough water supplies for another dry summer.
Millions of homeowners have been banned from using hosepipes from today as drought grips parts of the country.
Deep underground, the drying-up boreholes of East Sussex show the extent of the UK's drought problem.
20 million people across the south and east of England will be hit by hosepipe bans that have come into effect since midnight.