Southeast England is officially in a state of drought, the Department for Environment, Food and Rural Affairs (Defra) has confirmed.
The region joins other parts of eastern England that have been afflicted with drought since last summer. The country as a whole has experienced its driest winter since 1976.
Reservoirs, rivers and groundwater aquifers in the southeast are well below normal levels, with some even lower than the infamously dry summer of 1976.
Ardingly reservoir in West Sussex and Bewl in Kent are about two-fifths of their normal levels, according to the Environment Agency.
"Drought is already an issue this year with the southeast, Anglia and other parts of the UK and more areas are likely to be affected as we continue to experience a prolonged period of very low rainfall," said environment secretary Caroline Spelman after a summit meeting with water and weather experts
"It is not just the responsibility of government, water companies and businesses to act against drought. We are asking for the help of everyone by urging them to use less water and to start now."
Thames Water has already urged households to cut down on the amount of water they use.
The situation is in stark contrast to Scotland where reservoirs are between 93 and 97 percent full.
Richard Aylard, sustainability director for Thames Water, said: "We all need to recognise that the water coming out of our taps comes from our local river or from the aquifer that feeds that river - and the less water we all use the less we need to take from the river.
"It is no longer a case of if we have a drought this year but rather when, and how bad. This is not just our problem, it's everyone's problem and we can all do our bit to help - for example, turning off taps while we brush our teeth can save six litres of water a minute."