You may not have noticed it, but parts of the UK have not been getting enough rain recently.
The problem is particularly bad in Southern England. Two unusually dry winters have left the reservoirs there only about half full. In the Thames water region, around London, there's been less than 70% of the rainfall that was expected since November 2004.
This means that less water has soaked into the ground, where it is needed to feed the wells and rivers that the water supply relies on. To help save water millions of people living in these areas are now covered by a hosepipe ban.
The falling supply of water is becoming a big problem because we are using more water now than ever before. Twenty years ago the average person used 140 litres a day, today it's 163 litres and in 20 years time it's predicted to be 183 litres per person - per day.*
*Figures from Thames water - for more info follow the link at top right