Last year was one of the driest on record. Following below-average rainfall for 18 of the last 23 months, groundwater levels in parts of our region are lower than they were during the 1976 drought.

It's now not a case of whether we'll be having a drought this year, it's a case of when and how bad.

Droughts are not caused by a few dry weeks and they aren't solved by a few wet ones. We need well above average rainfall from February to April to reduce the risk of a drought to a low level and while we can't control the weather, all of us can help by using less water - because the less we use, the more there'll be to go around later.

Where our water comes from

Across our region, we take about 70 per cent of our source water from rivers, in a process called abstraction.

We then store this in large, open reservoirs (known as surface reservoirs) before putting it through our treatment process to turn it into drinking water. 

The remaining 30 per cent comes from underground boreholes, from which we pump water which has originally fallen as rain and sunk down into the ground. These supplies are referred to as groundwater.

Reservoir and water levels

The diagram below shows the rainfall and levels of water in the rivers, reservoirs and underground in our area, for the last month.

Water situation summary January 2012

• The dryness of the ground across our region was above average for the end of January.
• Despite above average rainfall last month the majority of river flows remained below average for the time of year.
• The levels of groundwater generally remained below average for the time of year.
• Our London reservoirs were 92 per cent full and our Farmoor Reservoir in Oxfordshire was 99 per cent full on 31 January 2012.

Rainfall in the last month

We had 43.7mm of rainfall across our area from 1 to 31 January 2012, which is 64 per cent of the 128-year monthly average.

Rainfall in the last 12 months

The graph below shows whether the rainfall for each of the last 12 months was above or below the 128-year monthly average for the Thames catchment.