Reservoir levels and rainfall figures

Last reviewed:

We had 73mm of rainfall across our area from 1 to 31 January 2016, which is 73 per cent of the 129-year monthly average.

Rainfall in the last year

The graph below shows the rainfall over the last year and percentage increase and decrease against the monthly average.

Where our water comes from

Across our region, we take about 65 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 35 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.

Find out more about where our water comes from

January 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 2017

  • Groundwater levels rose at many boreholes during the month but at the end of the month most sites were at Below Normal levels for the time of year.
  • The dryness of the soil across our region was average for January.
  • Flows were below their long term averages for most of January but many did rise in response to the heavy mid and end of month rainfall. At the end of January some were at or above their long term averages but many were still below. The Teddington Target Flow remained at 800 Ml/d during the month in agreement with the EA. 
  • Reservoir storage on the 31st January 2017 for London as a whole was 92% (Thames Valley 95% & Lee Valley 78%) and Farmoor storage was 93%.