It may feel like it rains a lot in the UK, but did you know that our capital city gets less rain each year than Rome, Istanbul and even sunny Sydney?
The latest news on average rainfall and groundwater levels in the Thames area
In May, we saw below average rainfall in the Thames Region. At 31.6mm, it was only 57% of the long term average (LTA).
On 31 May, the Thames Regional Soil Moisture Deficit (SMD) total was 82mm, indicating that our soil is drier than expected for this time of year.
Groundwater levels in the UK were also below average during May. Significant groundwater recharge will not begin until the SMD reduces.
Average rainfall in the Thames area
Check out our graph to see average rainfall in our region for this year so far:
Where water comes from
We rely on rain to maintain groundwater levels in our region.
Groundwater is the water that soaks into our natural underground reservoirs called aquifers. These supply up to 30% of the water we use every day across London and the Thames Valley. But that’s not all our aquifers do – they also help to keep our rivers flowing, which is where the remaining 70% of our water supply comes from.
River flow in South East England
In May 2019, many of our rivers were flowing slower than normal.
The Teddington Target Flow (TTF) was 800 Ml/d during May. The TTF is the minimum River Thames flow over the Teddington weir that is required to balance environmental, navigational and water supply needs. The TTF depends on the time of year and our reservoir storage, and is always agreed with the Environment Agency.
Saving for a rainy day – water levels in reservoirs
We store water in large, open reservoirs before we pump it to our world-class treatment plants, ready for cleaning.
We carefully monitor water levels in our reservoirs, regularly inspecting and maintaining the infrastructure to safeguard your supply.
At the end of April 2019:
- Reservoirs in London were 88% full (92% full in West London and 74% full in Lee Valley)
- Farmoor Reservoir in Oxfordshire was 98% full
Our water resources situation
Check out our infographic to see our water resource situation at the end of May: