Serving parts of North West London and the Home Counties.

Groundwater Levels

South East Region


South East water levels hydrograph

*The long term average (LTA) has been calculated statistically, using the long term data record for this hydrograph. The respective drought zones are used as operational triggers, and have been derived using the LTA.

*Drought zone 1 is the LTA in South East region.


Groundwater levels are currently in drought zone 1, just above the level at the end of March 2018. They saw a substantial recovery during December 2018 but a reduced rate of recovery from January to March 2019, largely caused by below average rainfall during January and February. March has been wetter and the Southeast region has received rainfall in excess of 120% of the LTA. This has reduced soil moisture deficit, increasing the likelihood that rain which we receive through April will recharge the Chalk.

Groundwater levels are expected to start to decline through April if they follow the LTA trend. Under a 100% rainfall scenario, because of the reduced rate of recovery through early 2019 compared to the LTA, we would expect to remain in drought zone 1 for the remainder of the year. Lower rainfall scenarios (such as 60% or 80% of the LTA) may see us breaching drought zone 2 in autumn 2019. Even under such a scenario, levels would likely remain above those of autumn 2017.