Serving parts of North West London and the Home Counties.

Groundwater levels

SouthEast Region


Central region 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 Southeast region.


In Southeast region, groundwater levels are still in drought zone 1, in a better position than in our Central region. Levels are declining in line with the LTA, despite relatively high rainfall in June which was 172% of LTA for the region. This continued decline is due to warmer summer temperatures and high soil moisture deficit (SMD) which mean that less rainfall percolates down through the soil to recharge the aquifers. If they follow the LTA trend, groundwater levels will continue to decline until autumn/winter 2019.

The outlook is relatively healthy compared to Central region and suggests that levels may reach drought zone 2 under low rainfall scenarios (60% or 80% of the LTA) this year, although will recover out of it. Wetter scenarios are likely to result in groundwater levels tracking just below the drought zone 1 curve until the start of the next recharge period.