Research and analysis

South London groundwater situation: March 2026

Updated 1 April 2026

Applies to England

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Current situation

Groundwater levels started to increase sharply for a brief time at the end of February 2026, following rainfall received in South London. However, due to the lack of significant rainfall since the end of February, groundwater levels are now falling.

Groundwater levels are now normal for this time of year in South London.

Short term forecast 

Weather forecasts for the next 2 weeks indicate that there will be periods of fine weather with light intermittent rainfall and scattered showers at times, however daily rainfall totals are not expected to exceed a few millimetres. As a result, groundwater levels are expected to continue to fall.

Longer term forecast 

Weather conditions 2 to 4 weeks from now are predicted to remain relatively dry, with only light and patchy rainfall currently forecast. If rainfall over the next few weeks remains as low as expected, groundwater levels would be expected to fall.

Graph showing the trend of groundwater levels since June 2024 at the Woldingham Observation Borehole in South London overlying a background of colour banding indicating relatively high and low conditions. Levels are normal for this time of year as of 31 March 2026.

What the Environment Agency is doing 

We will continue to monitor groundwater levels across South London and provide situation report updates, if the outlook changes. If there is no significant change to the current outlook, the next report will be published during the next recharge season (October to March), when groundwater rises again.

We will take evidence-based decisions and if conditions deteriorate, we will notify our partners (including lead local flood authorities and water companies). We will also actively engage with our partners to help them prepare for incident response.

Actions and advice

There is practical advice on what to do before, during and after groundwater flooding, and further guidance about groundwater flooding, how it might affect you and what to do

Next update

We will continue to monitor groundwater levels closely. If there is no significant change to the current outlook, the next report will be published during the next recharge season (October to March), when groundwater rises again.

Further information

You can view:

Contacts

If you have any questions, email enquiries@environment-agency.gov.uk.

The Environment Agency offers free Groundwater Flood Alerts. You can:

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