Research and analysis

Kent and South London water situation: January 2026 summary

Updated 17 February 2026

Applies to England

• Publication for Northern Ireland
• Publication for Scotland
• Publication for Wales

1. Summary

In January, the Kent South London and East Sussex (KSLES) area experienced significantly wetter conditions, receiving 195 percent of its long term average (LTA). Majority of the catchments recorded exceptionally high rainfall totals ranging from 184 percent of the LTA in the Darent and Eastern Rother catchments to 213 percent in the Lower Mole catchment. Soil moisture deficits (SMDs) continued to fall in January, remaining below average across all catchments, supported by January’s effective rainfall reaching 191 percent of the LTA. Monthly mean flows (MMFs) were above normal or higher at majority of the sites with the exception of the River Ravensbourne at Catford, River Darent at Hawley and the Dour at Crabble Mill which recorded normal flows for the time of the year. Groundwater levels increased at all the key indicator sites with levels at all sites within the normal range. Reservoir stocks increased in January, with levels rising at all sites except Weir Wood Reservoir which stayed stable.

2. Rainfall

In January, the KSLES area experienced significantly wetter conditions, receiving 195 percent of its LTA rainfall based on the whole area average. Almost all catchments in KSLES recorded exceptionally high rainfall, with the only exceptions being Thanet Chalk, Sheppey and North West Grain, which still experienced notably high totals. Rainfall across the area ranged from 184 percent of the LTA in the Darent and in the Eastern Rother catchments to 213 percent in the Lower Mole catchment. Overall, this made January the fourth wettest on record since 1991.

The top 5 highest rainfall days were 8, 15, 26, 21 and 6 January, with the highest daily rainfall total of 36.2mm recorded at Brede PS TBR in the Eastern Rother catchment on 8 January. In contrast, only 2 days across the entire KSLES area were classed as dry days, recording 0.2 mm of rainfall on both 5 January and 10 January.

3. Soil moisture deficit and recharge

SMDs continued to decrease in January across all catchments in the KSLES area, with all catchments recording values below the LTA for the time of year. This decline reflects the exceptionally high rainfall experienced throughout the month. By the end of December, most catchments reported SMDs of less than 1 mm, with the exception of Thanet Chalk and North West Grain. The effective rainfall recorded in January was 191% of the LTA average.

4. River flows

Monthly Mean Flows (MMFs) increased at all the key indicator sites in January, with majority of indicator sites recording flows in the above normal category or higher. Only three sites located in the northern part of the catchment – the River Ravensbourne at Catford, River Darent at Hawley and the Dour at Crabble Mill – recorded flows within the normal range for the time of year. Exceptionally high flows were recorded at the River Medway at Teston and the East Stour at South Willesborough, indicating a much stronger response to recent weather conditions.

5. Groundwater levels   

By the end of January, groundwater levels increased at all the key indicator sites across the area, with levels at all sites within the normal range. At Chipstead, groundwater levels increased significantly, moving from exceptionally low to normal. Nearby to the east at Sweeps Lane, levels rose from below normal to normal. Groundwater level across the rest of the area rose more steadily, with most sites showing gradual rises, reflecting the wetter than usual weather experienced through the winter period.

6. Reservoir stocks

Four out of five water company reservoirs in KSLES saw a rise in levels during January; Weirwood reservoir stayed stable throughout the month.

By the end of January, the reservoirs held the following live storage capacities and LTA class:

• Darwell – 92% above normal
• Bewl – 83% above normal
• Bough Beech – 100% above normal
• Powdermill – 100% above normal
• Weir Wood – 100% above normal

7. Environmental impact 

There were 61 fluvial flood alerts and 10 fluvial flood warnings issued in January.

Author: Groundwater and Hydrology Team, ksl.gwh@environment-agency.gov.uk

Contact Details: 03708 506 506

All data are provisional and may be subject to revision. The views expressed in this document are not necessarily those of the Environment Agency. Its officers, servants or agents accept no liability for any loss or damage arising from the interpretation or use of the information, or reliance upon views contained in this report.