Research and analysis

Kent and South London water situation: March 2026 summary

Updated 14 April 2026

Applies to England

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

1. Summary

Kent South London and East Sussex (KSLES) area received an average rainfall total of 22mm in March, which was 51% of the long term average (LTA). Rainfall was predominantly below normal across the area, with notably low rainfall recorded in eastern catchments and normal rainfall recorded further in the west. Soil moisture deficits (SMDs) across the KSLES area have increased from near zero in February to 24mm in March. Effective rainfall recorded in February was 22% of the LTA. Monthly mean river flows increased at all key indicator sites in March. The majority of sites recorded flows within the normal range or lower for the time of year. Groundwater levels across the KSLES area continued to rise at the majority of indicator sites during March, with the exception of Riverhead and Wolverton. Levels across all sites ranged from normal to notably high and remained in the same classification as reported last month.

2. Rainfall

During March, the KSLES area received an average rainfall total of 22mm, which was 51% of the LTA. Rainfall was predominantly below normal across the area, with notably low rainfall recorded in eastern catchments. Further in the west, rainfall remains within the normal range for the North Downs, South London, the Lower Mole and Upper Mole catchments. Conditions were driest in the east, with LTA rainfall ranging from 37% in the Thanet Chalk catchment to 72% in the Upper Mole catchment in the west. Rainfall amounts across the area varied throughout the month in March. There was only one dry day which recorded rainfall less than 0.2mm on 5 March. Despite this there were several days recording negligible rainfall (less than 1 mm), with a small number of intense rainfall events.

Over the last 3 months, rainfall was predominantly notably high to exceptionally high across the area. In the last 6 months, rainfall was generally above normal, with notably high totals in the south. Over the last 12 months, rainfall has been mostly normal across the area, with some catchments recording above normal rainfall.

3. Soil moisture deficit and recharge

SMDs across the KSLES area has increased from nearly zero in February to 24mm in March. This reflects the notably low rainfall experienced throughout the month. Effective rainfall recorded in March was only 22% of the LTA. As a result, soils began to dry, indicating a reduction in SMD following the period of winter recharge.

4. River flows

Monthly mean river flows decreased at all key indicator sites in March. The majority of sites recorded flows within the normal range or lower for the time of year. Below normal flows were recorded at the River Teise at Stonebridge; while the River Ravensbourne at Catford recorded notably low flows. In contrast, the River Dour at Crabble Mill (Chalk) recorded above normal flows for the time of year.

5. Groundwater levels   

Groundwater levels across the KSLES area continued to rise at the majority of indicator sites during March, though at a slower rate than February, with the exception of Riverhead and Wolverton where levels started to fall. Levels across all sites ranged from normal to notably high and remained in the same classification as reported last month. Groundwater levels in the Chalk aquifer sites at Chipstead, Sweeps Lane, Riddles Lane and Fleete Reservoir remained within the normal range. In the southeast of the area, Little Bucket recorded above normal groundwater levels, while Wolverton recorded notably high levels. In the Lower Greensand aquifer, levels at Riverhead remained in the above normal range.

6. Reservoir stocks

Out of 5 water company reservoirs in KSLES Bewl saw a rise in levels while levels at Darwell decreases during March. The remaining reservoir levels stayed stable throughout the month.

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

• Bewl – 99% normal
• Darwell – 92% below normal
• Bough Beech – 100% notably high
• Powdermill – 100% above normal
• Weir Wood – 100% above normal 

7. Environmental impact 

There were 28 fluvial flood alerts and 10 fluvial flood warnings issued in March. A groundwater flood alert was updated each week in March.

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.