Research and analysis

Kent and South London water situation: April 2026 summary

Updated 13 May 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 4mm in April, which was 10% of the long term average (LTA). Rainfall was predominantly exceptionally low in the area, with notably low rainfall recorded in one western catchment. Soil moisture deficits (SMDs) across the KSLES area increased to 79mm in April. Effective rainfall recorded in April was 0% of the LTA. Monthly mean river flows decreased at all key indicator sites in April. River flows varied across the area, ranging from exceptionally low to above normal. Groundwater levels across the KSLES started to decrease at all indicator sites during April. Levels across all 5 reservoirs decreased during April and ranged from notably low to normal.

2. Rainfall

During April, the KSLES area received 10% of the LTA rainfall for the time of year, based on a whole-area average. Rainfall received in the KSLES area ranged from exceptionally low in 13 out of 14 catchments to notably low in the Lower Mole. The percentage of LTA rainfall received ranged from 6% in the Darent catchment in the centre of the patch, to 15% in the Lower Mole catchment in the West. The highest daily rainfall total of 12.5mm was observed on day 13 of the month at Northfleet STW RG in the Darent. 

In April, the top 5 highest rainfall days were 13, 12, 18, 15, and 14 April. There were 14 dry days in April that recorded rainfall less than 0.2mm. The middle of the month saw small localised showers while the beginning and end of the month were predominantly dry. Overall, April was the sixth driest on record since records began in 1871.

3. Soil moisture deficit and recharge

SMDs across the KSLES area continued to increase during April, recording a deficit of 79mm, with the LTA being 40mm. This reflects the exceptionally low rainfall experienced throughout the month. Effective rainfall recorded in April was 0% of the LTA. While this indicates continued soil drying, increasing SMDs are typical for this time of year as soils naturally dry through spring. The higher deficit is largely attributable to an unusually dry April rather than a typical seasonal behaviour.

4. River flows

During April:

• exceptionally low river flows were recorded at the River Ravensbourne at Catford
• notably low flows were observed at the River Mole at Dorking, the River Eden at Vexour and Penshurst, and the River Teise at Stonebridge
• below normal flows were seen at the River Medway at Teston and in the East Stour at South Willesborough, both of which are situated in the Greensand aquifer
• normal flows were recorded at the River Wandle at Connolly’s Mill, the River Darent at Hawley, and the Stour at Horton
• above normal flows were observed at the River Dour at Crabble

The dry April and significantly low rainfall are reflected in the reduced flows within the clay and Greensand catchments, while flows in the chalk catchments at Crabble, Horton and Hawley remain supported by elevated base flow contributions from the underlying chalk geology.

5. Groundwater levels

Groundwater levels across the KSLES area are now falling at all 7 groundwater level sites. Riverhead and Wolverton began decreasing in March while the remaining sites started to fall in April. Levels across the catchment ranged from normal to above normal. Groundwater levels in the Chalk aquifer sites at Chipstead, Sweeps Lane, Riddles Lane and Fleete Reservoir remained normal, while Little Bucket and Wolverton in the Southeast recorded above normal groundwater levels. In the case of Wolverton, this represents a fall from notably high levels last month to an above normal range this month. In the Lower Greensand aquifer, levels at Riverhead are now in the normal range. The fall in groundwater levels is consistent with the lack of effective rainfall in March and April and the SMDs registered by the end of during April.

6. Reservoir stocks

In the month of April, all 5 reservoirs saw a decrease in water levels. By the end of April, the reservoirs held the following live storage capacities and LTA class:

• Bewl –97% normal
• Darwell –77% notably low
• Bough Beech – 97% normal
• Powdermill – 84% notably low
• Weir Wood – 99% normal

7. Environmental impact

Widespread hands-off flow restrictions were applied to abstractors in the Medway catchment during early April, with further hands‑off flow restrictions applied to some abstractors in the Wye catchment towards the end of April. There were no fluvial or groundwater flooding alerts or warnings issued during April. The East Kent groundwater flooding alert was removed on 10 April.

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.