Research and analysis

Kent and South London water situation: June 2026 summary

Updated 14 July 2026

Applies to England

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

The Kent, South London and East Sussex (KSLES) area received 143% of the long term average (LTA) rainfall in June, with effective rainfall reaching 109% of the LTA. Rainfall was above normal across the area. Soil moisture deficits (SMDs) increased to 125mm during June. Monthly mean river flows (MMFs) at key flow indicator sites either stayed the same, or increased from May records. River flows were normal for the majority of the area, with 3 sites registering below normal. Groundwater levels across KSLES continued to decline at all indicator sites, with Chipstead now falling within the below-normal range. Reservoir storage levels also decreased during June, ranging from exceptionally low to notably high.

1. Rainfall

During June, the KSLES area received 71mm, 143% of the LTA rainfall for the time of year, based on a whole-area average. All catchments in KSLES area received above normal rainfall. The percentage of LTA rainfall received ranged from 161% in the Sheppey catchment in the north of the area, to 125% in the Eastern Rother catchment in the south. The highest daily rainfall total of 35.6mm was observed on 22 June at Beckenham College rain gauge in the South London area. June 2026 was the wettest June since 2021. 

In June, the top 5 highest rainfall days were 22, 1, 10, 2, and 3 June. There were 3 dry days in June that recorded rainfall less than 0.2mm. The start of the month saw sustained showers until day 12. The middle and end of the month were predominantly dry, however peak daily rainfall occurred on day 22. Storms on this day brought an average of 12.4mm across all KSLES rain gauges.

2. Soil moisture deficit and recharge

SMDs across the KSLES area increased during June, recording a cross-area deficit of 125mm, 40mm higher than the LTA of 85mm. Although effective rainfall was 109% during the month, rainfall mainly occurred in the initial 11 days. A relatively dry period from 12 June saw the area receive an average of under 0.2mm rainfall for 14 of 19 days. A heatwave also occurred late in the month, with provisional temperatures reaching above 35 degrees Celsius. Combining record temperatures during June’s heatwave, with dry prior months of April and May, soil moisture loss continued.

3. River flows

MMFs across the catchment were mostly normal, with 3 sites in southern areas recording below normal flows. Below normal flows were observed in the Eden at Vexour/Penshurst, the East Stour at South Willesborough and the Rother at Udiam. This pattern reflects both geology and rainfall. Reduced flows were found in southern clay catchments that received between 125% and 139% of LTA rainfall. Comparatively the rest of KSLES area received between 132% and 161% of LTA rainfall.

4. Groundwater levels   

Groundwater levels across the KSLES area have continued to fall steadily at all 7 groundwater level sites. Levels across the catchment were mostly normal with the exception of Chipstead, which is now recording below normal. Groundwater levels in the Chalk aquifer sites at all other sites are now in normal range. This includes Little Bucket which previously recorded levels falling within the above-normal category. In the Lower Greensand aquifer, levels at Riverhead remained in the normal range. The fall in groundwater levels is consistent with the lack of effective rainfall over the last 3-month period and the SMDs registered by the end of June.

5. Reservoir stocks

Levels across all 5 reservoirs fell during June and range from notably high to exceptionally low. By the end of June, the reservoirs held the following live storage capacities and LTA class:

• Weir Wood – 96% notably high
• Bough Beech – 81% normal
• Bewl – 81% normal
• Darwell – 61% notably low
• Powdermill – 41% exceptionally low

Weir Wood reservoir remains offline.

6. Environmental impact 

Hands-off flow (HoF) restrictions remained in place for abstractors across the Medway and Stour catchments throughout June, having been implemented during March and April. In the Rother catchment, HoF restrictions were introduced for several abstractors in mid-June and persisted until month end.

There was one fluvial flooding alert issued during June for the Shuttle and Cray area, this was removed the next day. There were no groundwater flooding alerts or warnings issued in June.

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.