Kent and South London water situation: July 2026 summary
Updated 12 August 2026
Applies to England
© Crown copyright 2026
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1. Summary
The Kent, South London and East Sussex (KSLES) area recorded 1% of the long-term average (LTA) rainfall for July. Soil moisture deficits (SMDs) continued to increase across KSLES and stretched further from the LTA. Monthly mean river flows (MMFs) decreased across all key flow indicator sites except for the Teise at Stonebridge (normal) and the Dour at Crabble (normal). Four sites recorded flows within the exceptionally low class. Groundwater levels across KSLES continued to decline, with Fleete Reservoir, Chipstead and Sweeps Lane now falling within the below normal class. Reservoir storage levels also decreased during July, ranging from exceptionally low to above normal.
2. Rainfall
July has been a dry month with all hydrological areas in KSLES recording exceptionally low rainfall (1% of the LTA). The maximum rainfall received was 3% in the Upper Mole. The highest daily rainfall total of 2.8mm was observed on 30 July at Hartley PS rain gauge in the Darent hydrological area. July 2026 was the driest July on record (since record began in 1871). In addition, from April to July 2026 was the fourth driest on record.
3. Soil moisture deficit and recharge
Due to the continued lack of rainfall and high temperatures, SMD increased across KSLES during July. This summer period (from 1 April to end of July), KSLES has received only 51% of the LTA rainfall, creating a large SMD. By month end KSLES had a SMD of 168mm, increasing from 125mm in June. The SMD in KSLES is now 64mm higher than the LTA (104mm), meaning it is significantly drier than expected for the time of year. The south-west of the area has the largest difference from LTA with 4 regions greater than 75mm. The majority of the area is yet to receive any effective rainfall this summer period.
4. River flows
The continued lack of rainfall that has led to drier soils is beginning to influence river flows in most of the hydrological areas. River flows decreased at all of our indicator sites with MMFs ranging from normal to exceptionally low during July. Exceptionally low flows have been recorded in flashy rivers that are highly responsive to rainfall. The River Eden at Vexour/Penshurst, the River Mole at Dorking, and the River Ravensbourne at Catford each recorded their lowest July MMF since records began at those gauging stations. This pattern reflects the geology of the region as all are found in catchments with lower groundwater baseflow support. Normal flows were seen in the Dour at Crabble and the Teise at Stonebridge. The Dour continued to benefit from groundwater contributions from the Dover Chalk aquifer. Flows in the Teise at Stonebridge are supported by releases from Bewl reservoir, which feeds into the Medway. Other chalk and Lower Greensand aquifer supported rivers, the Darent at Hawley, the Stour at Horton, and the Wandle at Crabble recorded below normal flows during July.
5. Groundwater levels
Groundwater levels continued to decline seasonally across KSLES. The decline is consistent with the expected seasonal pattern. However, the rate of recession has been more pronounced, reflecting the lack of rainfall over the last 6-month period and the SMDs registered. Most groundwater sites (4) remain in the normal class, however groundwater levels in the chalk aquifer sites vary. Western sites of Chipstead and Sweeps Lane fall within the below normal class for this period, whilst in the east, Fleete Reservoir is the only site currently recording levels below the normal category. Eastern sites of Little Bucket, Riddles Lane and Wolverton are normal. Despite continued seasonal reduction in levels within the Lower Greensand aquifer, levels at Riverhead remained in the normal class for this time of year.
6. Reservoir stocks
With no rainfall recharge and continued high temperatures, storage across all 5 reservoirs fell during July. By the end of July, the reservoirs held the following live storage capacities and banding categories:
- Bewl – 68% normal
- Bough Beech – 68% normal
- Darwell – 53% below normal
- Powdermill – 33% exceptionally low
- Weir Wood – 90% above normal
Weir Wood reservoir remains offline.
6.1 Environmental impact
Hands-off flow (HoF) restrictions remained widespread throughout July across the Medway, Stour and Rother catchments. Restrictions introduced in the Medway and Stour catchments during March and April, and in the Rother catchment during mid-June, persisted throughout the month. A handful of additional HoF restrictions were triggered during the first half of July across the Stour, Darent and North Kent catchments.
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 herein.