Research and analysis

Kent and South London water situation: July 2024 summary

Updated 14 August 2024

Applies to England

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

1. Summary

The whole of the Kent and South London (KSL) area received 119% of the long-term average (LTA) rainfall during July. Rainfall received across catchments in the area ranged from normal to above normal. Soil moisture deficits (SMDs) within all rainfall areas in KSL increased slightly throughout the month of July. The key flow sites ranged from normal to exceptionally high MMFs during July. Groundwater levels in the Chalk in July 2024 ranged from exceptionally high to above normal for this time of the year. Groundwater levels continue to fall consistently across Kent and South London aquifers. Levels in 4 out of 5 reservoirs in KSL decreased in July. 

2. Rainfall

The whole of the KSL area received slightly above average rainfall with 119% of the LTA during July. Rainfall received across catchments in the area ranged from normal to above normal. The above normal rainfall was received in the Medway and Upper Mole areas. The percentage of LTA rainfall received across catchments ranged from 81% across Thanet Chalk rainfall area to 163% in the Lower Mole. The highest daily rainfall total of 33.0mm for July was recorded at Hockers Lane PS RG in the North Kent Chalk catchment on the 15 July. The next highest daily rainfall totals were on 5, 7, 9 and 13 July and ranged from 17.8mm to 28.6mm. In July, there was only one day where less than 0.2mm of rainfall fell, this was the 19 July. 

3. Soil moisture deficit and recharge

Soil moisture deficits (SMDs) continue to fall as expected for this time of year. SMDs within all rainfall areas in KSL increased slightly throughout the month of July compared to June. At the end of the month SMDs were, on average, slightly higher than the end of month LTA. This is in line with the average and higher-than-average rainfall totals observed during July. The whole KSL area received 71% of the LTA effective rainfall in July, which resulted in the only slight increase in soil moisture deficits seen in July.

4. River flows

In July the MMFs ranged from normal to exceptionally high. Exceptionally high flows were observed at the River Dour at Crabble in the east, the Teise at Stonebridge and the Darent at Hawley which had the highest percentage LTA of 210%. Above normal flows were seen at the Stour at Horton, the Medway at Teston, Eden at Vexhour, Wandle at Connollys Mill and the Mole at Dorking. Flows were normal in the Rother at Udiam, East Stour at South Willesborough and the Ravensbourne at Catford which had the lowest percentage LTA of 77%. Many sites experienced exceptionally high peaks in response to rainfall at the beginning of the month, as the daily mean charts show.

5. Groundwater levels        

Groundwater levels ranged from exceptionally high to above normal across the KSL area. Many of the groundwater sites recorded notably high levels of groundwater for July. While Chipstead in the west of the catchment recorded above normal levels and Wolverton in the east saw exceptionally high levels reaching 40.02 mAOD, which is the highest water level recorded at Wolverton in July since records began in 1971. Although levels in the Chalk remain exceptionally high in the east of the patch, and notably high in most of the west, levels continue to fall consistently across the area. This also applies to groundwater levels in the Greensand aquifer at Riverhead.

6. Reservoir stocks

At the end of July, reservoir levels were:

• normal at Bewl at 82%, and Powdermill at 72%
• notably high at Weir Wood at 97%, Darwell at 83% and Bough Beech at 80%

Levels in 4 reservoirs in KSL decreased in July, although levels at Weir Wood slightly increased as this reservoir is currently offline.

7. Environmental impact 

Hands off flow constraints continue to apply to certain licensed abstractions within the Upper Stour and Medway catchments. 

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

Contact Details: 03708506506

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.