Kent and South London water situation: February 2025 summary
Updated 12 March 2025
Applies to England
© Crown copyright 2025
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1. Summary
The whole of the Kent and South London area received 116% of the long term average (LTA) rainfall during February. Rainfall received was normal across all catchments. At the end of February, soil moisture deficits (SMD) were below 10mm in all catchments, except for the Thanet Chalk in the northeast of Kent and South London. On average, effective rainfall received this month was at 126% of the LTA. Monthly mean flows ranged from normal to above normal in February in Kent and south London. Three out of the eleven key flow sites saw above normal Monthly mean flows. Groundwater levels in the Chalk continued to increase at the expected rates across the Kent and South London area and are predominantly normal for this time of year. The Lower Greensand aquifer at Riverhead continued to register groundwater levels that are notably high. Levels at the end of the month at the five water company reservoirs in the area ranged from below normal to above average.
2. Rainfall
The whole of the Kent and South London (KSL) area received 116% of the LTA rainfall during February. Rainfall received was normal across all catchments. The percentage of LTA rainfall received ranged from 135% across Lower Mole rainfall area to 96% in the Sheppey rainfall area. In the previous 3 months, spanning from December to February, normal rainfall was recorded across all catchments. In the previous 6 months, from August to February, rainfall was normal in across catchments in the northeast of the patch. Medway and Lower Mole rainfall areas saw notably high rainfall, whilst all other rainfall areas in the south and west received above normal rainfall. In the last 12 months, rainfall ranged from notably high to normal in KSL area. Notably high and above normal rainfall were recorded in catchments in the south and west, whilst normal was recorded in catchments in in the northeast of the area. The highest daily rainfall total of 23mm for February was recorded at Eden Vale STW rain gauge in the Medway catchment on 23 February. The next highest daily rainfall totals were on 21, 26, 7 and 9 February and ranged from 19.4mm to 10.5mm. In the month of February, the rainfall received was concentrated at the begging and the end of the month with a dryer period in the middle. There were no dry days where rainfall received was less than 0.2mm in February.
3. Soil moisture deficit and recharge
At the end of February, SMD throughout all rainfall areas were minimal, with the majority of these being close to 0mm. The SMD for the whole KSL area was 2mm. This is slightly less than the LTA for this time of year, which is 8mm. SMDs increased slightly in most catchments in February due to the very slight decrease in the effective rainfall received compared to January. Across the whole area, on average, effective rainfall received this month was 126% of the LTA.
4. River flows
Monthly mean flows (MMFs) ranged from normal to above normal in February in KSL. The River Wandle at Conolly’s Mill, the River Mole at Dorking in the northwest, and River Medway at Teston in the centre of the patch saw above normal flows. Three out of the eleven key flow sites saw above normal MMFs. River Medway at Teston recorded the highest MMF highest percentage LTA of 124% for the month of February. River Ravensbourne at Catford recorded the lowest percentage LTA of 76%.
5. Groundwater levels
Groundwater levels in the Chalk are remaining predominantly normal for this time of year at the end of February. Only levels at Riddles Lane are still being registered as above normal in the chalk. The Lower Greensand aquifer at Riverhead continued to register groundwater levels that are notably high. Groundwater levels in the Chalk continued to increase at the expected rates across the KSL area, except at Fleete Reservoir (Thanet) where the rise has levelled out in response to lower effective rainfall there. Elsewhere, the rise in groundwater levels is consistent with the effective rainfall of 126% of the LTA and the SMDs registered by the end of February. Like January, the rate of rise was steadied by the drier spell in the middle of the month.
6. Reservoir stocks
At the end of February, reservoir levels were:
- below normal at Darwell at 80%
- normal at Bough Beech with 94% and Bewl at 88%
- above normal at Weir Wood and Powdermill reservoirs as they were full at the end of this month
Weir Wood reservoir remained offline during February.
7. Environmental impact
Nine fluvial flood alerts were issued in February.
Author: Groundwater and Hydrology Team, ksl.gwh@environment-agency.gov.uk
Contact Details: 03708 506 507
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.