Research and analysis

Thames water situation: February 2026 summary

Updated 12 March 2026

Applies to England

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

1. Summary

Thames area received 108mm of rainfall in February, which was 199% of the long term average (LTA). It was the third wettest February in Cotswolds East. Soil moisture deficits (SMD) were negligible in all areal units by the end of the month. Saturated soils allowed significant effective rainfall to occur, with 248% of the LTA for the area. Monthly mean river flows increased at 14 of our indicator sites in February. Seven of our sites were exceptionally high, while 7 were notably high. The rivers Cherwell at Banbury and Wey at Tilford recorded their second highest February flows on record. Groundwater levels increased at the majority of our indicator sites in February in response to the above average recharge. Five sites were exceptionally high. Farmoor reservoir was above average while the Lower Thames reservoirs were below average for the time of year. In February, a total of 22 fluvial alerts, 6 groundwater alerts, and 8 flood warnings were issued.

2. Rainfall

Thames area received 108mm of rainfall in February, which was 199% of the LTA. Exceptionally high rain fell across the 3 northernmost rainfall units (Cotswolds West, Cotswolds East, and Cherwell). Cotswolds East received over two and a half times the LTA for February, the third wettest since 1871. The remaining areal units received notably high rainfall, apart from Wey Greensand, which was above normal. Over the past 3 months, all areal units received exceptionally high rainfall.

3. Soil moisture deficit and recharge

SMDs were negligible in all areal units by the end of the month which meant they were wetter than usual. Saturated soils allowed significant effective rainfall to occur, 248% of the LTA at the end of the month.

4. River flows

Monthly mean river flows increased at 14 of our indicator sites in February. Seven of our sites were exceptionally high while 7 were notably high. The river Cherwell at Banbury recorded 325% of its LTA average monthly flow, the second highest February on record, behind only 2024. The river Wey at Tilford also recorded its second highest February flow, behind only 2014.

5. Groundwater levels   

Groundwater levels increased at most of our indicator sites in February in response to the above average rainfall. All sites are within the above normal to exceptionally high range.

Groundwater levels were exceptionally high at:

• Ampney Crucis (great oolite)
• Fringford (great oolite)
• Marcham (corallian)

• Rockley (chalk)

• The Flashes (lower greensand)

Groundwater levels were notably high at:

• Gibbet Cottages (chalk)
• Long Sutton (chalk)
• Frith Cottage (lower greensand)
• Model Farm (upper greensand)

Groundwater levels were above normal at:

• Jackaments Bottom (inferior oolite)
• Stonor (chalk)

6. Reservoir stocks

Reservoir stocks in Farmoor increased from 80.4% to 98.7%, while the Lower Thames reservoirs increased from 88.6% to 90%. Farmoor reservoir was above average while the Lower Thames reservoirs were below average for the time of year.

7. Environmental impact

In February, a total of 22 fluvial alerts, 6 groundwater alerts, and 8 flood warnings were issued for rivers across the Thames area. At the end of February, no abstraction licences were being constrained in the area to protect water resources. 

Author: Thames Area Groundwater Resources and Hydrology, enquiriesWT@environment-agency.gov.uk

Contact Details: 030708 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.