Research and analysis

Devon and Cornwall water situation: March 2026 summary

Updated 14 April 2026

Applies to England

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

1. Summary

Devon and Cornwall received 61mm of rain during March (68% of the March long term average, LTA), which is normal for the time of year. Soil moisture deficit (SMD) was higher (drier) than the LTA for March. Monthly mean river flows were normal to above normal for the time of year across the area. Groundwater levels ended the month between normal and exceptionally high for the time of year. Total reservoir storage across Devon and Cornwall on 29 March was 97%, with Wimbleball, Colliford and Roadford at 99%, 92% and 100% respectively.

2. Rainfall

Devon and Cornwall received 61mm of rain during March (68% of the March LTA), which is normal for the time of year. The month has been fairly settled, with the wettest spell between 10 and 12 March. This was the first month with below average rainfall since October 2025, although it was still the sixth wettest October (start of water year) to March in a record starting 1871.

All hydrological areas reported normal rainfall for the time of year, except the Exe, and Teign and Torbay hydrological areas, which reported below normal rainfall for the time of year.

Cumulative rainfall for the last 3 months was exceptionally high across the area except for the Taw and North Devon Streams, and Torridge and Hartland Streams hydrological areas, which experienced notably high rainfall. Over the last 6 months, rainfall was exceptionally high across the area except for Taw and North Devon Streams hydrological area, which recorded notably high rainfall. Over the last 12 months, rainfall was notably high to exceptionally high across Devon, with all hydrological areas in Cornwall experiencing exceptionally high rainfall.

3. Soil moisture deficit

SMD in the Devon and Cornwall area increased (became drier) from the middle of March in response to the drier weather. At the end of the month, most of the area recorded SMD between 11mm and 40mm, with hydrological areas in north Devon and north Cornwall recording SMD below 10mm. Eastern and western parts of the area recorded a difference of 6 to 25mm from the LTA for March. The rest of the area saw a difference within 5mm of the LTA.

4. River flows

March monthly mean river flows were normal across Devon and eastern Cornwall, with above normal flows recorded in western Cornwall.

All sites recorded an overall decrease to daily mean flows through March, from between above normal and exceptionally high at the start of the month to between normal and below normal at the end. There was a slight rise to a small peak mid-month in response to rainfall in the second week. Daily mean flows on 31 March were normal across Devon and Cornwall, except for the River Taw at Umberleigh, which recorded below normal flows.

Due to data accuracy concerns, Chudleigh Bridge on the River Teign, Thorverton on the River Exe, and Restormel on the River Fowey have not been reported on this month.

5. Groundwater levels   

On 31 March, groundwater levels were classed as:

• normal at Winnards Perch (monitoring the Staddon Formation)
• above normal at Coleford Production (monitoring the Permian Breccias and Sandstones)
• notably high at Woodleys No1 (monitoring the Otterton Sandstone Formation), Bussels No7A (monitoring the Dawlish sandstone) and Branscombe Lane (monitoring the Dawlish Sandstone)
• exceptionally high at Woodbury Common No2 (monitoring the Budleigh Salterton Pebble Beds), and Whitlands (monitoring the Upper Greensand)

Groundwater levels at all sites have reached their seasonal peaks and most are now in recession. Winnards Perch’s hydrograph is ‘noisy’, as levels at this site respond quickly to rainfall variations due to the low storage of the secondary aquifer which it monitors.

6. Reservoir stocks

Total reservoir storage was 97% on 29 March, which is an overall increase of 1% since the end of February. This is higher than storage at the end of March 2022 (the most recent drought year), which was 94%. On 29 March, storage at Wimbleball, Colliford and Roadford was 99%, 92% and 100% respectively, compared to 100%, 80% and 98% at the same time in 2022.

Author: Devon and Cornwall Hydrology, hydrology.dandc@environment-agency.gov.uk

All data are provisional and maybe subject to revision. The views expressed in this document are not necessarily the views of the Environment Agency. Its officers, servants, or agents accept no liability for loss or damage arising from the interpretation or use of the information, or reliance upon views contained in this report.