Research and analysis

Devon and Cornwall water situation: March 2025 summary

Updated 14 April 2025

Applies to England

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

1. Summary

Devon and Cornwall received 14% of the March long term average (LTA) rainfall, which is exceptionally low for the time of year. Soil moisture deficit increased overall in March, ending the month higher (drier) than the LTA for the time of year. Monthly mean river flows were exceptionally low to normal for the time of year across the area. Groundwater levels were below normal to exceptionally high for the time of year. Total reservoir storage across Devon and Cornwall ended the month at 94%, with Wimbleball, Colliford and Roadford at 97%, 87% and 97% respectively at the end of March.

2. Rainfall

Devon and Cornwall received 14mm of rain during March (14% of the March LTA), which is classed as exceptionally low for the time of year. It was the 6th driest March on record in Devon and Cornwall and the driest March on record for the Teign and Torbay hydrological area, in a record starting 1871. Many other areas recorded a significantly dry March, including the Exe, Taw and North Devon Streams, Torridge and Hartland Streams and the Avon Dart and Erme hydrological areas recording the second driest March for those areas in a record starting 1871.

Rainfall was slightly higher in the west of the area, with West Cornwall and the Fal and St Austell hydrological areas recording below normal and notably low rainfall for the time of year respectively. Cumulative rainfall was normal across all hydrological areas in the last 3 and 6 months. In the last 12 months, cumulative rainfall ranged from normal to above normal across the area.

3. Soil moisture deficit

SMD increased overall in March in response to the dry weather. The average deficit for Devon and Cornwall was between 11mm and 40mm at the end of March across the whole area. The SMD at the end of March was higher (drier) than the SMD at the end of March 2024 and significantly higher (drier) than the LTA, close to the historic maximum for the time of year.

4. River flows

March monthly mean river flows ranged from exceptionally low to normal across the area.

Daily mean river flows decreased at all sites during the month of March in response to the lack of rainfall. On 31 March, all reporting sites recorded exceptionally low to below normal daily mean flows, except for Whitford on the River Axe, which recorded normal daily mean flows for the time of year.

Due to data accuracy concerns, Chudleigh Bridge on the River Teign has been excluded from the March report.

5. Groundwater levels   

On 31 March, groundwater levels were classed as follows:

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

6. Reservoir stocks

Total reservoir storage was 94% at the end of March, which was a decrease in storage of 2% since the end of February. This is less than the total storage at the same time last year and similar to the total storage at the time in 2022. At the end of the month, storage at Wimbleball, Colliford and Roadford was 97%, 87% and 97% respectively, compared to 100%, 98% and 100% this time last year.

Author: Environment Agency, 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.