Research and analysis

Devon and Cornwall water situation: July 2025 summary

Updated 12 August 2025

Applies to England

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

1. Summary

Devon and Cornwall received 58% of the July long term average (LTA) rainfall, which was below normal for the time of year. Soil moisture deficit increased overall in July. Monthly mean river flows were normal to notably high 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 ended the month at 69%, with Wimbleball, Colliford and Roadford at 58%, 62% and 80% respectively at the end of July.

2. Rainfall

Devon and Cornwall received 48mm of rain during July (58% of the July LTA), which is below normal for the time of year. Although rain fell every day in July, the most significant periods of rain occurred on 5, 15 and 19 to 21 July.

In July, rainfall was normal in Cornwall and mostly below normal in Devon, except for the Teign and Torbay and the Taw and North Devon Streams hydrological areas where cumulative rainfall was also normal for the time of year. Cumulative rainfall was mostly normal in the last 3 months across Devon and Cornwall, except for the Exe and West Cornwall where rainfall was below normal for the time of year and the Otter, Sid, Axe and Lim hydrological area where rainfall was notably low for the time of year. In the last 6 months, cumulative rainfall was normal in most hydrological areas, including all of Cornwall and West Devon. The 6-month cumulative rainfall was below normal for the time of year in the Taw and North Devon Streams and the Exe hydrological areas, and notably low for the time of year in the Otter, Sid, Axe and Lim hydrological area. In the last 12 months, cumulative rainfall was normal for the time of year across Devon and Cornwall.

3. Soil moisture deficit

SMD increased overall in July due to dry periods at the beginning and end of the month. It did however decrease in the middle of the month for a short period in response to the most significant period of rainfall. The SMD at the end of July was higher (drier) than the LTA for the time of year and higher (drier) than the SMD at the end of July 2024.  

The average deficit at the end of July for most of Devon and Cornwall was between 101 and 130mm, apart from the Tamar, Seaton, Looe and Fowey and Avon, Dart and Erme hydrological areas where the average deficit was between 71 and 100mm. The average deficit was highest in the Otter, Sid, Axe and Lim hydrological area recording a deficit of 131 and160mm.

SMD at the end of July was 26-50mm higher (drier) than the LTA for the time of year across most of Devon and Cornwall. In the Exe and the Otter, Sid, Axe and Lim hydrological areas SMD was 51 to 75mm higher (drier) than the LTA for the time of year.

4. River flows

July monthly mean river flows were normal at most sites, except for some sites in South and East Devon where monthly mean river flows were above normal and Whitford on the River Axe where the July mean monthly flow was exceptionally high.

Daily mean flows decreased at all sites during the last week of July, except for Lifton Park on the River Lyd, Torrington on the River Torridge and Woodleigh on the River Mole where daily mean flows increased by the end of the month. On 31 July, all reporting sites recorded notably low to normal daily mean flows for the time of year.

Due to data accuracy concerns, St Erth on the River Hayle has been excluded from the July report.

5. Groundwater levels   

On 31 July, groundwater levels were classed as follows:

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

Groundwater levels at all sites continue to be in recession, which is normal for the time of year.

6. Reservoir stocks

Total reservoir storage was 69% at the end of July, which is an overall decrease of 11% since the end of July. This is higher than storage at the same time in 2022 (the most recent drought year), which was 56%. At the end of July, storage at Wimbleball, Colliford and Roadford was 58%, 62% and 80% respectively, compared to 51%, 45% and 62% at the same time in 2022.

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.