Research and analysis

Devon and Cornwall water situation: October 2025 summary

Updated 12 November 2025

Applies to England

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

1. Summary

Devon and Cornwall received 89% of the October long term average (LTA) rainfall, which was normal for the time of year. Soil moisture deficit (SMD) decreased overall during October. Monthly mean river flows were normal to below 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 by 2 November was 52%, with Wimbleball, Colliford and Roadford at 27%, 44% and 62% respectively.

2. Rainfall

Devon and Cornwall received 122mm of rain during October (89% of the October LTA), which is normal for the time of year. October was very dry for the first half of the month, with nearly 80% of the month’s rain falling between 18 to 31 October.

Cumulative rainfall for the last 3 months was normal across the area, with the exception of the Tamar hydrological area, which was above normal. Over the last 6 and 12 months, cumulative rainfall was normal across Devon and Cornwall, except the Otter, Sid, Axe and Lim and the Exe hydrological areas, where it was below normal.

3. Soil moisture deficit

SMD remained stable during the first half of October. In response to the rainfall from 18 October onwards, SMD decreased (got wetter) significantly, ending the month almost level with the LTA for the time of year and higher (drier) than the SMD at the same time in 2024.

The average deficit at the end of October was below 10mm across central areas of Devon and Cornwall. Eastern and western areas were drier, with the Exe, North Cornwall, Fal and St Austell and West Cornwall hydrological areas recording a deficit of between 11 and 40mm. The highest average deficit was in the Otter, Sid, Axe and Lim hydrological area, which was between 41 and 70mm.

SMD was 6 to 25mm higher (drier) than the long term average deficit for October in the Otter, Sid, Axe and Lim hydrological area. In the Tamar, Torridge and Hartland Streams, and Taw and North Devon Streams hydrological areas, SMD was between 6 and 25mm lower (wetter) than the LTA for October. All other hydrological areas ranged from a 5mm lower (wetter) to 5mm higher (drier) than the LTA for October.

4. River flows

October monthly mean river flows were normal at most sites across Devon and Cornwall, except for Chudleigh Bridge on the River Teign, which recorded below normal river flows for the month.

All sites experienced a decrease in daily mean river flows during the first half of October in response to the dry period, recording normal or below normal flows for the time of year. During the second half of the month, all sites recorded a significant increase in flows in response to rainfall, reaching between above normal and exceptionally high before dropping again in the final week of the month. Flows on 31 October were normal for all reporting sites except Gunnislake on the River Tamar and Bellever on the River Dart, which recorded above normal flows.

5. Groundwater levels   

On 31 October, groundwater levels were classed as follows:

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

Groundwater levels at most sites continue to be in recession, except for Winnards Perch, whose hydrograph is now on its rising limb. Levels at this site respond quickly to rainfall due to the low storage of the Secondary Aquifer which it monitors.

6. Reservoir stocks

Total reservoir storage was 52% on 2 November, which is an overall increase of 1% since the end of September. This is higher than storage at the same time in 2022 (the most recent drought year), which was 30%. On 2 November, storage at Wimbleball, Colliford and Roadford was 27%, 44% and 62% respectively, compared to 18%, 15% and 34% 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. he 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.