Research and analysis

Wessex water situation: June 2026 summary

Updated 14 July 2026

Applies to England

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

The dry weather was briefly interrupted in June 2026, with an average of 79mm of rain falling across Wessex, 132% of the long term average (LTA). The majority of days in June were dry with most rain falling during the first 10 days of the month. Over the last 3 months, Wessex has still only received 76% of the LTA rainfall. Soil moisture deficit (SMD) initially fell during the first week of June in response to the rain, before rising for the remainder of the month. At the end of June, SMD was similar to the same time last year. River flows peaked early in June in response to the rain. Monthly mean flows were predominantly normal across Wessex with some sites to the west and in the Hampshire Avon catchment recording below normal flows. Groundwater levels also fell during June. At the end of the month, most sites monitoring the Wessex Basin Chalk reported below normal levels while most sites monitoring other geologies in the north and west reported normal levels. The 2 sites which reported notably low levels at the end of June were Woodyates (monitoring the Wessex Basin Chalk) and Chipley (monitoring the Otter Sandstone). At the end of June, reservoirs storage for Wessex Water and Bristol Water were at approximately 73% and 79% capacity respectively.

1. Rainfall

An average of 79mm of rain fell across Wessex in June, 132% of the LTA. It was a wet start to the month with 82% of the total monthly rain falling between 1 and 10 June. The remainder of the month was largely dry. The largest rainfall event occurred on 1 June when 28% of the total monthly rain fell. Rainfall was mostly higher in the north of Wessex than the south. Most hydrological areas recorded normal or above normal rainfall except for 3 catchments in the north which recorded notably high rainfall. The highest total monthly rainfall was recorded in the Mendips and River Chew area with an average of 113mm, 173% of the LTA. The lowest total monthly rainfall was reported in the Tone catchment with 63mm, 99% of the LTA.

Despite the wet start to June, the last 3-month period (April to June) has been drier than average across Wessex with 76% of the LTA. Over the last 3 months, rainfall was normal in the north of Wessex and below normal across the south and west. The Upper Hampshire Avon and Bourne catchments to the east of Wessex were the only areas to record notably low rain over the past 3 months. Over the past 6 months, most hydrological areas have recorded notably to exceptionally high rainfall except for 3 areas to the north and west which only recorded above normal. In the last 12 months, most areas to the north recorded above normal rainfall while most areas to the south recorded notably high rainfall.

2. Soil moisture

SMD fell for the first week of June in response to the high rainfall. After the weather became drier, SMD rose for the remainder of the month. At the end of June, SMD was close to the deficit this time last year and not far from the historic maximum. At the end of the month, most hydrological areas in Wessex had SMD levels between 101mm and 130mm with some areas to the south east recording levels between 131mm and 160mm. At the end of June, SMD was 26 to 50mm greater than the LTA in the north and 51mm to 75mm greater than the LTA in the south.

3. River flows

Daily mean river flows peaked at the start of June in response to the heavy rainfall and mostly fell for the remainder of the month. Some sites in the north of Wessex also recorded a brief peak in daily mean flows following rain on 22 June. At the end of the month, daily mean flows tended to be lower in catchments in the south on the Wessex Basin Chalk than in the north. All reporting sites in Wessex reported monthly mean flows below the LTA except for the Asker at Bridport East Bridge which reported monthly mean flows of 111% of the LTA. Most sites reported flows within the normal banding. The exceptions were the Hampshire Avon at Amesbury and East Mills Combined and the Wylye at South Newton to the east and the Tone at Bishops Hull and the Washford at Beggearn Huish in the west which all reported below normal monthly mean flows.

4. Groundwater levels   

Groundwater levels continued to fall across all of Wessex in June despite the rain early in the month. At the end of June, the majority of monitoring sites on the Wessex Basin Chalk reported below normal levels. The 2 exceptions were Delcombe which reported normal levels and Woodyates which reported notably low levels. Amongst the 5 sites monitoring other geologies, 3 reported normal levels. Chipley (monitoring the Otter Sandstone) to the west reported notably low levels while Allington (monitoring the Great Oolite) to the north reported below normal levels.

5. Reservoir storage

Reservoir storage has fallen through June for both Bristol Water and Wessex Water. Wessex Water ended the month at approximately 73% capacity, similar to last year and slightly higher than in 1995. Bristol Water ended June at approximately 79% capacity, higher than in 2025 and similar to in 1995.

Author: Wessex Hydrology, hydrologywessex@environment-agency.gov.uk

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.