Research and analysis

Water situation: July 2024 summary

Updated 12 December 2024

Applies to England

It has been a wetter month across England with most catchments receiving above average rainfall during July. Soil moisture deficits (SMD) have increased across England, with many parts of the country ending July with drier soils than at the start of the month. River flows decreased at nearly two-thirds of indicator sites in July and were classed as normal or higher at all sites. Groundwater levels decreased at all but 2 of the sites we report on and levels at more than half of sites remain classed as notably or exceptionally high for the time of year. Reservoir storage decreased at more than four-fifths of the reservoirs we report on and the majority of reservoirs were classed as normal or higher. Reservoir stocks across England were 84% full at the end of July.

1. Rainfall

The rainfall total for England for July was 79mm which represents 136% of the 1961 to 1990 long term average (LTA) for the month (119% of the 1991 to 2020 LTA). Most catchments received above average rainfall during July with only 10 catchments receiving below average rainfall. The wettest hydrological area relative to the LTA was the West Dorset Streams catchment in south-west England which received 221% of LTA rainfall. The driest hydrological areas was the Ribble catchment in north-west England which received 80% of LTA rainfall in July.

July rainfall totals were classed as normal or higher for the time of year in all catchments in England. Eighty-three catchments (60%) were classed as normal for the time of year. At the regional scale, rainfall totals were classed as normal for all areas of England and England as a whole.

The 3-month cumulative totals were above normal or higher across all but 2 catchments in England with nearly three-quarters of catchments classed as normal. The last 6 months have also seen exceptionally high or notably high cumulative totals at all but 1 catchment across country and it has been the wettest 6 month period ending in July since 1871 for 31 catchments. It has also been the wettest 6 month period for south-west England since 1871. The 12-month cumulative totals were exceptionally high in all but 5 catchments and it has been the wettest 12 months ending in July since 1871 for 65 catchments. It has also been the wettest 12 month period until July for England as a whole since 1871. Furthermore, north-west, north-east and south-west England all recorded the wettest 12 month period ending in July since 1871.

2. Soil moisture deficit

Despite above average rainfall soil moisture deficits (SMD) increased slightly across most of England. SMDs throughout England reduced through mid-July however the warmer temperatures towards the end of the July resulted in increases in SMD.

At a regional scale, soils across all areas of England with the exception of the south-east remain wetter than average for the time of year. SMDs in south-east England are around average for the time of year. Across all regions of England soil moisture deficits increased and soils were drier at the end of July than they were at the end of June.

3. River flows

Monthly mean river flows decreased at nearly two-thirds of indicator sites in July however monthly mean flows remain classed as normal or higher at all sites. Sixteen sites (29% of the total) were classed as normal for the time of year. Twenty sites (36% of the total) were classed as above normal for the time of year and 12 sites (22%) were classed as notably high. Seven sites (13%) were exceptionally high and 1 site, Hansteads, on the River Ver, recorded its highest monthly mean flow for July on record (since 1956).

Four regional index sites saw a decrease in monthly mean flows in July. Naturalised flows at Kingston on the River Thames and Orford on the Bedford Ouse were classed as notably high for the time of year. The Great Stour in south-east England, the River Dove in central England and the South Tyne in the north-east all recorded above normal monthly mean flows. River Exe in south-west England and the River Lune in the north-west recorded monthly mean flows which were in the normal range.

4. Groundwater levels   

At the end of July, all but 2 of the groundwater indicator sites we report on recorded a decrease in levels. At nearly a third of the indicator sites, groundwater levels were classed as exceptionally high, almost a quarter of sites were above normal and 8 sites were classed as notably high for the time of year. Four sites were classed as normal at the end of July.

Five sites recorded their highest end of July groundwater level on record including:

• Weir Farm (since 1983) in Bridgnorth Sandstone in central England
• Coxmoor (since 1990) in Idle Torne Sandstone in central England
• Aycliffe (since 1979) in Skerne Magnesian Limestone in the north-east
• Priors Heyes (since 1972) in West Cheshire Sandstone in the north-west
• Skirwith (since 1978) in Carlisle Basin Sandstone in the north-west

Groundwater levels decreased at all aquifer index sites in July. Weir Farm (Bridgnorth Sandstone), Skirwith (Carlisle Basin Sandstone) and Stonor Park (South West Chilterns Chalk) were all classed as exceptionally high for the time of year. Levels at Little Bucket (East Kent Stour Chalk) were notably high. Redlands Hall (Cam and Ely Ouse Chalk), Chilgrove (Chichester Chalk) and Dalton Estate (Hull and East Riding Chalk) were notably high. Jackaments Bottom (Burford Jurassic Limestone) in the south-east was above normal at the end of July.

5. Reservoir storage

Reservoir storage decreased during July at more than four-fifths of the reservoirs and reservoir groups we report on. The largest stock decreases were at Clatworthy and Wimbleball both in south-west England which decreased 16% and 14% respectively. All but 2 of reservoirs and reservoir groups we report on at the end of July were classed as normal or higher for the time of year. The Dee system, continues to be impacted by ongoing reservoir maintenance and was classed as below normal.

At a regional scale, total reservoir storage decreased in all regions. In south-west England, overall storage decreased by 9% during July. For England as whole, storage decreased to 84% at the end of July.

6. Forward look

August is likely to experience warmer than average temperatures, and drier than average weather, resulting in an increased chance of heatwaves across England. Despite the drier than average forecast, changeable conditions are predicted across the country, particularity in the north-east and north-west, with an increased chance for localised showers and thunderstorms. Towards the end of the month there is a chance of a settled period of drier, warmer weather, but forecasts remain uncertain.

For the 3 month period between August and October, there is a higher than expected chance of warmer, drier weather. These conditions have increased the likelihood of heatwaves, especially during the August to September period. Projections for river flows at key sites.

By the end of September 2024, river flows are projected to be above normal or higher in the east and south-east of England, where many rivers are supported by groundwater discharge from porous aquifers. Across the rest of England, river flows are projected to be normal.

By the end of March 2025, flow at almost all of the rivers across the country are projected to be normal or higher, with the greatest flows expected in the south-east, and east of England.

7. Projections for groundwater levels in key aquifers

By the end of September 2024, groundwater levels are projected to be above normal or higher across most of England as levels at many aquifers remain higher than expected following a wet winter and ongoing wet weather.

By the end of March 2025, groundwater levels are projected to be normal across most of England, with sites in the north-east of the country more likely to see below normal or lower groundwater levels.

Author: National Water Resources Hydrology Team, [email protected]

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.