Research and analysis

Water situation: October 2022 summary

Updated 11 January 2023

Applies to England

Monthly rainfall totals in October were above average in most of the catchments across England.

As a result of the rainfall, soil moisture deficits continued to decline across the country, however soils remain drier than would be expected in many places for the time of year.

River flows increased in October at the majority of indicator sites and most sites are now classed as normal for the time of year though a third of sites still remain below normal or lower.

Groundwater levels continued to decline at all but 3 indicator sites, and most remain below normal or lower for the time of year.

Reservoir stocks in October increased at the majority of reservoirs and reservoir groups we report on however end of month reservoir stocks remain below normal or lower at all but 2 sites.

1. Rainfall

The October rainfall total for England was 99.6mm which represents 130% of the 1961 to 1990 long term average (LTA) for the time of year (110% of the 1991 to 2020 LTA). The majority of catchments received above average rainfall during October, with the Witham to Chapel Hill catchment in east England being the wettest part of the country (relative to its LTA) having received 209% of October’s LTA rainfall. The Thanet Chalk catchment in south east England was the driest catchment (relative to its LTA) receiving 53% of LTA rainfall.

October rainfall totals were classed as normal for almost two-thirds of catchments across the country, with the other third being above normal or notably high. At a regional scale, October rainfall totals were normal in all regions, with the exception of north west and central England which were above normal. England as a whole was normal for the time of year.

England as a whole, has had the seventh driest 12 month period ending in October on record (using records since 1891) and the driest since 1988 to 1989, with south west England recording the third driest 12 month period ending October on record and the driest since 1933 to 1934.

2. Soil moisture deficit

Soil moisture deficits (SMD) continued to decline across the country during October. Soils became wetter in many areas due to above average rainfall and lower temperatures.

With the above average rainfall, the end of October SMDs were below (wetter than) average for the time of year across central and northern England. SMDs remained above (drier than) average for the time of year across southern England, particularly in the far east of the country. Soils in east and south east England continue to be drier than expected for the time of year.

3. River flows

October monthly mean river flows increased at more than four-fifths of the indicator sites we report on, compared to September. The majority of sites were classed as normal for the time of year however over a third of sites remain below normal or lower for the time of year.

At the regional index sites monthly mean flows show a varied picture at the end of October. Most index sites were classed as normal or below normal for the time of year. However monthly mean flows range from above normal at Haydon Bridge on the South Tyne in north east England to notably low at Thorverton on the Exe and at Horton on the Great Stour, in south west and south east England respectively.

4. Groundwater levels

At the end of October, groundwater levels decreased at all but 3 of the reported indicator sites. The majority of end of month groundwater levels were classed as normal or lower, with 4 sites exceptionally low for the time of year. Only 3 sites recorded end of month levels higher than would be typically expected for the time of year.

The major aquifer index sites were classed normal or lower for the end of October, with the exception of Skirwith in the Carlisle Basin Sandstone which was above normal for the time of year. End of month groundwater levels at Jackaments Bottom in the Burford Jurassic Limestone of the Cotswolds and Chilgrove in the West Sussex Chalk were classed as exceptionally low. Chilgrove has been classed as exceptionally low for the third consecutive month and has recorded the lowest end of October level on record (record goes back to 1836).

5. Reservoir storage

At the end of October reservoir stocks increased at most of the reservoirs and reservoir groups we report on. Eight reservoirs or reservoir groups saw an increase of 10% or more in their stocks in comparison to the end of September. Despite these increases, end of month reservoir stocks were classed as below normal or lower in all except 2 reservoirs and reservoir groups.

At a regional scale, total reservoirs stocks ranged from 27% in south west England to 68% in north east England. Total reservoir stocks for England were at 56% of total capacity at the end of October. For the south west and England these totals are the lowest on record for the end of October since records started in 1988.

6. Forward look

Early November was dominated by wet weather across most of the country, with periods of heavy rainfall. Temperatures have been mild, with windy conditions in many areas. Conditions are expected to be mixed through the middle of November, with spells of rain and strong winds in the north west and milder conditions elsewhere. Towards the end of November pressure is expected to build near the UK, bringing drier, cooler weather in many areas.

For the 3 month period from November to January there is a greater chance of cold and dry conditions than mild and wet.

7. Projections for river flows at key sites

By March 2023 more than half of modelled sites have a greater than expected chance of cumulative flows being below normal or lower for the time of year. The exception to this is sites in the north west and north east which have a greater than expected chance of being normal or higher. By September 2023 the majority of sites have a greater than expected chance of cumulative flows being below normal or lower for the time of year, except in the north east where cumulative flows are more likely to be normal for the time of year.

8. Projections for groundwater levels in key aquifers

By the end of March 2023 two-thirds of modelled sites have a greater than expected chance of groundwater levels being below normal or lower for the time of year, with the exception of the sandstone aquifer sites in the north west which are more likely to be above normal or higher. By the end of September 2023 most sites have a greater than expected chance of being normal or lower for the time of year. Sites, predominately in the chalk in the south east, east and north east have a greater chance of being below normal or lower.

9. About this report

Author: National Water Resources Hydrology Team, nationalhydrology@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 herein.

See the full report for October 2022 for more detail.