Research and analysis

Water situation: January 2024 summary

Updated 12 December 2024

Applies to England

England experienced 85mm of rainfall during January which is a noticeable reduction when compared to the preceding months although still above average. Five catchments: Wear, Don, Calder, Derwent, and Mersey and Irwell, reported the wettest 6 month August to January period since records began in 1871. Soil moisture deficits (SMD) across the county remained close to zero for a third consecutive month. River flows decreased at almost two-thirds of reporting sites, however flows at all sites were classed as normal or higher for the time of year. Groundwater levels increased throughout England with almost all sites classed as normal or higher by the end of the month. Almost half of reporting reservoirs experienced a decrease in storage in January, most reservoirs are classed as normal or higher for the time of year.

1. Rainfall

The January rainfall total for England was 85mm which represents 106% of the 1961 to 1990 long term average (LTA) for the time of year (102% of the 1991 to 2020 LTA). All catchments throughout the country received above average rainfall during January. The wettest hydrological areas relative to the LTA were the Kent, and Wyre and Lune catchments in the south-east and north-west of England, which received 164% and 163% of LTA rainfall respectively. The driest hydrological areas were reported in the south-west of the country with North Cornwall, West Cornwall, and Otter Sid Axe and Lim catchments all reporting 73% of LTA rainfall during January.

January rainfall totals were classed as normal or higher for the time of year in all of the hydrological areas in England, with the majority of areas (85%) reporting normal rainfall totals for the month. The remaining twenty one areas (15%) located across the north and east of England, reported either above normal, or notably high rainfall during the same period. Rainfall totals at a regional scale during January, were classed as above normal in north-east and north-west England, with the remaining 4 geographical regions classed as normal.

The 3-month cumulative rainfall totals for almost all areas throughout England were classed as above normal or higher. The north of the county received the greatest rainfall totals during this period with many areas classed as exceptionally high. The majority of catchments (52%) across the north and east of England, reported exceptionally high 6-month cumulative rainfall totals. Five catchments: Wear, Don, Calder, Derwent (Midlands) and Mersey and Irwell, reported the wettest 6-month period since records began. The 12-month cumulative rainfall totals show only 4 hydrological areas (3%) were classed as normal, 12 (9%) as above normal, 47 (34%) as notably high, and a majority of 76 (55%) classed as exceptionally high. The Kent Catchment experienced its wettest 12-month period since records began. Notably, the Esk (Dumfries) area in the north-west of England was the only catchment to report normal rainfall throughout all accumulation periods.

2. Soil moisture deficit

SMD throughout England remained close to zero during January, continuing trends first observed towards the end of October 2023. However small increases in SMD (soils becoming drier) were observed, with several areas reporting marginal increases of around 1mm.

Across all of England soils were close to field capacity, with all reported SMDs observed to be smaller than the LTA, leaving soils wetter than average at the end of January.

January monthly mean river flows decreased at almost two-thirds of indicator sites when compared to the previous month. River flows at all sites were classed as normal or higher for the time of year.  However, many of the rivers we report on (67%) continue to experience flows classed as either above normal or notably high for the time of year. The River Kennet at Marlborough, and River Burn at Burnham, reported the highest monthly mean flows on record for the January period (records for Marlborough and Burnham date from 1972 and 1970 respectively).

January saw monthly mean river flows decrease at the majority (66%) of regional index sites when compared to December. However, flow increases were reported at Offord in the east of England on the River Ouse, and Kingston on the River Thames, with the resulting flows now classed as notably high and exceptionally high respectively. Despite a decrease in monthly mean flows, Carlton (River Lune) continues to be classed as notably high, alongside Marston-on-Dove (River Dove), and Haydon Bridge (South Tyne) both classed as above normal for the time of year. Horton (Great Stour) and Thorverton (River Exe) also reported a reduction in mean flow and are now classed as normal for the time of year.

3. Groundwater levels   

By the end of January, groundwater levels rose at over half of the indicator sites we report on. Groundwater levels at the majority of groundwater sites (96%) were classed as normal or higher by the end of the month. A quarter of indicator sites, located across north-east and south-east England, were classed as exceptionally high, with Coxmoor (Idle Torne Nottinghamshire & Doncaster Permo Triassic Sandstone) in central England reporting the highest groundwater levels for January since records began in 1990. Lea Lane in north-west England was the only site to report below normal levels by the end of the month.

Groundwater levels at major aquifer index sites varied across January, with an equal 50% of aquifers reporting an increase and decrease in level. Dalton Estate (Hull and East Riding Chalk) was classed as exceptionally high. While Both Skirwith (Carlisle Basin Sandstone) and Stonor Park (Chalk) were classed as notably high. Chilgrove (Chichester Chalk) and Little Bucket (Stour chalk) were classed as above normal. Jackaments Bottom (Burford Jurassic Limestone) was the only location during January to be classed as normal.

4. Reservoir storage

Reservoir storage throughout England varied across January, with almost half of reporting reservoirs experiencing a decrease in storage, with only a third reported an increase. By the end of the month storage at the majority of reservoirs (81%) was classed as normal or higher for the time of year. All Reservoir storage volumes at the end of January varied by less than 10% when compared to volumes observed at the end of December 2023. Refill at several reservoirs may have been impacted by either planned works or reactive maintenance. Consequently, volumes reported by Bewl, Dee, Grafham, and the Lower Lee Group are being actively managed, and may not reflect typical storage for the time of year.

At a regional scale, total reservoir storage increased by an average of 3% across the north-west, south-west, and south-east of England, and decreased by an average 2% in north-east, east, and central England by the end of January.

5. Forward look

February began with milder and wet conditions across England. The wetter conditions will be followed by a more settled and drier period across the rest of the month although there will still be a chance of showers, which may fall as snow with the ongoing cold conditions.

For the 3 month period for the UK from February to April, there is a slightly higher than normal chance of cold conditions bringing with it an increased chance of impacts from ice, fog and snow during February and March. During this period precipitation is likely to be around average for the time of year.

6.  Projections for river flows at key sites

By the end of March 2024, river flows in south-east, south-west, east and central England have a higher than expected chance of being above normal or higher. This is particularly true for those in groundwater fed catchments where groundwater levels are currently higher than expected for the time of year and can support river flows over the next 2 months.

By the end of September 2024, river flows across most of England have the greatest chance of being above normal or higher, except in the north-west where flows are more likely to be normal.

7. Projections for groundwater levels in key aquifers

By the end of March 2024, groundwater levels in east, south-east, north-west and north-east England have a greater likelihood than expected of being above normal or higher. Sites in chalk aquifers are likely to be above normal or higher. South-west and central England groundwater levels have a greater likelihood of being normal or higher.

By the end of September 2024, groundwater levels have a greater likelihood of being above normal or higher in north-west, north-east, south-east and east England. In south-west and central England, groundwater levels have a greater likelihood of being normal or higher.

Author: Environment Agency, 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 in this report.