Research and analysis

Water situation: March 2025 summary

Updated 11 April 2025

Applies to England

It was the driest March across England since 1961. It was an extremely dry month with all hydrological areas recording below average rainfall. Soil moisture deficits (SMD) increased across England, and soils becoming drier than would be expected for the time of year. Monthly mean river flows in March decreased at all the sites we report on and the majority of flows were classed as below normal or lower. Groundwater levels decreased at nearly three-quarters of sites however most sites remain classed as normal or higher for the time of year. Reservoirs stocks across England decreased during March, ending the month 89% full.

1. Rainfall

In March, England received 14.8mm of rainfall which represents 22% of the 1961 to 1990 LTA for the time of year (25% of the 1991 to 2020 LTA). All hydrological areas received below average rainfall during March.

The wettest hydrological area as a percentage of the LTA, was the Seaham Area in the north-east, having received 53% of LTA rainfall (26.6mm). In contrast the driest hydrological areas, relative to their LTA, were Teign and Torbay in south-west England, which received 4% of LTA rainfall (4.3mm).

Rainfall totals during March were classed as exceptionally low in 105 (76%) hydrological areas and notably low in 26 (19%) hydrological areas. Seven sites (5%), predominantly in Yorkshire were classed as below normal with only 1 site classed as normal for the time of year. Teign and Torbay in south-west England and the Upper Dee in Wales both recorded their driest March since records began in 1871. The 3-month cumulative totals were classed as normal across most of southern England, with northern England being classed as below normal or lower. Over the last 6-months, rainfall totals have been normal across much of the country with rainfall classed as below normal or notably low north-east and north-west England. The Esk Dumfries hydrological area in north-west England recorded the driest 6 months to March since records began in 1871. The 12-month cumulative totals were classed as normal or higher across all but 3 hydrological areas of England.

At a regional scale, rainfall was classed as exceptionally low in all regions except for the north-east which was classed as notably low for the time of year. England as a whole classed as exceptionally low and it was the sixth driest March for England since 1836.

2. Soil moisture deficit

Throughout March, due to the drier conditions SMD increased across all areas of England resulting in soils being drier than would be expected for the time of year.

At the end of March, SMD increases across England were greater than the long term average (LTA) for the time of year for most of the country meaning soils were drier than would typically be expected, although some soils across northern England remain closer to the LTA. Soils across south-west England were drier at the end of March that we have seen previously.

3. River flows

Monthly mean river flows decreased at all of the sites we report on in March. Flows at the majority (91%) of sites were classed as normal or lower for the time of year. Fourteen sites (25%) were classed as normal for the time of year. Fifteen sites (27%) were classed as below normal and 14 sites (25%) were classed as notably low for the time of year. Seven sites (13%), predominately in northern England, were classed as exceptionally low. Five sites across south-east and south-west England recorded flows above normal or higher.

During March, monthly mean river flows at all regional index sites decreased when compared to February. The naturalised monthly mean flow at Kingston (Thames) and the monthly mean flow for Offord (Bedford Ouse) were classed as normal. Flows at Horton (Great Stour) and Thorveton (Exe) were classed as below normal and notably low respectively. Three index sites at Marston-on-Dove (Dove), Caton (Lune) and Haydon Bridge (South Tyne) were classed as exceptionally low for the time of year, with Haydon Bridge in north-east England recording the lowest monthly mean flow for March since records began in 1974.

4. Groundwater levels   

At the end of March, groundwater levels decreased at nearly three-quarters of reporting sites (73%), with 7 sites (27%) seeing an increase compared to the previous month. All sites but 2 sites were classed as normal or higher for the time of year, with half of sites classed as above normal or higher. Eleven sites (42% of the total) were classed as normal for the time of year, and 8 sites (31%) were classed as above normal. One site (4%) was classed as notably high and 4 sites (15%) were classed as exceptionally high for the time of year, including Priors Heyes in the West Cheshire Permo-Triassic Sandstone (north-west England) and Weir Farm in the Bridgnorth Sandstone (central England) both recorded the highest end of March level since records began in 1972 and 1983 respectively.

Groundwater levels at major aquifer index sites reflected the mixed picture across England with groundwater levels classed as normal for the time of year at only 3 sites: Dalton Estate Well (Hull and East riding Chalk), Skirwith (Carlisle Basin Sandstone) and Little Bucket (East Kent Stour Chalk). Levels at Chilgrove (Chichester Chalk) and Redlands Hall (Cam Ely Ouse Chalk) classed as notably high for the time of year. Levels at Weir Farm (Bridgnorth Sandstone) and Stonor Park (South West Chilterns Chalk) remain classed as exceptionally high for the time of year. Levels at Jackaments Bottom (Burford Jurassic Limestone) decreased to be classed as notably low for the time of year.

5. Reservoir storage

During March, reservoir stocks decreased at nearly two-thirds of the reservoirs and reservoirs groups we report on. The largest decrease was reported at Haweswater and Thirlmere in north-west England which saw a decrease of 11%.

By the end of March, reservoir storage levels across the country ranged from notably high to exceptionally low for the time of year. Haweswater and Thirlmere, which supplies north-west England, was classed as exceptionally low for the time of year as it has been impacted by low inflows and planned maintenance in the resource zone over the winter. The Dee system, which also supplies north-west England, was classed as notably low for the time of year as it has been impacted by low inflows and drawdown for reservoir safety work. Eighteen reservoirs were classed as normal for the time of year. Five reservoirs were classed as below normal and four were classed notably low for the time of year. Reservoir stocks at Farmoor in south-east England increased after turbidity issues restricted refill in February. Levels at Abberton in east England also increased after reservoir safety works were complete. By the end of March total storage across England was reported as 89%, a decrease of 3% since the end of February.

6. Forward look

April started with a week of little to no rainfall across England. Conditions are expected to remain dry for many, before a cold front brings some rain, showers and fresher conditions towards the middle of the month. Some heavy and thundery rain in places as a wetter period sets in, bringing temperatures closer to normal for the time of year. Towards the end of April settled conditions are expected to return and continue into early May.

For the 3-month period from April to June there is a higher than normal chance of conditions being warmer than average. Rainfall is likely to be similar to normal, with a balanced chance of a wet or dry period. There is a residual risk of impacts from late season frosts, and later in the period, the chance of warm conditions is higher implying are greater than normal chance of heatwaves in the early summer.

7. Projections for river flows at key sites

By the end of September 2025, river flows across most of England have the greatest chance of being normal or lower for the time of year. The exceptions are east and north-west England where there is a slightly greater chance of river flows being above normal or higher.

By the end of March 2026, river flows have the greatest chance of being below normal or lower across almost all of England. In north-west and east England, river flows have the greatest chance of being normal for the time of year.

8. Projections for groundwater levels in key aquifers

By September 2025, groundwater levels have a greater chance of being above normal or higher in south-west and east England. All other regions have the greatest chance of being normal for the time of year.

By March 2026, groundwater levels in east and north-east England have the greatest chance of being above normal or higher for the time of year. All other regions, groundwater levels have the greatest chance of being below normal or lower. 

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 in this report.