Research and analysis

North-west England water situation: May 2025 summary

Updated 12 June 2025

Applies to England

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

1. Rainfall

Rainfall for north-west England during May was classed as normal with 93% of the long term average (LTA). The Cumbria and Lancashire (CLA) area observed 103% of the LTA classed as normal while the Greater Manchester, Merseyside and Cheshire (GMC) area observed 80% also classed as normal.

Despite the weather being dry for the first 2 weeks of May, higher rainfall during the remainder of the month has resulted in hydrological areas across north-west England observing rainfall classed between normal and above normal. One hydrological area observed rainfall classed as above normal while all others observed normal rainfall. The highest rainfall (in terms of LTA) was observed in the Kent hydrological area with 120% of the LTA classed as above normal and the lowest was observed in the Douglas with 77% of the LTA.

Cumulative rainfall over the past 3 months was classed between exceptionally low and notably low with higher rainfall (in terms of LTA) being recorded in southern GMC and western Cumbria. The 3-month cumulative rainfall was lowest in the Mersey and Irwell hydrological area with 47% of the LTA classed as exceptionally low and highest in the Esk (Cumbria) hydrological area with 62% of the LTA classed as notably low. For north-west England this was the fourth lowest rainfall recorded for the 3-month period ending in May since 1871. The Eden, Esk (Dumfries) and Mersey and Irwell hydrological areas all recorded their second lowest 3-month cumulative rainfall ending in May since 1871.

The 6-month cumulative rainfall for north-west England was classed between normal and exceptionally low with higher rainfall being observed in GMC and lower rainfall observed further north with the lowest being observed in the north of Cumbria. The highest 6-month cumulative rainfall was observed in the Cheshire Rivers Group hydrological area with 94% of the LTA classed as normal and the lowest was observed in the Esk (Dumfries) with 52% of the LTA classed as exceptionally low. This was the fifth lowest 6-month cumulative rainfall period ending in May recorded for north-west England since 1871 with the Esk (Dumfries) hydrological area recording the second lowest rainfall for this same period.

The 12-month cumulative rainfall for north-west England was classed between exceptionally low and above normal. The spatial variability of rainfall across the north-west remains largely the same as that seen for the 6-month totals with the highest rainfall recorded in GMC and the lowest in the north of Cumbria. The highest rainfall was observed in the Cheshire Rivers Group with 108% of the LTA classed as above normal and the lowest was observed in the Esk (Dumfries) with 69% of the LTA classed as exceptionally low.

2. Soil moisture deficit and recharge

Soil moisture deficits (SMD) across north-west England at the end of May were between 40mm and 100mm. Despite higher rainfall during the second half of the month, SMDs for north-west England were higher than expected for the time of year for all areas by between 26mm and 50mm.

3. River flows

Monthly mean river flows across north-west England were classed between normal and exceptionally low with:

• 12 monitoring stations classed as normal
• 4 monitoring stations classed as below normal
• 5 monitoring stations classed as notably low
• 4 monitoring stations classed as exceptionally low

The highest monthly mean river flow (in terms of LTA) was recorded in the River Esk at Cropple How with 95% of the LTA classed as normal and the lowest was recorded in the River Derwent at Seaton Mill with 33% of the LTA classed as notably low.

4. Groundwater levels   

Groundwater levels across north-west England at the end of May were classed between exceptionally low and exceptionally high. Groundwater levels at:

• Bruntwood Hall, increased, to exceptionally high from notably high
• Furness Abbey, decreased, to above normal from notably high
• Richmond Park, decreased, to notably high from exceptionally high

All other sites remained the same classification at:

• Brown Bank Lay-By, classed as normal
• Great Musgrave, classed as exceptionally low
• Lea Lane, classed as normal
• Primrose Hill, classed as normal
• Priors Heyes, classed as exceptionally high
• Skirwith, classed as normal
• Victoria road, classed as below normal

Please note, levels at Priors Heyes remain high compared to historic levels because the aquifer is recovering from the effects of historically high abstractions.

5. Reservoir stocks

Total reservoir stocks for north-west England decreased from 71% at the end of April to 61% at the beginning of June. This is lower than the average of 84% usually seen at this time of year and also lower than last year when total reservoir stocks were 91%.

At the beginning of June, reservoir storage (in terms of percentage) was highest at Vyrnwy at 87% full and lowest at Rivington at 27%.

The combined storage at Haweswater and Thirlmere was 49% which is lower than the 77% average storage at this time of year and lower than last year when storage was 94%.

Reservoirs kept low for maintenance works include part of the:

• Longdendale system – Audenshaw No.1, Torside
• Rivington system – Anglezarke, and High Bullough
• Bolton supply system – Dingle
• Piethorne Valley system – Norman Hill, Kitcliffe, and Rooden
• Ogden (Barley) system – Ogden Lower, and Ogden Upper
• Barnacre Group system – Barnacre North
• Longridge system - Alston No.1, Alston No.2, and Spade Mill No.2
• Dee (Celyn and Brenig) system – Llyn Celyn
• Dubbs system – Dubbs
• Watergrove system – Watergrove

6. Water abstraction restrictions

At the end of May, one abstraction license was being constrained in the GMC area to protect water resources and the environment. No water abstraction licenses were constrained in the CLA area.

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.

Author: Cumbria and Lancashire Hydrology Team, hydrology.CMBLNC@environment-agency.gov.uk