Research and analysis

Yorkshire water situation: August 2024 summary

Updated 13 September 2024

Applies to England

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

1. Summary

This month, Yorkshire experienced well below average rainfall. The soils dried, but daily mean river flows remained in the normal range in most catchments. Groundwater levels decreased across all aquifers. Reservoir stocks also declined, falling below the long term average (LTA).

2. Rainfall

Overall, the amount of rainfall within all catchments in Yorkshire this month was low when compared with the LTA using the MET Office Had-UK Grid data set. The monthly rainfall totals ranged between 24% of the LTA in the Ouse and 66% of the LTA in the Ure catchment. In the Ouse, Rye, Derwent and Esk catchments it was the sixth to eighth driest August in the 154-year Had-UK data set, while in the Hull catchment it was the ninth driest. The Esk, Rye, Derwent and Ouse catchments were classified as exceptionally low monthly rainfall. All other catchments in Yorkshire were categorised as below normal or notably low.

Rainfall recorded at our key indicator sites over the month ranged from 179.4mm at Tow Hill in the upper Ure to just 8.4mm at Crakehall Hunters Hill in the middle Swale catchment. In the Pennines, the heaviest rainfall occurred on 8, 21 to 22, and 27 August. Further east the 8 and 22 August were the wettest days, with many dry periods in the month.

3-month cumulative rainfall was below normal or notably low everywhere apart from the Esk, which was normal. Due to preceding wet seasons, cumulative 12-month rainfall totals remained notably high or exceptionally high for all catchments in the Yorkshire area.

3. Soil moisture deficit

Soils dried rapidly during the first 3 weeks of August. At month-end soils were classified as very dry in the lower Ouse, Hull and Humber regions. Aside from the western Pennines, which remained normal, the rest of the Yorkshire area had dry soils. The last week of this month was the sixth consecutive week of the lower Ouse and Humber areas being classified as dry or very dry.

4. River flows

Monthly mean river flows ranged from normal to below normal for the majority of catchments, between 36% and 89% of the LTA, increasing to 116% of the LTA on the West Beck in the Hull catchment. The Rother was exceptionally low at 32% of the LTA.

Over the course of the month, the Esk, Rye, Derwent and Hull catchments all showed an overall decline in flow. They began with above normal daily mean flows which soon reduced to flows in the normal range. Despite the low August rainfall, flows in the Rye, Derwent and Hull catchments were supported by groundwater sources and in the Esk due to the wet antecedent conditions in July.

The Rother catchment had notably low flows for most of the month. These also lessened and were classified as exceptionally low for the last 6 days of the month. The Calder was mostly below normal throughout, while the Aire and Don had flows in the normal range. Flows in the Swale, Ure, Ouse and Wharfe catchments were normal for the majority of the month. They increased to above normal and notably high around 9 August and 23 to 27 August, responding to the periods of rain in these catchments.

5. Groundwater levels 

5.1 Magnesian Limestone

The groundwater level within the Magnesian Limestone at Brick House Farm continued to decrease but remained exceptionally high for the time of year.

5.2 Millstone Grit

The groundwater level continued to decrease within the Millstone Grit at Hill Top Farm and dropped to below normal for the time year. It should be noted that this observation borehole is used for water abstraction by means of a pump. Therefore, the groundwater level recorded here may be subject to the effects of this.

5.3 Sherwood Sandstone

The groundwater level in the Sherwood Sandstone continued to decrease, with Great Ouseburn remaining exceptionally high but Riccall Approach Farm decreasing to normal.

5.4 Corallian Limestone

The groundwater level decreased within the Corallian Limestone at Sproxton and became normal for the time of year.

5.5 Chalk

The groundwater level decreased at both Wetwang (northern Yorkshire Wolds chalk) and Dalton Estate (central Yorkshire Wolds chalk). Groundwater levels at Wetwang decreased to normal while Dalton Estate remained above normal.

6. Reservoir stocks

Yorkshire Reservoir Stocks started August around 2% above the LTA. Stocks decreased by around 10% throughout the month and in the third week fell below the LTA for the first time since July 2023. Reservoir stocks were 2.8% below the LTA at the end of August.

7. Environmental Impact

At the end of August 32 abstractions were affected by Hands off Flow restrictions. Sixty-eight abstractors had been given notice that flows were low but were still able to abstract. The restrictions were distributed widely across Yorkshire’s catchments.

Author: Environment Agency, hydrology.northeast@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.  

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