Research and analysis

Yorkshire water situation: September 2024 summary

Updated 11 October 2024

Applies to England

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

1. Summary

This month, the rainfall in Yorkshire was above average overall but concentrated in the final week. The soils began the month dry but were mostly wet by the month’s end. Daily mean river flows were mostly normal but became high in the last 5 days. Groundwater levels were normal or above at most monitoring locations and reservoir stocks remained a little below the long term average (LTA).

2. Rainfall

September’s rainfall was above average within all catchments according to the MET Office Had-UK Grid data set. The monthly rainfall totals ranged between 132% of the LTA in the Wharfe catchment and 228% in the Esk catchment. The Esk and Hull catchments were categorised as exceptionally high, whilst all other catchments were either notably high or above normal.

Monthly rainfall recorded at our key indicator sites ranged from 65.6mm at Winestead in the Hull catchment to 179.1mm at Randy Mere in the Esk catchment.

The first and third weeks of September featured settled conditions. Moderate rain fell in the Pennine catchments from days 7 to 9. For most catchments, the majority of the rain within the month fell at the end, with day 25, 26 and 30 recording the highest totals. The heaviest storm rainfall occurred over the Don, Rother and Esk catchments. For example, at Woodhouse Mill in the Rother catchment 91% of the LTA for the month fell in one day on day 30. Randy Mere rain gauge recorded its second highest daily total in its 22-year history on day 26.

3-month cumulative rainfall totals were normal across Yorkshire, except in the Esk and Rother catchments which had totals above normal. Looking further back, the cumulative 12-month rainfall totals were exceptionally high within all catchments.

3. Soil moisture deficit

Within most areas in Yorkshire, soils were dry for the majority of the month particularly in the Hull and Humber and lower Ouse regions. The western Pennines however, which began the month with normal soil moisture, became wet in the first week and remained this way throughout, ending the month saturated. The rainfall within the last few days of the month reduced soil moisture deficit across the rest of Yorkshire by 50mm to 60mm. By the end of September:

• the North Yorks Moors and upper Don were saturated and classified as wet

• central areas were classified as normal

• only the lower parts of the Don, Aire, Ouse and Hull catchments bordering the Humber remained dry 

4. River flows

Dry soils limited the response of rivers to rainfall during the first 3 weeks of September. Monthly mean flows in most catchments ranged from 70% to 136% of the LTA, classified as normal or above normal. The Rother at Whittington and the Esk at Briggswath had notably high monthly mean flows with 230% and 247% of their LTAs respectively, due to the heavy storm rainfall in those catchments in the final week.

In most catchments, daily average flows were normal, briefly increasing to above normal in the Pennine catchments around days 9 and 10 and briefly dropping to below normal around days 20 and 21. Throughout Yorkshire, including the Rye and Derwent, flows rose sharply on day 26 in response to heavy rainfall and all catchments had flows above normal and often higher. These continued in most catchments on day 27. After a brief recession, further heavy rain on day 30 produced above normal to exceptionally high daily mean flows.

The Rother showed lots of variation in its daily flows with periods of low flow in the first and third weeks. By day 22, flows became notably high and remained high. On day 30, the gauging station at Whittington recorded its sixth highest annual maximum (AMAX) flow in a 47-year record. This peak was considerably lower than in Storm Babet in October 2023 which resulted in the highest peak at this site.

The Esk at Briggswath recorded its fifth highest AMAX river level in its 32-year record on day 27.

In the chalk-fed Hull catchment flows declined slightly in the second and third weeks. There was a brief and only moderate increase in flow in response to rainfall on day 26 to 27. A similar response was observed to rain on the last day of the month.

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 notably low 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 increased at the 2 key well sites. Great Ouseburn remained exceptionally high for the time of year, with Riccall Approach Farm remaining in the normal range.

5.4 Corallian Limestone

The groundwater level increased slightly within the Corallian Limestone at Sproxton and was just above normal at the end of the month.

5.5 Chalk

The groundwater level continued to decrease at both Wetwang (northern Yorkshire Wolds chalk) and Dalton Estate (central Yorkshire Wolds chalk). Levels were in the normal range for the time of year at both key wells.

6. Reservoir stocks

Total reservoir stocks were between 3% and 4% lower than the LTA this month. Reservoir stocks declined during the first 3 weeks but were replenished by heavy rain in the final week giving no significant overall change in the month. 

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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