Research and analysis

East Anglia water situation: November 2024 summary

Updated 13 December 2024

Applies to England

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

1. Summary

Rainfall across East Anglia, through the month of November, was average for this time of year, following a similar trend in October 2024, with rainfall across the region’s catchments ranging from 71% to 139% of the long term average (LTA). A significant portion of that rainfall came towards the end of month, seen by spikes in the river hydrographs in response to the increased precipitation. Soil moisture deficits (SMD) reduced as a result of the rainfall towards the end of the month and average around 16mm across East Anglia. Groundwater levels remain healthy with most catchments sitting above normal, with the exception of the most northerly sites recording normal groundwater levels for this time of year. Public water supply reservoirs are either above their respective operating curve, or just below their operating curves.

2. Rainfall

November rainfall across East Anglia was predominately normal for the time of year, ranging from 71% to 139% of the LTA. Only the Upper Bedford Ouse saw an above normal rainfall total, 78.2mm or 139% of the LTA. The one month totals follow the trend over the past 3, 6 and 12 months where the western catchments have received above normal or greater levels of rainfall, while the eastern catchments have experienced normal or greater rainfall totals. The past 12 months rainfall totals remain exceptionally high for the western catchments, 127% to 158% of the long term average, while the rainfall for the region as a whole, from December to October, is the eighth wettest since 1871, at 777mm.

3. Soil moisture deficit and recharge

Cool and wet conditions throughout November allowed the SMD to reduce across East Anglia. In a similar trend to rainfall and groundwater levels, the west saw the smallest SMD figures, below 10mm surrounding the Ouse catchments, due to higher rainfall in the west in November 2024. The central and eastern catchments have an SMD within 11mm to 40mm, a normal level for this time of year. Region-wide SMD increased to 35mm by the middle of the month, but increased rainfall in the second half of November reduced the deficit to 16mm, on average across East Anglia.

4. River flows

There was an east to west split in river flow throughout November 2024. High rainfall in the west meant flows were above normal, ranging from 119% to 245% of the LTA. Central areas saw normal river flows ranging from 76% of the LTA on the Chelmer to 109% on the Cam. While the eastern catchments also saw normal river flow for the time of year, they were the lowest when compared to the long term average, ranging from 58% of the LTA on the Yare to 64% on the Colne.

5. Groundwater levels   

Groundwater levels have either begun to level out or rise after the summer recession in levels. Recovery has been strongest in the west of East Anglia, coinciding with the catchments experiencing the highest rainfall over the last month and the last 12 months. All groundwater sites recorded levels above normal, except Bury St Edmunds and Redlands Hall which recorded notably high levels for November, and Hindolveston, South Creake and The Spinney Costessey in the north of East Anglia that had normal groundwater levels for this time of year.

6. Reservoir stocks

By the end of November 2024, Ardleigh and Grafham were marginally below their respective normal operating curves, while Abberton, Alton and Hanningfield were comfortably above their operating curves.

7. Forward look

7.1 Probabilistic ensemble projections for river flows at key sites

For all surface water sites there is a high probability, over 70%, of flows being above normal by end of December 2024, with it being very unlikely any river flows will be below normal, all projections have the likelihood of below normal at 0% apart from Ely Ouse at 7%. By March 2025, it is likely flows will be normal or above normal, while flows are vulnerable to dropping to below normal, however this is projected to be a less than 25% likelihood at all sites apart from Kym which has 21% chance of flows being notably low.

7.2 Probabilistic ensemble projections for groundwater levels in key aquifers

Groundwater levels at key sites have a very high probability of being normal or higher by March and September 2025 and a high probability of being above normal or higher. The probability of below normal at all key sites is below 5% in March and September 2025, except Newmarket with 13% likelihood of levels below normal in March and Bury St Edmunds with 18% likelihood of levels below normal by September 2025.

Author: Hydrology Team, [email protected]

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.