East Anglia water situation: October 2024 summary
Updated 13 November 2024
Applies to England
© Crown copyright 2024
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1. Summary
On average, October was slightly wet for the time of year, most catchments receiving only a little more than 100% of their long term average (LTA) rainfalls for the month, and only one catchment falling below average. A significant portion of this rainfall occurred at the very beginning of the month, following on from the very wet conditions during the final weeks of September. Soil moisture deficits (SMD) which had been decreasing since middle of September and the onset of this rainfall began to increase again through October, recovering from exceptionally low to normal levels within the month. River flows were particularly high within the western catchments, with the Great Ouse and all its tributaries being exceptionally high for the month. This flow was large at the start of the month but has since decreased significantly as rivers have recovered from September’s rainfall. All public water supply reservoirs have levels above their respective normal operating curves.
2. Rainfall
October 2024 started as a very wet month, following on from the significant rainfall received at the end of September. October 1st alone received over 20% of the region’s average total rainfall for the month, after which daily rainfall totals reduced significantly. Within the last 12 months East Anglia has received 800mm of rainfall, 174mm greater than the long term average. This is the fourth highest November to October 12-month total on record going back to 1871.
3. Soil moisture deficit and recharge
After significantly dropping to extremely low levels towards the end of September with the cooler and wetter conditions, October 2024 saw SMD recover to normal levels with the drier conditions later in the month.
4. River flows
River levels were exceptionally high across many rivers towards the end of September with the large volumes of rainfall, persisting into the early days of October before gradually recovering to more baseflow driven conditions. The Rhee, Great Ouse, and all of its tributaries averaged exceptionally high levels due to the volumes of flow at the beginning of the month. They have since recovered to normal or above normal levels.
5. Groundwater levels
After receding for several months, groundwater levels at multiple report sites have begun to rise again, with the reduction at many more plateauing. These changes have occurred mostly within the Ouse catchments which saw the greatest rainfall totals. Hindolveston and Costessey in the northeast are the only sites remaining at normal levels while all others are notably high or higher.
6. Reservoir stocks
At the end of October 2024, all water company reservoirs in East Anglia were above their respective normal operating curves. While most are significantly above their operation curves, Grafham reservoir is only marginally above its own.
7. Forward look
7.1 Probabilistic ensemble projections for river flows at key sites
For all surface water sites there is a high probability of flows being above normal or higher for December 2024, with a higher probability for normal flows across all catchments excluding the Ievel for March 2025.
7.2 Probabilistic ensemble projections for groundwater levels in key aquifers
Groundwater levels at all sites have a high probability of above normal or higher levels in March 2025 and September 2025 and a very high probability of normal or higher levels. The probability of below normal or lower flows at Bircham Newton and Therfield Rectory is less than 1% for March and September 2025.
Author: ANG-Hydrology@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.