East Anglia water situation: September 2025 summary
Updated 14 October 2025
Applies to England
© Crown copyright 2025
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1. Summary
Rainfall for September 2025 was standard for the time of year, with rainfall totals within the normal range across all areas. The overall soil moisture deficit (SMD) changed little over the course of the month, the regional average increasing from 124mm at the end of August to 125mm by the end of September. Some of the more reactive rivers showed a temporary response to observed rainfall, though have since fallen with little change to base flow. Groundwater levels continue to fall, with all sites at normal or lower levels. Public water supply reservoir stocks ended the month ranging from 52% to 69% capacity.
2. Rainfall
Rainfall during September 2025 ranged from 81% to 122% of the long term average (LTA) for the month. East Suffolk received noticeably more than other catchments, receiving the higher 122% with the only other catchment receiving more than 100% of the LTA being the Upper Bedford Ouse at 107%. The cumulative 3-month total rainfall for all catchments has been below normal, with the exception of East Suffolk and Broadland Rivers which have instead received normal totals. The cumulative 6-month total shows the extent of the dry spring and summer seen this year, with exceptionally low totals across south-western catchments, and notably low totals across the northeast, again with the exception of East Suffolk which is below normal.
3. Soil moisture deficit and recharge
The regional SMD at the end of September was 26mm to 50mm higher than normal for the time of for all catchments with the exception of East Suffolk, North Essex and South Essex which were 6mm to 25mm above the LTA. Fenland was the only catchment to end the month with an SMD greater than 131mm.
4. River flows
River flows across East Anglia during September 2025 continued to recede, displaying only a temporary response to the observed rainfall throughout the month. Monthly average flows ranged from 28% to 107% of the LTA, the Ivel being the only river with above normal flows and both the Ely Ouse and Wissey displaying exceptionally low flows. Flow at Denver on the Ely Ouse have dramatically increased compared to August, the monthly average increasing from 3% to 35% of the LTA in September.
5. Groundwater levels
Groundwater levels continue to fall across all catchments which is expected for the time of year. Levels range from above normal at Therfield to exceptionally low in Costessey. While levels have dropped at all sites, some have fallen at a reduced rate, both Washpit Farm and Breckland ending the month at a higher banding than they did for August despite lower levels.
6. Reservoir stocks
All reservoirs with the exception of Abberton have fallen below their respective normal operating curves for the time of year as stocks continue to fall. Stocks ended the month ranging from 52% to 69% capacity.
7. Forward look
7.1 Probabilistic ensemble projections for river flows at key sites
Surface water flows are projected to continue declining, with a higher likelihood of below normal or dryer flows at all sites with the exception of the Ivel by December 2025. The March 2026 projection forecasts slightly higher odds of drier flows, with increased likelihood of notably low and exceptionally low flows.
7.2 Probabilistic ensemble projections for groundwater levels in key aquifers
Groundwater levels are projected to continue dropping, and have a high chance of being either below normal or lower levels by March 2026. The September 2026 projection predicts much the same, though with a higher likelihood of lower levels. Redfield is an exception to both projections, with a high degree in confidence of normal or higher levels.
Author: Hydrology Team, hydrology-ean-and-lna@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.