Research and analysis

East Anglia water situation: March 2026 summary

Updated 14 April 2026

Applies to England

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

1. Summary

March rainfall across East Anglia ranged from 51% to 74% of the long term average (LTA) for the month. With below average rainfall in March, the soil moisture deficit (SMD) for East Anglia increased by approximately 17mm between the end of February and the end of March. However, the SMD for East Anglia remains normal for the time of year. The majority of river flow report sites recorded normal flows for the time of year. Groundwater levels have continued to increase at the majority of reporting sites, with 6 sites showing a decline in groundwater levels since February. All report sites for which there is data available, except Bircham Newton, ended March 2026 with groundwater levels categorised as above normal or normal for the time of year. Public water supply reservoirs ended March with levels ranging from 82% to 98% of their full storage capacity.

2. Rainfall

Below average rainfall was received across all East Anglia catchments in March 2026. Rainfall totals across East Anglia ranged from 51% to 74% of the long term average (LTA) for the month. The East Anglia area average rainfall for March was 24mm. This total is approximately 60% of the 1991 to 2020 LTA for March and is considered below normal for the time of year. Northern catchments were typically slightly wetter than catchments to the south, with North Norfolk receiving the highest rainfall total of 33mm and South Essex receiving the lowest rainfall total of 17mm for the month. East Anglia rainfall totals across all catchments over the past 3 months have been above normal or notably high. Over the past 12 months, cumulative rainfall totals ranged between 85% and 104% of the LTA, with most catchment totals being categorised as normal for the time of year.

3. Soil moisture deficit and recharge

Following below average rainfall in March the SMD for East Anglia has increased from 3mm at the end of February to 20mm by the end of March 2026. However, the SMD remains normal for the time of year. There is little variation in SMD values across the area, with all catchments having SMD values in the range of 11mm to 40mm. The hydrological catchments with the highest SMDs are located in the south of the area, with South Essex recording the highest SMD of 27mm at the end of March.

4. River flows

March 2026 month mean river flows ranged between 49% to 123% of the LTA, with the majority of river flow report sites categorised as normal for the time of year. In the east, the Waveney and Gipping catchments recorded below normal flows for the time of year, with the Ouzel catchment in the south west of the area, also recording below normal flows. The Gipping catchment recorded the lowest flows, with the month mean river flow being 49% of the LTA for the time of year. The highest flows were typically towards the centre and west of the area, with the Wissey catchment recording 123% of the LTA.

5. Groundwater levels   

Groundwater levels have continued to rise in the majority of reporting sites, for which there is data available, for March 2026. Six reporting sites have shown receding groundwater levels through March, indicating a truncated recharge season. All report sites, except Bircham Newton, ended March with groundwater levels categorised as above normal or normal for the time of year. Bircham Newton in north west Norfolk, ended March with groundwater levels categorised as below normal for the time of year.

6. Reservoir stocks

Public water supply reservoir levels ranged from 82% to 98% of their full storage capacity. Alton and Abberton reservoirs ended the month with levels above their respective normal operating curves. Grafham, Ardleigh and Hanningfield reservoirs ended the month with levels below their respective normal operating curves.

7. Forward look

7.1 Probabilistic ensemble projections for river flows at key sites

The river flow projections indicate an approximate 40% or higher probability of normal flows by June 2026 at all forecast sites. For September 2026, flow projections indicate a high probability of normal flows or above for all sites except for the Ely Ouse Denver, which has a higher probability of normal or below normal flows by September 2026.

7.2 Probabilistic ensemble projections for groundwater levels in key aquifers

The groundwater projections for September 2026 show a high probability of normal to below normal groundwater levels at most forecast sites. Smeetham Hall projections show an approximate 60% probability of notably high groundwater levels by September 2026. The projections for March 2027 show a high probability of normal or higher levels at the majority of forecast sites. Bircham Newton and Newmarket show a higher probability of below normal or lower groundwater levels by September 2026.

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.