Research and analysis

East Anglia water situation: June 2024 summary

Updated 12 July 2024

Applies to England

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

1. Summary

June 2024 was the driest month for East Anglia within the past year, standing out from the last 12 months of wet weather. All catchments received the lowest percentage of rainfall relative to their long term averages, most seeing below normal totals with some catchments receiving notably low totals. River flows all continue to receive normal to exceptionally high flows, though this can be attributed to base flow from the high groundwater levels caused by several months of healthy recharge. Soil moisture deficit (SMD) continues to increase and is now at a level normal for the time of year.

2. Rainfall

June 2024 was significantly drier than all other months within the past year, ranging between 28% and 70% of the long term average (LTA) for June. Little difference has been made to the 6 and 12 month totals, which are still dominated by exceptionally high totals owing to the wet months we have had recently. The 3 month total has shifted much closer to normal, with all areas being either normal or above normal with the exception of the Cam catchment which is above normal at 126%.

3. Soil moisture deficit and recharge

SMD significantly increased throughout June with the warmer temperatures and significant reduction in rainfall. Previous occasions it began to rise within recent months were stopped by sudden and significant periods of rainfall which slowed the increase in deficit and caused it to decline. However, with low rainfall totals this June there was no damper to the prevailing warm conditions and the deficit has risen significantly to levels normal for the month.

4. River flows

River flows ranged between 88% and 172% of the LTA for June. Though the total rainfall received significantly declined this month compared to the past 12, groundwater levels are still very high due to the months of continuous recharge. Consequently, base-flow contributions to rivers has been high, and flows remain above normal and notably high for several rivers. Catchments in the west of the region however have already returned to normal flows for the time of year.

5. Groundwater levels   

Groundwater levels remain high across East Anglia, with all catchments demonstrating above normal, notably or exceptionally high levels compared to the LTA. The warm, dry weather this month will have provided little recharge to groundwater stores, and a downward trend is noticeable at almost all groundwater sites. While levels are still very high for the time of year owing to the wet winter, levels are declining towards normal conditions.

5.1 Reservoir stocks

Reservoir stocks are healthy this month. Hanningfield is the least filled at 89.95% of capacity and is above it’s normal operating curve. Alton and Abberton are slightly above 90% of capacity and both Ardleigh and Grafham are at 95% capacity. Both Alton and Grafham are slightly below their normal operating curves.

6. Forward look

6.1 Probabilistic ensemble projections for river flows at key sites

Modelled simulations of all rivers suggest all forecasted rivers will have normal, above normal or greater flows by September 2024 with above 99% probability. Only the Ely Ouse is forecasted to have any significant probability of below normal flows with 25%. The Ivel has above 99% probability of being above normal or greater, with the Kym, Bedford Ouse and Ouse ranging from approximately 50% to 80% for above normal flows or greater.

For December 2024, there is a 30% probability for below normal or notably below normal flow for all rivers with the exception of the Ivel which is approximately 15%.

6.2 Probabilistic ensemble projections for groundwater levels in key aquifers

For September 2024, no groundwater models suggest significant probability of below normal levels, and only Newmarket and Bury st Edmunds predict significant probability of normal levels. Kenninghall and Redlands are expected to have exceptionally high levels with the model returning 100% probability.

For March 2025, all boreholes are forecasted to have some probability of below normal or notably low levels, ranging from approximately 10% to 40%, with the exception of Redlands with no significant probability.

Author:  Hydrology team, 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.