According to the Environment Agency’s monthly water situation report for August , it was the wettest August for 10 years across England with 157% of the long term average rainfall recorded.
Rainfall totals were classed as notably high for the time of year in the east and southeast, and above normal elsewhere. With the wetter conditions, soil moisture deficits generally decreased through August. Monthly mean river flows for August were normal for the time of year at half of the Agency’s indicator sites and above normal or higher at the other half.
Groundwater levels decreased at all but two of the indicator sites, but remain normal or higher for the time of year at all sites. Reservoir stocks mostly decreased across the country during August, with overall storage in England at 81% of total capacity at the end of the month.
Rainfall
During August, the highest rainfall totals (more than 160 mm) fell across parts of Cornwall and Cumbria, whilst the lowest rainfall totals (less than 80 mm) fell across parts of Northumberland, Lincolnshire and Oxfordshire (Figure 1.1). August rainfall totals were above the August long term average (LTA) in all hydrological areas across England. The highest August rainfall totals as a percentage of LTA were in East Sussex where more than 220% of the LTA fell.
August rainfall totals were classed as above normal or notably high at more than four fifths of the hydrological areas across England. Cumulative rainfall totals for the 3 months ending in August were normal across most of England, with above normal totals in parts of eastern England. The exceptional winter rainfall is still influencing the cumulative 12 month rainfall totals, with much of England classed as above normal to exceptionally high (Figure 1.2).
Rainfall totals for August were above normal or notably high in all regions of England. Regional monthly totals as a percentage of the August LTA ranged from 137% in the northwest to 176% in southeast England. Overall, England received 157% of the August LTA rainfall, the wettest August since 2004 (Figure 1.3). It has been the wettest 12 month period on record (starting in 1910) ending in August in southwest England, and the second wettest in southeast England.
Reservoir storage
Reservoir stocks decreased at the majority of our reported reservoirs and reservoir groups during August. The largest decrease of in storage was 15% of total capacity reported for Hanningfield reservoir in east England. Grafham and Farmoor reservoirs by decreased by 6% and 9%, respectively. These three reservoirs are classed as being below normal for the time of year. Decreases of at least 10% were reported for 5 other reservoirs in southwest England, but reservoir stocks for the end of August for these, and the remaining reservoirs and reservoir groups, remain normal or higher for the time of year (Figure 5.1).
The broad-scale picture for August was that the reservoir stocks decreased across almost all English regions during the month. The exception was in the northwest, where reservoir storage increased very slightly (by less than 1%). Elsewhere, the decrease in reservoir storage ranged from 9% in southwest England to 1% in central England. At 64% of total capacity, the reservoir stocks for the end of August in northwest England remain lowest across England, with the stocks in southeast England remaining highest at 89% of total capacity. Overall reservoir storage for England decreased by 2% during August to 81% of total capacity