A further wet month building on the foundations laid since April this year, saw the phenomenon of summer groundwater recharge continue across the South East of England, allowing many rivers and aquifers to recover to conditions more usual for late winter than mid summer.

Rainfall

July was another wet month with double the long term average rainfall. The highest daily rainfall total of 44mm was recorded on the 7 th at Felbridge STW in the Eden catchment. Most of the rain fell in the first half of the month with warm dry weather prevailing in the last week of July. It was the 10 th wettest July on record – the second wettest in the last 50 years, with only July 2007 recording more rainfall. The past four months have seen exceptional rainfall for the time of year, the most on record (back to 1910) for April to July. Despite below average rainfall in May, the South East of England has still had an exceptional 190% of average rainfall since April. The persistent wet conditions of the past months contrast very markedly with the drought conditions in the South East over the winter of 2011-12.

Soil Moisture Deficit

Recharge and Groundwater Levels Soil moisture deficits are lower than normal for the time of year, and there have been some exceptional recharge totals which have been more in line with the averages we would expect during the winter months. Groundwater levels have continued to rise at most of the key sites this month, something only rarely observed at this time of year. At Chilgrove House, the site with the longest record in the Region, the last time significant summer rises in groundwater levels were seen was back in 1924. By the end of this month levels were the highest for the end of July for more than 100 years. Groundwater levels have recovered remarkably in the past three months from record lows at the end of March to some of the highest ever seen at this time of year in some areas. Jackaments in the Cotswolds Great Oolite had the second lowest levels on record for the time of year at the end of March, but this month had the second highest recorded in July. Recovery has been slower in some areas like the Chalk of the East Chilterns and Upper Lee as well as in parts of Kent, but in many places levels are now similar to average for the end of the winter period and are exceptionally high for the end of July.

River Flows

River flows responded to the rainfall during the month and were the highest on record for July for the Lymington River, Itchen, Western Rother, Arun, Ouse and Medway. The Coln, Thames at Eynsham, Loddon, Wey, Thames at Kingston and Darent all had the second highest July flows on record. A total of fifty five flood alerts were issued across the region, mainly for urban catchments, and in Essex, two flood warnings were issued on the Rivers Roding and Ingrebourne after heavy rain on the 7 th . Reservoir Storage/Water Resource Zone Stocks Reservoir storage is above average across the region as reservoirs have benefited from the elevated rainfall and river flows in the past four months. Reservoir stocks have remained stable throughout the month with the exception of Bough Beech.

Full report