The Environment Agency latest Water Situation report shows conditions in October contrast sharply to the same time last year when rainfall, river flows and groundwater levels were all very low.  

Summary – October 2012

Following the general trend starting in April this year, October was a wet month. River flows and groundwater levels responded to the rainfall as soils became saturated. Conditions this October contrast sharply to the same time last year when rainfall, river flows and groundwater levels were all very low.

Rainfall

October was a wet month with 166% of long term average rainfall in the South East. The wettest day was the 5th , and the highest daily rainfall total of 34 mm was recorded on the 17 th at Osney Lock on the River Thames in Oxford. It has been the wettest October for 8 years in the South East, and the past 7 months have been the second wettest April to October on record. The same period in the year 2000 was the wettest in the 102 year record. This month contrasts with last October, when the South East only had 45% of average rainfall. The switch from dry conditions to wet is very marked with 160% average rainfall for the South East in the last 7 months and only 63% of average in the 7 months prior to this. Soil Moisture Deficit, Recharge and Groundwater Levels By the end of the month,

Soil Moisture

Deficits were mostly zero across the region, as persistently wet weather saturated the ground. Recharge estimates were above average for the month, and groundwater levels started to rise at some of the key monitoring sites. Groundwater levels have made a dramatic turnaround since last October, when more than half the key sites had notably or exceptionally low levels for the time of year. Groundwater levels at Rockley in the Upper Kennet catchment are now the highest for the end of October since 1968. In 2011 levels at Rockley were the second lowest on record for October. Only groundwater levels at Stonor in the West Chilterns remain below the normal range for the time of year.

River Flows

River flows responded to the rainfall, saturated catchments and high groundwater levels. Some flood alerts were issued for the most responsive catchments, as well as a few related to high tides combining with high river flows on the Thames. A total of 24 fluvial flood alerts were issued, but no flood warnings. River flows at most of the key sites in this report had higher than normal flows for October. The Coln at Bibury had the highest October flows on record, again in contrast to last October when it had the second lowest on record. River flows in the west of the region were higher for the time of year than those in the east.

Reservoir Storage/Water Resource Zone Stocks

Reservoir storage was above or close to average for the time of year, with many of the online reservoirs close to capacity.

Full report is available at

http://www.environment-agency.gov.uk/static/documents/Research/SE_regional_monthly_water_situation_report.pdf