The latest Environment Agency Water Situation report shows South East Region received below average rainfall during April whilst groundwater levels have reached their peaks and river flows remain normal or above normal.

12 months ago we were in a drought

Rainfall

The South East Region received 78% average rainfall for April, the 5th month with below average rainfall since April 2012. North East Thames area received the lowest average rainfall with just 58% average rainfall for April. Solent and South Downs area (SSD) recorded closer to average rainfall where 92% average rainfall for April was recorded. Much of the rain fell between the 9th and the 14th across the Region. The highest daily total of 25.2mm was recorded on the 13th at Duncton TBR in the Western Rother Greensand, SSD. The top 5 highest daily rainfall totals were all in SSD and greater than 20mm. The 10th was generally the wettest day in all of the other Areas, but no more than 16mm was recorded.

Soil Moisture Deficit

Recharge and Groundwater Levels Soil moisture deficits (SMDs) have risen during the month due to both the lower rainfall totals compared to previous months and the rising temperatures towards the end of the month. However, the model is currently overestimating SMDs due to the colder than average spring that has affected evaporation rates. This is currently under investigation and being re-modelled. Recharge has been correspondingly low due to the below average rainfall. Just one third of the average April effective recharge has been estimated this month. Groundwater levels range from notably high to below normal. Only 1 site, Jackaments Bottom in the Cotswolds, is below normal. This site reacts fairly quickly and as such has responded to the lack of rainfall. Groundwater levels at all of the other key sites appear to have reached their end of winter peaks and are now falling as is expected at this time of year. However, levels remain above normal for April since the previous 12 months were so wet. Stonor (Chilterns), Lilley Bottom (Lee Chalk) and Clanville Lodge Gate (Hampshire Downs) all remain the 4th highest levels for April on their respective records. There remain a number of groundwater flood alerts in force in West Thames area and SSD. They were issued in previous months but continue to be updated.

River Flows

The Rivers responded to the rainfall on and around the 10th and 13th. Flows at Broadlands (River Test) were the 3rd highest on record for April and flows at Bibury (River Coln), Eynsham (River Thames) and at Allbrook and Highbridge (River Itchen) have all recorded the 4th highest flows for 4 months ending in April. Only 7 flood alerts were issued in April across the Region.

Reservoir Storage/Water Resource Zone Stocks

Most reservoir storage remains at or above average for the time of year in the South East with the exception of Darwell reservoir in the Eastern Rother catchment.

Full report is available Here