As the first day of Autumn in the northern hemisphere lands on our leaf covered doorstep what is the current state of groundwater and what can we expect from the forthcoming recharge season?
Groundwater levels rise during autumn and winter with the highest groundwater levels typically observed at the end of Winter and start of Spring. Based on data presented by the Environment Agency we are in for a lower than average rainy season in the next couple of months having experienced the wettest August for 10 years across England.
Soil moisture deficits (SMD) have reduced as a result of the wet August and groundwater levels are reported as having decreased at all but two of the Environment Agency indicator sites, however remaining normal or higher for the time of year at all sites monitored. (SMDs is the difference between the amount of water actually in the soil and the amount of water the soil can hold expressed as a depth of water in mm).
The start of Autumn historically has meant low groundwater levels with the majority of recharge of the sub surface occurring over the next 6 months.
Reducing groundwater levels along with lower than average anticipated recharge is good news for those concerned about groundwater flooding allowing some time for the SMDs to improve in order to limit the potential impact of the higher Winter rainfall reducing the storage capabilities of the subsurface.
Here’s to a seasonal Autumn with just the right amount of recharge.