Groundwater levels

Central Region

*The long term average (LTA) has been calculated statistically, using the long term data record for this hydrograph. The respective drought zones are used as operational triggers, and have been derived using the LTA.

Rainfall in our Central region was well below average in April, at 46% of the LTA. Rainfall over the recharge period (October to March inclusive) has been 85 % of the LTA and effective precipitation over this period has been 68 % of the LTA. Conditions have therefore been drier than average, which has limited Chalk groundwater level recovery in the region. As a result of the dry winter, groundwater levels in our Central region are currently just below average for the time of year. Groundwater levels have plateaued through April and we are unlikely to see any further recovery until we reach the next recharge season in late 2022.

Groundwater levels are likely to decline from this point and have the potential to reach drought trigger 1. In accordance with our Drought Management Plan, reaching drought trigger 1 would mean we would start to consider and prepare for the possibility of the water resource situation becoming more serious. Under dry conditions (60-80% rainfall scenarios) drought trigger 1 could be reached in May. Under average conditions we could reach drought trigger 1 towards the end of summer this year. Above average rainfall scenarios (greater than 100% of LTA) will likely result in groundwater levels recovering to above the LTA later this year. Please refer to our Drought Plan for further information about droughts and how we manage them (Plans - Drought management plan - Affinity Water).

The continued below average rainfall through April has limited recovery of river flows in our Central region, and these are currently categorised as ‘normal’ or ‘below normal’ by the Environment Agency.