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 significantly above average in May, at 170% of the LTA. The preceding three months were all drier than average, and as a result groundwater levels have been declining. This decline has continued through May, although levels are still well above average for the time of year. This is due to the high rainfall received during the earlier part of the recharge period (October to January inclusive). Soil moisture deficit (SMD) has decreased as a result of the wetter conditions, and is now around average for the time of year. Predictions indicate that under all rainfall scenarios, levels are likely to continue to decline from this point, but are likely to remain above the LTA through the summer/early autumn. Under a 60% rainfall scenario or less, levels may dip below the LTA next winter.

The Chalk derived baseflow of streams across our Central region remains above average as a result of the high groundwater levels. Flows in most of the catchments across our Central region are currently classified as ‘normal’ or ‘above normal’ by the Environment Agency.