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.

September and October received rainfall that was in excess of 130 % of the LTA and this wet weather has continued into November. Up until Tuesday inclusive, we have had 55 % of the monthly LTA rainfall total and 81 % of the monthly LTA effective precipitation total, whilst soil moisture deficit (SMD) remains below average. This will increase the recharge component of further rain that falls. Groundwater levels have responded to this rainfall in most of the Central region Chalk and have increased slightly, ahead of the LTA trend; at Lilley Bottom this has resulted in groundwater levels climbing out of drought zone 3. Note though, that in indicator boreholes that are reflective of the more slowly responding Chalk in the North and East of the region (Elsenham Nurseries), levels are still declining and may enter drought zone 3 this month.

Flows in most rivers have responded to the rainfall and groundwater recovery, although remain low for the time of year. We are currently supporting the River Cam, River Rhee and River Hiz. Continued above average rainfall is needed over the coming months to cause a sustained improvement in the groundwater outlook.