Wednesday, 18 November 2015

October 2015 overview

End of October soil moisture deficits were lower than average in the south of England
Groundwater levels, October 2015
reflecting the late summer 
rainfall, but above average in central and eastern England.  

Groundwater levels remained stable or continued their seasonal recession in the majority of index boreholes.

However, in the Chalk of south Dorset and the western South Downs levels at Ashton Farm, Compton House, West Woodyates Manor and Chilgrove House continued to rise (the last two by three metres) in response to recent recharge. Levels at Compton House and Chilgrove House rose to the normal range, whilst levels at Ashton Farm remained notably high. Elsewhere, levels fell in October and were generally average or slightly below at month-end, with the exception of Tilshead, Well House Inn, Dalton Holme and Wetwang which were notably low and Little Bucket Farm which rose to above normal. 

In the Jurassic and Magnesian limestones, levels fell or stabilised and were in the normal range. In the slower responding Permo-Triassic sandstones levels fell, returning to the normal range after four months of record high levels at Newbridge. Levels were average or above, with the exception of Llanfair DC which is notably low.

Levels in the rapidly responding Carboniferous Limestone boreholes of south Wales and the Peak District fell and were all below normal. Levels at Greenfield Garage fell from notably high at the end of September to below normal. 

For more information, see the Hydrological Summary for October 2015.

Hydrological Outlook from November 2015

The latest Hydrological Outlook is available.
Hydrological Outlook from November 2015

In the Chalk, levels in October were mostly normal or below. Notably low levels persisted in north-east England, while southern England saw a mixed pattern with some notably low levels in more central areas contrasting with above normal levels in parts of the far south. Levels in other aquifers were also mostly normal or below. 

The one month outlook indicates a similar pattern. For the three month outlook, below-normal levels are far less prevalent, with normal levels predominant across all aquifers and above normal levels possible in some localised areas. The shift towards normal levels again reflects the precipitation forecasts but, as with river flows, projections are highly uncertain.

Groundwater projections are particularly uncertain at this transitional time of year; late autumn and early winter rainfall will be highly influential on the longer-term outlook.