Wednesday, 24 June 2015

May 2015 overview

Recessions in groundwater levels continued during May, despite the wet conditions over much of the UK. Soil moisture deficits (SMDs) have become established in south-eastern areas, meaning rainfall is taken up by the soil rather than recharging aquifers. 
Groundwater levels, May 2015

Across most Chalk aquifers, levels remained normal although they declined at a slightly faster rate than is typical. In Yorkshire, Wetwang and Dalton Holme were notably low. Compared to April, more of the Wessex and Hampshire Chalk was below normal; notably low levels were recorded at Ashton Farm and Tilshead, which recorded its sixth lowest May level in 47 years. Only two Chalk boreholes (Therfield Rectory and Little Bucket Farm) recorded above normal levels – these boreholes continued to be influenced by the wet conditions of 2013/14. 

Elsewhere the situation was mixed. In south-west England and south Wales, levels remained normal. Levels in the Jurassic limestone were below normal in southern areas and nearer normal further north. Swan House, in the Magnesian Limestone, was an exception, recording below normal levels due to limited recharge this winter. 

Several Permo-Triassic boreholes remained at exceptionally high levels, the legacy of exceptional recharge in 2013/14, whilst others were close to their seasonal norms. An exception was Llanfair D.C. in north Wales, where levels were slightly below normal. 

Any moderation of recessions in the Chalk from a wet May was yet to show at month-end. Low levels in Wessex and Hampshire may persist through the summer or decline further, though still well above the minima of 2011/12.







For more information, see the Hydrological Summary for May 2015 [PDF].

Tuesday, 16 June 2015

Hydrological Outlook from June 2015

The latest Hydrological Outlook is available.



In the Chalk, May groundwater levels were mainly normal in the south-east, but levels were below normal (and notably low in some boreholes) in parts of southern England and Yorkshire. 

Levels were mixed in other aquifers, with exceptionally high levels persisting in parts of the Permo-Triassic sandstone. 

The one month outlook suggests a similar situation will continue in June, although levels in the Permo-Triassic are likely to be notably high rather than exceptional. 

The groundwater situation is unlikely to change significantly through the summer; the three month outlook suggests normal levels will dominate, but with below-normal levels persisting in parts of north-east and southern England (although there is a possibility that levels in some parts of Wessex may return to normal).

For further information see the full Hydrological Outlook for June.