Will there be a drought in 2011?

Dried up Chalk bourne, by Andrew Newell, copyright NERC 2003

A dried up Chalk stream during 2003 drought.

Groundwater scientists in BGS are watching groundwater levels across the country closely.
A relatively dry winter and a very dry early spring in many parts of the UK mean that groundwater levels are low in some areas. But will there be a drought? And why is understanding our groundwater resource so important?

Our monthly review of groundwater levels across the UK for March shows that groundwater levels are significantly below average for many sites across the Midlands and the west of the UK. For example, levels at Stonor Park borehole in Berkshire are about 7 metres below average for this time of year. Given the continuation of dry and unusually warm weather during April, there is unlikely to be any significant recovery of groundwater levels before next autumn.

If the dry weather continues groundwater levels can only decline further.

Stonor Park groundwater hydrograph, March 2011. Black line shows measured groundwater levels, pink line shows long term monthly average groundwater level. Blue envelope shows maxima; pink envelope shows minima.

Why is groundwater important during droughts?

Groundwater is widely used for water resources in the UK, and it becomes a critical resource during surface water droughts. Prolonged periods of dry weather lead to reduced river flows and falling reservoir levels, but groundwater levels take longer to fall.

As well as providing water for domestic, industry and agricultural use, groundwater helps to maintain ecologically important flows in many of our rivers during periods of drought. In these ways, groundwater provides the UK with resilience to droughts.

However, if we have long periods of reduced rainfall, particularly during the winter and early spring months as has occurred this year, then aquifers don't get replenished and groundwater levels can fall significantly.