UK aquifers robust despite driest July on record

Groundwater is a critical water source in the UK. Across England it provides around a third of the overall public water supply and as much as 100 per cent in some communities in south-east England and East Anglia, which are underlain by chalk and limestone aquifers. Groundwater can also be a vital tributary to streams and rivers, helping to maintain water levels and important habitats.

Research conducted by scientists at the British Geological Survey (BGS) has highlighted groundwater’s remarkable resilience to extreme weather events against the backdrop of 2026’s record-breaking summer in terms of meteorological and hydrological drought.

The latest groundwater analysis reveals the status of aquifer levels around the UK at the end of July 2026. Remarkably, despite two-thirds of England and Wales being declared in drought, the general health of groundwater resources around the country is robust and, in some cases, higher than the normal historical levels. The data shows that groundwater levels are now stabilising after a period of declining and, while some levels are lower than in a normal year, there are no record low levels at this stage. Only a handful of sites are close to the lowest end of the historical average.

The study analysed 36 borehole monitoring sites around the country, specifically chosen for their location in the country’s major aquifers but away from external factors that might artificially impact natural water-level readings, such as abstraction sites. This baseline observation network benefits from a long-term data record, providing crucial contextual information for comparison. Each of the sites boasts groundwater records spanning a minimum of several decades and, in the case of Chilgrove House in West Sussex, almost 200 years.

Of the 35 groundwater sites with data featured in the latest report, only eight (23 per cent) are showing notably below normal levels, while 15 (43 per cent) are actually reporting normal or above normal levels compared with historical measurements for this time of year. None are currently showing record lows.

Scientists have long known that groundwater is a naturally resilient water source. While surface water resources often grab the headlines as they are such a visual reference point, groundwater is often overlooked as one of the country’s primary water sources. The extreme weather conditions this summer have really highlighted how robust these reserves are and indicate that they could play a much bigger role in mitigating the impacts of climate change in future.

Alan MacDonald, BGS head of Groundwater

The health of aquifers in comparison to surface water resources across North Wales, the Midlands, East Anglia, Kent, Devon and Cornwall is particularly striking; all are regions that were recently declared in drought by the Environment Agency and Natural Resources Wales — Cyfoeth Naturiol Cymru.

It’s remarkable in the context that we’re having this extreme heatwave, but groundwater is doing okay. Groundwater systems are a little bit more resilient to drought, but there is going to have to be more clever ways of managing through these droughts, and the water industry is aware of that and is working towards how we adapt. There are possibilities to more cleverly think about where you pump groundwater to minimise the impacts on summer low flows, whilst also maintaining public water supply.

Dr Christopher Jackson, BGS head of environmental modelling

The data highlights that, subject to careful management, groundwater has the potential to play a larger role in enhancing national resilience to periods of extreme weather. Groundwater augmentation schemes are already underway, such as the Environment Agency initiative in the River Severn, which can access water from the Shropshire Groundwater Scheme in periods of dry weather. At full capacity, this can release up to 240 million litres of water a day to help maintain river levels and protect water suppliers and wildlife habitats. There may be an opportunity to revisit current groundwater abstraction targets, to ensure more drought-resilient groundwater supplies are made available during periods of drought in future.

Groundwater has many advantages over surface water reservoirs, including a natural ability to store excess rainfall during wet weather (known as recharge). It is important to acknowledge that groundwater levels this year are benefiting from a strong period of recharge over the winter months. In a year with a drier winter, groundwater levels may have been left more vulnerable to this especially dry summer. However, providing typical wetter weather associated with late autumn and winter months occurs again this year, then groundwater levels in many aquifers are forecast to remain within, or return to, the normal range.

BGS, part of UK Research and Innovation (UKRI), is the national repository for groundwater data and information for the UK. The BGS-led groundwater analysis forms part of the wider, monthly Hydrological Summary published alongside data from the UK Centre for Ecology & Hydrology and the Met Office.

Further information about this research

Groundwater level data is provided to BGS’s National Groundwater Level Archive by the Environment Agency, Natural Resources Wales — Cyfoeth Naturiol Cymru, the Scottish Environment Protection Agency and, for Northern Ireland, the Department for Infrastructure — Rivers, and the Northern Ireland Environment Agency.

Earlier this year, BGS contributed scientific evidence to the Lords Committee report ‘Surviving drought, reclaiming the rain’ which calls for urgent action to improve drought planning and monitoring, invest in water storage infrastructure at all scales, reform abstraction licensing to increase flexibility, and engage in a whole of society approach to reducing water demand.