How is climate change reshaping Europe’s water supply?
Across Europe, droughts are becoming more frequent and severe. The continent is warming twice as fast as the global average and now faces the highest rate of water stress in the world.1 Thirty percent of Europeans already live with permanent water stress, and up to seventy percent face seasonal shortages.2,3 In early 2024, Catalonia declared a state of emergency when reservoirs dropped below 16 percent of capacity.4
These conditions are forcing water utilities to rethink how they manage every part of the network, starting upstream where water begins its journey. Our “From source to tap” series begins upstream with Business Development Director for water Martin Duff looking at how utilities can protect groundwater and reservoir resources to secure long-term supply, covering:
- The challenges facing groundwater supply
- Why reservoirs are under increasing pressure
- Why upstream action matters for the whole network
What are the challenges facing groundwater supply?
Groundwater abstraction, pumping water from underground aquifers, has long been one of Europe’s cheapest and most reliable sources of raw water. Natural filtration often reduces treatment costs. But climate-driven drought is slowing recharge rates, meaning less water enters these aquifers even as demand grows. In some regions, it can take thousands of years for water to replenish underground stores.
Building resilience through diversification
Reducing reliance on groundwater and developing multiple raw-water sources allows utilities to maintain supply without exhausting natural reserves. Desalination is emerging as a complementary option. The process removes salt from seawater, typically using high-pressure reverse osmosis (see Figure 1).
For example in the UK, South West Water is constructing a desalination plant in Cornwall to produce between 2.5 and 5 million liters of additional drinking water per day.5 By expanding options upstream, utilities can protect aquifers and create flexibility during dry seasons.
Figure 1: The reverse osmosis desalination process
Why are reservoirs under increasing pressure?
About 75 percent of Europe’s water comes from reservoirs,6 yet reservoir levels have dropped to record lows.7 In a warmer climate, more water is lost through evaporation and seepage through the reservoir base, worsening shortages when supplies are most needed.
Managing loss and efficiency
Some utilities are lining reservoirs with impermeable membranes to prevent
seepage, or deploying floating plastic spheres to reduce evaporation. Both techniques can be effective but are costly to install and maintain. A more sustainable approach is to reduce downstream demand through better leakage control and customer-side conservation. The less water required at the tap, the less needs to be stored upstream.
Why upstream action matters for the whole network
Protecting water sources is not only an environmental necessity, it underpins network stability. Every liter saved through improved reservoir efficiency or reduced groundwater extraction supports the security of downstream supply.
Atmos supports water utilities around the world with technologies that strengthen the entire network, from source to tap. As water stress intensifies across Europe, upstream investment is becoming as important as treatment or distribution.
Discover how Atmos can support utilities at every stage of the water journey
References
1 https://climate.copernicus.eu/esotc/2024
2 https://www.unwater.org/water-facts/water-and-climate-change
3 https://www.worldwildlife.org/threats/water-scarcity
4 https://earthobservatory.nasa.gov/images/152534/sau-reservoir-dries-up
6 https://water.europa.eu/freshwater/europe-freshwater/freshwater-themes/water-resources-europe