- Introduction
While recent focus on Europe’s energy vulnerabilities has come from Russian imports and geopolitical instability in the Middle East, a closer threat has been quietly emerging from the consequences of climate change. As a result of the rising temperatures and increasingly frequent periods of drought across Europe, water levels have decreased dramatically, putting energy production and fluvial trade routes under strain. In August 2026, Romania was forced to shut down its Cernavodă nuclear plant for the first time since 2003, after the Danube’s flow fell below the threshold needed for reactor cooling, despite infrastructural efforts to redirect water to the plant. Hungary’s only nuclear plant, which usually provides about half of the country’s electricity, is currently running at 25% capacity, and was close to suffering the same fate as its Romanian neighbor in the Danube, if it weren’t for emergency engineering. Over in Germany, the Rhine’s gauge fell to its historic low, restricting trade flows through ships in the region; while France, which produces 70% of its electricity through nuclear power, was forced to cut its production by 20% due to extreme droughts in the country.
Although the effects of climate change are often discussed around environmental preservation, health concerns or agriculture, the extreme droughts experienced in Europe expose an urgent risk to energy security and trade, with consequential effects for economic growth. The EU’s ambitions on low-carbon energy production and cross-border supply chains foundationally depend on water being available at a predictable level. However, extreme weather conditions, which have become increasingly recurrent, have shown that this assumption no longer holds under the effects of climate change. Monitoring by the European Drought Observatory (EDO) has shown that roughly half of the EU’s and UK’s territory experienced drought in July 2026, which is expected to persist until September this year. Extended periods of drought have been a recurring pattern in recent years, with 2026 surpassing figures from the worst years on record, such as 2018 and 2022, fuelling concerns over worsening droughts in the coming years.
Combined Drought Indicator for late July 2026, 2022 and 2018. Source: European Union, Copernicus EMS, European Drought Observatory, 2026.
This brief examines how the effects of extreme heat and drought expose critical vulnerabilities across Europe’s energy security and trade systems, and what these challenges imply for the EU’s work on climate adaptation, mitigation and water governance. We argue that the threats to power generation and trade through fluvial routes confirm that water scarcity represents an urgent cross-sectoral risk for Europe, while the current EU instruments lack efficient management for acute drought crises. This brief introduces the critical evidence from summer 2026 in Section II, the policy implications for energy and trade governance in Section III, and concludes with targeted policy recommendations in Section IV.
- The impact of the 2026 droughts
Following droughts since spring 2026, Europe’s four major rivers: the Loire, Rhine, Po and Danube, have hit record August low levels. Water proves to be a crucial factor in energy generation, as it is present at some stage of generation or operation in all existing electricity generating systems. When it comes to nuclear power production, plants need a constant supply of water to carry the heat away from reactors and cool the steam used to spin the turbines that generate electricity. Thus, plants can draw water from a river or sea and release it slightly warmer. A reliable source of water proves to be essential, as environmental rules limit how warm the returned water can be. During the spring and summer periods of extreme heat and drought experienced in Europe, if waters are too low or hot even before the process of cooling, nuclear plants have to cut production to stay within regulated frameworks. France’s nuclear power generation was affected by this exact issue. As data released by the Électricité de France (EDF) shows, nuclear production fell by about 9% in June due to high temperatures, and during August, nuclear facilities were operating at 80% capacity because of jellyfish clogging cooling systems and restrictions from ecological thresholds. These drastic cuts in recent years are far away from the historical norm. The EDF noted that since 2000, high temperatures and low river flows have only represented a 0.3% annual loss of nuclear power generation in France. Thus, recent alarming figures underscore the urgent risk climate change poses to energy security. In coming years, it will become more recurrent for energy systems to suffer the same fate as Romania’s nuclear fleet, as the Cernavodă plant, which supplies a fifth of the country’s electricity, was forced to shut down in August, leading the government to request consumption cuts to its own citizens and slash production across major manufacturers.
Due to water’s existential role in power generation, the impacts of rising temperatures extend beyond nuclear power generation into hydro- and thermal-power, with consequences visible across Europe. Serbia reduced power generation at its two biggest hydroelectric plants, in Italy the Po basin underwent serious hydrological stress, and the Vistula River hit an all-time low in Warsaw, leading to the shutdown of sections of two coal-fired power plants. Moreover, the Rhine’s low water levels crucially impact trade within continental Europe, as vessels crossing the river have been restricted to carry 20% of their conventional cargo capacity. Trade through the Danube has also suffered from several delays, with vessels not being allowed to travel fully loaded either. This has led to an unexpected shift towards rail and road transport, increasing shipment costs, as companies are forced to use up to 150 trucks for a single barge.
Electricity and trade costs are already piling up across European economies, and threaten to become more costly with the effects of climate change on water systems. The disruptions in the Rhine are expected to cut Germany’s economic output by 0.2% in Q3 of 2026, while Triodos Bank estimates that the effects of extreme heat and drought could erase up to 1 percentage point of the EU’s economic growth in 2026 (approx. €180 billion).
3. Discussion
The temptation is to read 2026 as a “bad summer”: hot, dry, unlucky. Nonetheless, the data contradicts that framing. The Joint Research Centre (JRC), which provides evidence-based scientific advice to support EU policies, compared severe-drought years and found a clear trend of worsening severity. In 2018, alert-level drought affected 6% of monitored European territory by the end of August. In 2022, that share peaked at 18% in mid-August. By 2026, drought conditions have intensified further, with alert-level drought spreading across France, southern Germany, UK, Switzerland, northern Italy, and the entire Danube basin as early as July.
Here, the trend line, not the individual year, is the story: each “record” summer is quietly resetting the floor for the next one, and scientific analysis of climate drivers confirms the mechanism: climate change made the 2026 drought roughly 80 times more likely in western Europe and 40 times more likely in eastern Europe. Therefore, seeing 2026 as a one-off could leave Europe unprepared for a future of more frequent and severe droughts.
The challenge becomes most visible when countries share resources. The Danube is the clearest case study: five states affected draw on the same river, yet each manages water based on its own needs. For instance, Romania’s decision to remove rocks from the riverbed to protect water levels at Cernavodă helped secure its own water supply but could affect flows that neighbouring countries also rely on. As Birgit Vogel, executive secretary of the International Commission for the Protection of the Danube River (ICPDR), advised: “drought management across the Danube needs improvement”. Despite repeated calls for closer coordination, there is still no single binding policy governing water scarcity across the river basin. Responsibility remains divided between national governments and river authorities, leaving countries able to protect their own interests even when this may affect their neighbors.
Nuclear power adds a second layer of tension, because it complicates Europe’s own decarbonisation story. A technology sold as stable, low-carbon baseload turns out to carry a hidden climate risk. Its cooling capacity can fail during periods of extreme heat and drought, precisely when demand for electricity to power cooling is at its highest. EDF has responded with an €8.7 billion adaptation programme running through 2040. Nonetheless the timing is revealing. The investment came only after several summers of actual shutdowns, rising from around €600 million to €8.7 billion in just three years. This shows that the nuclear fleet was not designed for the climate it now faces. Instead, it is being adapted reactor by reactor, while shutdowns continue in the meantime.
The final gap is one of political priority. Since 2022, gas pipelines and electricity grids have been treated as critical infrastructure, with binding EU targets and emergency measures. Rivers, even though they also support essential services such as cooling power plants, generating electricity and transporting goods, have not received the same level of protection. The EU’s Water Resilience Strategy aims to change this by extending critical infrastructure and cybersecurity rules to the water sector from 2025. Yet, the strategy lacks binding targets, dedicated funding and strong enforcement. The European Commission estimates that around €23 billion a year is still needed to implement existing EU water laws. Gas shortages led to REPowerEU, with clear targets, deadlines and emergency measures. By contrast, water scarcity has so far led to a strategy without the same level of binding action.
4. Conclusion
Cernavodă’s shutdown, Paks running at a quarter of capacity, record-low water levels on the Rhine, and a 20% cut in French nuclear output may look like four separate stories. They are not. Together, they show the same problem across Europe: energy and trade systems were built on the assumption, as it should be, that water would remain reliable, but that assumption is no longer holding. The pattern seen in 2018 and 2022 shows that 2026 is not a one-off event. Yet, Europe’s current response remains largely national, reactive and voluntary, not enough for a risk that is becoming increasingly frequent.
Three steps could address the biggest gaps. First, water stress should be included in EU and national energy security assessments, just as gas supply risks already are. A low-Rhine summer should trigger the same level of concern as a major gas supply disruption. Second, cooperation at the river-basin level needs to be stronger. Giving the ICPDR binding powers during drought emergencies could replace the current system of countries acting unilaterally with a shared set of rules that all countries can rely on. Third, the EU should continue investing in renewables such as wind and solar, which do not require cooling water, while also helping fund upgrades to vulnerable nuclear and hydropower plants. This support should come through existing Water Resilience Strategy funding, rather than leaving utilities such as EDF to pay for adaptation on their own after problems occur.
One challenge still needs more attention: EU-wide data on water use remains fragmented across countries and sectors, making it harder to assess risks across entire river basins. Closing this data gap is essential to move from reacting to droughts to preparing for them.
Cernavodă was forced to shut down not by war or a fuel shortage, but by a river running dangerously low. Until water is treated as seriously as gas in Europe’s energy planning, it may not be the last.
References
American Nuclear Society. (2026, August 14). Cernavoda, Paks, Gravelines plants suffer as European heat wave impacts water sources. Nuclear Newswire.
Blackburn, G. (2026, August 13). Romania shuts off second reactor at Cernavodă NPP amid low water levels on Danube. Euronews.
Blackburn, G., & Duchêne, S. (2026, August 12). Extreme weather and jellyfish knock one-fifth of France’s nuclear capacity offline. Euronews.
Bloomberg News. (2026, August 11). Rhine River at record low levels is forcing industry to react. Bloomberg.
BNN. (2026, August 24). The Danube is drying up; Europe has no plan. BNN.
Connor, R. (2026, August 11). Germany: Low Rhine river levels could push economy into stagnation. DW.
Copernicus Emergency Management Service. (n.d.). Drought observatories. European Commission.
Delille, T. (2025). The European Commission’s 2025 Water Resilience Strategy: Emerging regulatory landscape and implications for businesses. Squire Patton Boggs.
Eagle Intelligence Reports. (2026, August 13). Heat and drought strain Europe’s energy and trade. Eagle Intelligence Reports.
European Union. (2026, August 5). Europe’s major rivers at record low water levels. EU Space Support Office.
IN Power. (2026, August 7). EDF assigns €8.7bn to French generation resilience. Electrical News.
International Commission for the Protection of the Danube River. (2025, March 12). ICPDR Executive Secretary calls for stronger coordination in drought management across the Danube Basin. ICPDR.
Joint Research Centre. (2026, August 12). Worsening drought and record heat grip Europe, fuelling extraordinary wildfires and extremely low river flows. European Commission.
Katanich, D. (2026, July 13). France shuts down nuclear reactors as heatwave intensifies. Euronews.
Kumar, Y. (2026, August 5). France cuts over 5 GW of nuclear capacity as drought, heat trigger reactor shutdowns. Industrial Info Resources.
Pietrani, H. (2026, June 13). EDF will spend nearly 9 billion euros to adapt to climate change. Revolution Énergétique.
Snelson, B. (2025, June 4). Not flowing, not funded: EU Water Resilience Strategy falls short. European Environmental Bureau.
Triodos Bank. (2026, August 8). Europe’s extreme heat could wipe out EU growth in 2026. Triodos Bank.
Weiss, P., & Steitz, C. (2026, August 12). Low Rhine levels disrupting German industry. Global Banking & Finance Review.
World Nuclear Association. (2026, August 24). Cooling power plants. World Nuclear Association.
