By Kuba Gogolewski, Program Director of the Mission Possible Foundation
The scorching heatwaves at the end of June provided a stark preview of the extreme temperatures our society and economy must learn to adapt to. On Sunday, June 28, Poland hit a historic milestone when the town of Słubice, on the German border, recorded an unprecedented 40.5°C.
While this intense heatwave was relatively short-lived in Poland, other European nations, like France, were not as fortunate. The World Meteorological Organization (WMO) warned that the recent European heatwave behaved like a system typical of late July or August, rather than June. All signs indicate that we must brace for more frequent and intense heatwaves in the weeks and months ahead.
The Vicious Cycle of Dry Soil
Extreme heat rapidly desiccates the ground, stripping the soil of moisture and stunting vegetation. When rains do follow these heatwaves, they are typically heavy and torrential. Consequently, the water quickly runs off into rivers rather than being absorbed by the parched earth and retained by plants.
This dry ground triggers a dangerous feedback loop. When the soil is moist, solar energy is first spent evaporating that moisture, which naturally cools the ambient air temperature. When the soil is bone-dry, that solar energy directly heats the air instead, intensifying the next influx of hot air.
The Twin Threat: Hydrological and Hydrogeological Drought
Extreme heat exacerbates both hydrological drought (low river and lake levels) and hydrogeological drought (the dropping of the underground water table). These underground reserves are what sustain Poland’s rivers and lakes during the long, dry periods of the year when there is no rain or snowmelt.
Heatwaves accelerate evaporation from rivers, simultaneously lowering their water levels and spiking their temperatures. Poland has not yet reached the crisis level of Hungary, where on June 29, the Paks Nuclear Power Plant was forced to curtail generation after Danube water temperatures hit 30.2°C. However, data shows our rivers are heating up rapidly. On July 1, 2026, after less than a week of hot weather, the Vistula River at the Zawichost measuring point reached 29°C.
This river depletion will be further compounded by an ongoing hydrogeological drought. In its latest outlook, the Polish Geological Institute (PIG-PIB) projects that groundwater levels – specifically the shallowest aquifers in direct contact with rivers, lakes, and ponds – will plunge to critical lows (“hydrogeological low flow”) across 14 out of 16 voivodeships in July 2026, sparing only Lubuskie and Warmińsko-Mazurskie.
According to the Central Statistical Office (GUS), groundwater accounts for 74% of the drinking water distributed via municipal grids in Poland. A prolonged groundwater drought threatens to disrupt public water supplies, particularly those drawn from shallow wells.
Water Temperature and Poland’s Power Grid
Water level and temperature are matters of operational survival for the Polish power grid, which remains heavily reliant on aging, highly vulnerable coal-fired units cooled by rivers or adjacent artificial reservoirs.
According to grid operator PSE, as of November 2024, the average age of Poland’s hard coal and lignite units was 37 years – a figure now rapidly closing in on 40 years. Units older than 40 years accounted for 45% of the country’s installed coal capacity.
Furthermore, gas-fired plants, biomass units, inland Small Modular Reactors (SMRs), and conventional nuclear plants all require vast quantities of cooling water. This drastically limits viable locations for new projects and leaves freshwater-cooled plants highly exposed to prolonged heatwaves and rising river temperatures.
We saw this play out on the final day of June. Spurred by heatwave-driven air conditioning use, electricity demand spiked just as coal-fired units at the Turów and Ostrołęka power stations, alongside the Żerań CHP plant in Warsaw, suffered thermal outages.
Faced with these failures, PSE was forced to trigger its Emergency Demand Response mechanism under the capacity market for only the third time in history to keep the grid stable. The crisis was worsened as the Kozienice Power Station had to curtail its output due to high water temperatures in the Vistula, making it impossible to safely cool the plant.
A Toxic Two-Way Relationship
While thermal coal units are increasingly vulnerable to heatwaves, they also actively degrade aquatic ecosystems. The thermal discharge (warmed cooling water pumped back into rivers) artificially heats the waterways even further.
Thermal power plants – primarily coal-fired – are responsible for over half of all water withdrawals in Poland, a country already classified as water-scarce.
The “Water Saving” Argument for Wind and Solar
In 2024, industry and the energy sector withdrew 4.76 billion cubic meters of water – a massive chunk of Poland’s freshwater reserves, which drop below 40 billion cubic meters during dry spells. While GUS reports that overall water consumption has ticked down, much of this drop is directly tied to a decline in coal-fired generation (hard coal fell by 1.8 TWh or -3.0% year-on-year, and lignite by 2.6 TWh or -7.1%). This positive trend would be even more pronounced if closed coal units were not being routinely replaced with water-thirsty gas plants.
Every ton of coal we leave in the ground directly reduces our power system’s vulnerability to “energy droughts,” while keeping our air and water free of heavy metals and combustion byproducts.
A country facing chronic drought and limited water resources needs a transparent, synchronized strategy for both water and energy. Numerous studies – including reports from the European Commission’s Joint Research Centre and IRENA (highlighted by the World Economic Forum in 2026) – confirm that protecting freshwater systems requires a shift to wind (both onshore and offshore) and solar PV.
Every wind turbine and solar panel installed reduces the pressure on our national water supplies compared to thermal generation. Furthermore, electrifying our district heating systems allows us to use renewable power to displace the water-intensive mining of hard coal and lignite.
The Opportunity for Local Municipalities
By August 31, 2026, Polish municipalities (gminy) must adopt their new master plans (plany ogólne).
These plans should not only designate areas for local water retention to buffer future heatwaves, but also fast-track the zoning of onshore wind and solar projects. Embracing decentralized renewables is the single best way for local communities to secure both energy independence and water security during the hot, dry summers of our climate reality.