Article
The costs of climate are hiding inside Europe's water systems
Europe’s summer of 2026 exposed the growing climate-linked costs of maintaining safe and reliable water and sanitation services. Those costs will not be shared equally. Choices being made now will help determine who remains protected, which providers can adapt and whether water and sanitation services deliver their full benefits to people and the environment.
Across Europe, the summer of 2026 made water look different. Major rivers ran unusually low. Restrictions spread. Farmers, industries, inland transport, energy producers and households faced growing competition for water.
In Hungary, the consequences reached far beyond water supply. Record-low levels in the Danube reduced the cooling water available to the Paks nuclear power plant. In early August, the facility that normally provides around 40% of the country’s electricity almost had to be shut down. The shortage of water becomes an issue of national energy security requiring rapid action to find a quick solution (Bloomberg, 2026 cited in Energy Connects). The rapid construction of a water weir helped to keep water at reasonable levels. Fortunately, this solution worked and at the last minute the water levels increased sufficiently to avoid total shutdown. However, it has been a major investment that has led to environmental concerns (Hungary Today, 2026).
This was a dramatic example of a much wider dependence. The same rivers that provide drinking water also support energy production, industry, agriculture, transport and ecosystems. When water levels fall, pressure passes rapidly from one system to another.
On 12 August 2026, the European Commission Joint Research Centre reported record-low August levels in the Loire, Po, Rhine and Danube. Half of the territory of the EU and UK was experiencing some level of drought in late July. Water resources, agriculture, energy, river transport, tourism and ecosystems were all under pressure (European Commission Joint Research Centre, 2026).
Drought and extreme heat were the immediate causes. But they were only part of the story. The summer also exposed differences in the capacity of Europe’s water and sanitation systems to respond.
Europe has extensive water and sanitation infrastructure. Yet not everyone benefits from it equally. Neither is every provider equally able to protect those benefits as conditions change.
The costs of summer 2026 cannot therefore be measured only through lost crops, disrupted shipping or reduced energy production. Part of the costs are covered within the systems that provide water, manage wastewater and protect public health.
Some costs will be visible in utility investment, public spending and household bills. Others will appear gradually through additional treatment, postponed maintenance, environmental damage or declining reliability.
The question is not only how much climate change will cost Europe’s water sector. It is who will bear those costs, who will remain protected and who may be left behind.
Who is excluded?
We have identified four distinct scenarios of exclusion in which Europeans are not having such access to safe water and sanitation services:
Scenario 1 — Social and economic exclusion within served areas. Marginalised communities or very low-income households living within areas a utility otherwise serves well, but who are excluded — or remain at risk of losing access — for social or economic reasons.
Scenario 2 — Geographic exclusion. Households not reached by, or receiving an inherently inadequate service from networked utilities because they are geographically remote — reliant instead on self-supply or small community-managed systems that cannot achieve a networked utility's economies of scale.
Scenario 3 — Potential future exclusion.
Populations and areas currently well served, but by providers with structurally limited financial, human or technological capacity to adapt to emerging threats — climate change, ageing infrastructure, resource depletion. All of Europe faces future threats to supply; the scenario of concern here is specifically where the provider lacks the capacity to respond, not the hazard itself.
Scenario 4 — Exclusion from the environmental and public-health benefits of services.
Populations who have access to a service — e.g. a sewer connection — but where the service does not deliver its intended downstream benefit, for instance because wastewater is inadequately treated before discharge to a river.
From emergency response to inclusive resilience
Europe will need to spend more on its water future. Five priorities stand out.
1. Make the hidden costs visible
Governments, regulators and providers need a clearer picture of what drought, heat, flooding and deteriorating water quality add to operating expenditure, capital requirements, household costs and environmental damage.
Without that evidence, the costs of inaction remain easy to overlook or transfer to future customers and taxpayers.
2. Identify who is at risk
National access figures can conceal households facing financial and administrative barriers. They can also overlook remote communities relying on small supplies and populations served by providers with limited capacity to adapt.
Resilience planning should assess vulnerability among both users and providers.
3. Strengthen weaker providers
Investment in infrastructure should be accompanied by technical support, institutional development, monitoring and sustainable financing.
Consolidation may be useful in some places. Shared technical services or professional support for small operators may be more appropriate elsewhere. The arrangement matters less than the outcome: a safe service that can be sustained as conditions change.
4. Build affordability into adaptation
Targeted financial support, simpler administrative arrangements and proactive engagement with marginalised communities should be designed into climate programmes from the beginning.
If adaptation costs are recovered without considering affordability, measures intended to protect services could deepen exclusion.
5. Follow sanitation to the end of the chain
Connections alone are not an adequate measure of success. The real test is whether wastewater is safely managed and whether people, rivers and ecosystems receive the intended benefits.
Monitoring and public information can improve accountability. But evidence must lead to action by providers, regulators and governments.
So what can we all do?
Different places will need different combinations of these approaches. There is unlikely to be one model for the whole of Europe. More evidence is needed about what works, how it can be financed and which institutional arrangements can be adapted elsewhere.
But the direction is becoming clearer.
Europe cannot prevent every drought, flood or heatwave. It can improve the systems that determine how their consequences are shared.
Riva, under its new vision, is seeking to develop a strategy for our activities in Europe. We would be delighted to hear from colleagues interested in collaboration in research and innovation that effectively take local actions up to change policies at country and European level.