Will Paris and other cities run dry by 2050?

Cities are particularly vulnerable to these issues. On the one hand, rapid urbanisation and population growth place additional pressure on already strained water resources, while on the other hand, impermeable surfaces increase runoff and impede groundwater recharge. From Cape Town to Barcelona, São Paulo, Los Angeles, and London, cities worldwide are facing dwindling water supplies. In Barcelona, authorities even considered shipping drinking water to avoid disaster. In 2022, the source of the Thames dried up. By 2050, nearly two billion urban dwellers could face water shortages — a stark reminder of the urgency to adapt to climate change and disruptions in the hydrological cycle. This situation highlights the need to take action now to ensure sustainable access to water for all.

Long spared from water scarcity, the Paris metropolitan area is no longer immune. Since 1990, temperatures have risen by more than 2°C, accelerating evaporation and reducing soil moisture by 5%. As a result, the duration of droughts has increased by 20%.

Until 2025, the region has coped thanks to its infrastructure and a 14% reduction in water abstraction since 2012, driven by improved residential water management and the decline of heavy industries. In 2022, four large reservoir lakes supplied up to 50% of the Seine’s flow, preventing major disruptions — while navigation on the Rhine was halted.

However, these efforts may not be sufficient in the future.

By 2050, and even more so by 2100, summers will become drier. Evapotranspiration (the evaporation of water from soils and water surfaces, as well as the transpiration of plants) will increase by 16% by 2050 and 23% by 2100. This phenomenon will accelerate the drying of soils. This will lead to lower river flows, weakened groundwater tables, and a growing threat to water supply.

At the same time, water demand in the region is expected to rise, driven by demographic growth, reindustrialisation and the growing needs of agriculture, which has so far been relatively low in water consumption compared to other French regions.

In the face of these challenges, the issue of water resilience — defined as a system's ability to adapt to variations in water availability — becomes more urgent.

The OECD report “Adapting the Paris metropolitan area to a water-scarce future” estimates that a single drought episode could cost the Paris metropolitan area’s economy up to €2.5 billion. This amount is equivalent to the damage caused by Storm Xynthia in 2010 — one of the worst natural disasters France has ever seen. Agricultural and industrial losses could account for 70% of the costs, largely driven by production declines linked to water use restrictions and their ripple effects on value chains (such as transport and indirectly affected industries). Energy production, infrastructure and buildings would also be impacted.

Figure 1: Direct and indirect costs (due to their propagation to other sectors) in billion EUR 

Source: OECD (2025) “Adapting the Paris metropolitan area to a water-scarce future”.

Water scarcity could also heighten tensions between economic actors and authorities, particularly when cities draw water from rural areas for domestic use while agricultural abstractions are restricted.

Moreover, this estimate does not include the cost borne by ecosystems. Dry soils absorb less carbon, which exacerbates climate change. Wetlands and forests, which are crucial to regulating the hydrological cycle, would be severely affected. Lower river flows would also reduce the capacity to dilute pollutants.

To address these risks, the OECD recommends a combination of water demand management, diversified water supply sources, and a better focus on land use and its role in regulating the water cycle. Implementing these measures requires a detailed understanding of risks that considers both future needs and water availability.

However, these measures come at a cost, which must be shared by all stakeholders. Existing financial instruments that aim to increase the resilience of the region are already strained by climate change. This is the case for the national insurance scheme for natural disasters, whose expenses already exceed its reserves. Similarly, reducing abstractions will lower revenues for water operators, who play a key role in managing and adapting to water scarcity risks and building resilience.

In the face of these challenges, a new OECD report proposes an innovative method for assessing drought costs and a roadmap for ensuring the resilience of the Paris metropolitan area, drawing on international examples. The findings will be presented and discussed during a Green Talks LIVE webinar on 17 March at 15:00 CET. Find out more, register to join the webinar, or watch the recording once it is available.