By mid-August 2026, nearly 70 percent of France’s territory was under water restrictions due to a severe heatwave. The government estimated the economic cost of the heatwave to be between 10 and 15 billion euros. In Paris and its surrounding area, known as the petite couronne, water restrictions remained at a basic level of vigilance. However, several river basins in Seine-et-Marne, the Yvelines, and the Essonne had reached a higher level of alert, with some reaching the crisis threshold. A September report by the CCI Paris Île-de-France noted that the region’s water supply is currently secure but faces vulnerabilities in the medium term. Many companies, however, do not view this as an urgent issue, often seeing water as an artificially abundant resource. The Seine River, which flows through the heart of Île-de-France, has the lowest flow rate among France’s major rivers, averaging about 480 cubic meters per second. This is significantly lower than the Loire, which averages 900 cubic meters per second, and the Rhône, at 1,700 cubic meters per second. During the summer, up to 60 percent of the Seine’s flow in Île-de-France comes from four large reservoirs located upstream. This means that the river, which supports a region responsible for nearly a third of the country’s wealth, relies in part on stored water. Additionally, the quality of the river’s water is deteriorating, with only 24 percent of watercourses in the Seine-Normandy basin in good ecological condition, down from 32 percent in 2019. Despite these challenges, water restrictions are still relatively rare, and water prices remain close to the national average. Daily life in Paris continues largely unaffected, reflecting the city’s motto of enduring hardship without collapse. However, projections from the OECD indicate that the region has experienced an average of 110 days of soil drought annually between 1991 and 2020. Under the most unfavorable scenario, this number could rise to 150 days per year by 2040. The economic impact of such conditions could reach approximately 1.4 billion euros by 2050. A survey conducted in June and July 2026 by the CROCIS among 163 businesses in Île-de-France highlights a concerning lack of awareness. Two-thirds of the respondents did not consider water a pressing issue, and 65 percent had no idea of their annual water consumption. Nearly two-thirds had never identified their most water-intensive operations, and more than 40 percent believed they were independent of the resource. Yet, 38 percent acknowledged that water scarcity is the most critical risk for their business. This suggests a significant gap in how companies perceive and prepare for water-related challenges. The lack of awareness can be attributed to the structure of the Île-de-France economy, which is dominated by services and uses water mainly for sanitation and cleaning. Like electricity before 2022, water is often treated as a utility whose cost is not closely monitored. In shared buildings, many businesses do not have individual water meters, making it difficult to track usage. However, the dependence on water extends beyond the tap, affecting suppliers, energy providers, and digital infrastructure. The region hosts over 213 data centers, a third of France’s total, many of which rely heavily on the potable water supply. As a result, even businesses that consider themselves water-efficient may unknowingly support major water consumers. The CCI Paris Île-de-France is advocating for a culture of water risk awareness and the development of continuity plans that account for scarcity. While these measures are not radical, a 2024 survey found that less than 10 percent of small and medium-sized industrial businesses in the region had seriously evaluated their vulnerability to climate change. It remains to be seen whether these businesses will recognize the threat of drought before it becomes a reality.