As the world confronts the coronavirus pandemic, experts say that a key way to minimize the odds of getting sick is by washing your hands thoroughly and frequently. March 22 is World Water Day, designated by the United Nations to measure progress toward the goal of providing everyone worldwide with clean water for drinking and hygiene. Over the past 40 years, many nations have made great progress in treating wastewater, providing residents with clean drinking water and enhancing water supplies to grow needed food and fiber. But as a researcher focusing on water resources management and policy, I know there is still far to go. More than 40% of the world’s population lives in regions where water is becoming increasingly scarce, and that figure is likely to rise. Every day, nearly 1,000 children die from preventable water- and sanitation-related diseases. Water use has increased worldwide by about 1% annually since the 1980s, driven by population growth, economic development and changing consumption patterns. At the same time, water supplies are increasingly threatened by climate change, overuse and pollution. For example, in 2019 residents of Chennai, India, had to queue up for w...