We hear every day about the need to conserve freshwater. That goal seems sensible—although knowing if humankind is making any progress could be impossible without a reliable way to quantify how much water nations use.

To find out, engineers Arjen Hoekstra and Mesfin Mekonnen at the University of Twente in the Netherlands calculated the water footprint of the world’s countries as well as per capita water consumption in those nations.

Overall, the world is using 9,087 billion cubic meters of water per year. China, India and the U.S. consumed the highest annual totals: 1,207 billion, 1,182 billion and 1,053 billion cubic meters, respectively, followed by Brazil at 482 billion. But the water consumed per person in these and other countries varies considerably, due primarily to higher living standards or widespread waste among consumers. The U.S. had the world’s highest per capita water footprint, at 2,842 cubic meters per annum. Read more

Indore is the fastest-growing city in the central state of Madhya Pradesh, India. The industrial center has grown rapidly in the past 20 years, reaching a population of nearly 3.3 million people. But as the city grows in numbers, its water supply becomes increasingly insecure.

Like many cities in the developing world, Indore’s water infrastructure and institutions face the mounting pressures of population and growth and urbanization. Experts worry that global warming will compound these problems, enlarging a category of people they call the “water poor.”

To better understand the complexity of urban water systems in less developed nations, the Pacific Institute and the Institute for Social and Environmental Transition released a detailed analysis last week on the water situation in Indore. The three-year study involved downscaling climate models to the city level, performing a vulnerability analysis, and engaging with the community to come up with resilience strategies. Read more

The warming waters of one of central Europe’s most popular holiday destinations, Switzerland’s Lake Zurich, have created an ideal environment for a population explosion of algae including Planktothrix rubescens, a toxic cyanobacterium. It has the potential to harm humans, animals and the tourism that pumps up the economies of lake districts.

Although harmful algal blooms have been documented for more than a century, recently the number and frequency of cases have drastically increased.

According to research published in leading scientific journals, Lake Zurich is by no means alone. Cyanobacteria now threaten the ecological well-being of some of the world’s largest water bodies, including Lake Victoria in Africa, Lake Erie in the United States and Canada, Lake Taihu in China, the Baltic Sea in northern Europe, and the Caspian Sea in west Asia. They’ve also been found in Lake Kokotel in eastern Siberia, which is next to Lake Baikal, the world’s largest, deepest and most ancient freshwater lake. Baikal contains 20 percent of the world’s total unfrozen freshwater reserve. Read more

Whatever the latest food trend—chia seeds, coconut flour, kale chips—you’re on it. But you might be skimping on the most basic thing you can do for your health: chugging enough water.

“I see this happening a lot with busy women,” noted Dr. Pamela Peeke, a professor of medicine at the University of Maryland and author of “Body for Life for Women.” “They become so absorbed with work, answering e-mails and texting that they neglect to grab a water bottle.” Soon they’re parched and draggy.

Other signs of mild dehydration: muscle cramps, dizziness and headaches. Women who are even slightly dehydrated may find it harder to concentrate than those who aren’t, according to a recent study in The Journal of Nutrition. And if your body is regularly running low on water, you’re more likely to be constipated, too. Read more