World Water Day

What Is World Water Day?

Every March 22nd is "World Water Day." It was proposed in "Agenda 21," the action plan of the "Earth Summit" (UN Conference on Environment and Development) held in Rio de Janeiro, Brazil, in June 1992, and was decided by the UN General Assembly in December of the same year. One of the UN's international days, it has been observed since 1993. It is a day for people worldwide to think about the value of water resources and the importance of access to safe water. Of all the water on Earth, the fresh water that people can readily use, such as rivers and lakes, is only a tiny fraction.

Earth's Water Resources

Water is at the heart of the cycles that support life on Earth.

• The water cycle: Water evaporated from the sea and land by the sun's heat forms clouds, falls as rain or snow, and returns to the sea through rivers and groundwater. Because this cycle repeats, we can keep using water.
• Properties of water: Within familiar temperatures, water takes three forms: liquid, solid (ice) and gas (water vapor). It also heats up and cools down slowly, so the oceans help moderate changes in Earth's temperature.

The World's Water Problems

Access to safe water is fundamental to a healthy and dignified life.

• Safe drinking water: According to a 2025 WHO/UNICEF report, about 2.1 billion people worldwide (1 in 4) still lack access to safely managed drinking water.
• Virtual water: This concept estimates how much water would have been needed if imported farm products and manufactured goods had been produced domestically. Materials from Japan's Ministry of the Environment say that producing 1 kg of beef requires about 20,000 liters of water, so Japan, which imports much of its food, can be said to depend on water overseas as well.

Fun Facts About Water

• Breaking down the "water planet": About 70% of Earth's surface is covered by water, but about 97.5% of Earth's water is seawater, and much of the fresh water exists as glaciers and groundwater.
• Water in the body: About 60% of an adult's body is water. Losing even a little of it is enough to make you feel thirsty.
• Hard and soft water: Water is classed as hard or soft by the amount of calcium and magnesium it contains. Most of Japan's tap water is soft, which is said to bring out the flavor of dashi and tea.
• Japan's "Water Day": In Japan, August 1st is "Water Day," and August 1st to 7th is "Water Week."

Tips for Marking World Water Day

• Find out which river or dam supplies your home's tap water
• Try one way to save water, such as turning off the tap while brushing your teeth
• Check the label of the mineral water you usually drink for its hardness and source
• Check how much emergency drinking water you have stored and its expiration date

Thinking About the World's Water Beyond the Tap

Safe water flowing from the tap is not something everyone in the world can take for granted. March 22nd is a day to think about where the water we use every day comes from, and about the state of water around the world.