Fresh water

Fresh water is water that has only a small amount of salt in it. It is different from seawater, which has a lot of salt. Fresh water comes from places like rivers, lakes, wetlands, and underground sources. It is very important for plants, animals, and humans to live.

Only a tiny part of Earth’s water is fresh water—less than 3% of all the water on our planet. Much of this fresh water is frozen in places like Antarctica. Only a small amount is available for people to use. Fresh water is needed for drinking, growing food, and many other things that people do. It can become dirty or hard to find if we do not take care of it.

Fresh water is part of Earth’s natural water cycle. Water goes up into the air from oceans and lakes, makes clouds, and then falls back to the land as rainfall or snowfall. This cycle helps to keep our fresh water supplies full. But if people use too much fresh water, problems like not having enough water can happen. In some places, people find ways to make seawater safe to drink or reuse water, but these ways can cost a lot of money and need a lot of energy.

Definitions

Fresh water is water with very little salt in it—usually less than 500 parts per million.

Fresh water can be found in many places. It can be still, like in ponds, lakes, swamps, and mires. It can also flow, like in rivers and streams, which are called lotic systems. Fresh water can even be hidden underground, moving through rocks in places called aquifers. There's also a special area under big rivers, called the hyporheic zone, that holds a lot of water.