You encounter fresh water in a number of ways. From the tap water that comes out of your faucet to Siberia's pristine Lake Baikal, fresh water is an important part of the interworking of nature, societies and humanity. Although fresh water manifests in a variety of ways, there are two main types of fresh water: "Static" water, such as lakes and ponds, and flowing water, such as rivers and streams.
The Two Types
Static water, which comes primarily from lakes and ponds, is called lentic water. Flowing water, which comes from streams and rivers, is called lotic water. Although the terms lotic and lentic come from descriptions of larger bodies of water, these terms can also be applied to much smaller water formations. For example, water that comes out of the faucet is lentic, and water that forms a puddle on the floor is lotic.
Lotic Water Systems
Lotic water systems represent some of the most impressive and massive water formations in the natural world. The Rhine in Germany, for example, is the largest river system in the world in terms of volume, and it is a lotic water system. The Amazon, in South America, represents the second largest lotic water system. Other examples of lotic water systems include numerous waterfalls around the world, such as Iguassu Falls or Niagra Fall.
Lentic Water Systems
There are many lentic water systems around the world. The largest lentic water system in terms of volume is Lake Baikal in Russia, although Lake Superior in the United States has the greatest surface area. In addition to the numerous natural lentic systems, there are an abundance of man-made lentic bodies of water. For example, Norway's Acid Lake is a large man-made lake that features a variety of fish species and plants.
Although many people think of ponds, lakes, rivers and streams when thinking about fresh water, many scientists consider wetlands as a freshwater source. The term wetlands refers to swamps, bogs and marshes. These places may contain some salt in the water, but any body of water that has less than 1 percent salt content is considered to be fresh water. For example, Florida's Everglades and parts of California's Central Valley are examples of fresh water marshlands.