page_title: Fresh water
section_title: Systems
hierarchical_section_title: Fresh water / Definitions / Systems
caption_attribution_description: English: Water fountain found in a small Swiss village. They are used as a drinking water source for people and cattle. Almost every Alpine village has such a water source. Français&#160;: Une fontaine dans un petit village suisse. Ces fontaines sont comme point d'eau, par les gens comme par le bétail. On en trouve dans tous les villages des Alpes.
context_page_description: Fresh water is any naturally occurring water except seawater and brackish water. Fresh water is generally characterized by having low concentrations of dissolved salts and other total dissolved solids. Though the term specifically excludes seawater and brackish water, it does include mineral-rich waters such as chalybeate springs.
  Fresh water may include water in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers, streams, and even underground water called groundwater.
  Water is critical to the survival of all living organisms. Some organisms can thrive on salt water, but the great majority of higher plants and most mammals need fresh water to live.
  Fresh water is not always potable water, that is, water safe to drink. Much of the earth's fresh water is to a substantial degree unsuitable for human consumption without some treatment. Fresh water can easily become polluted by human activities or due to naturally occurring processes, such as erosion.
context_section_description: Fresh water habitats are classified as either lentic systems, which are the stillwaters including ponds, lakes, swamps and mires; lotic which are running-water systems; or groundwaters which flow in rocks and aquifers. There is, in addition, a zone which bridges between groundwater and lotic systems, which is the hyporheic zone, which underlies many larger rivers and can contain substantially more water than is seen in the open channel. It may also be in direct contact with the underlying underground water.
  The majority of fresh water on Earth is in ice caps.
caption: Water fountain found in a small Swiss village; used as a drinking water source for people and cattle.
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 300D DIGITAL", "Image Orientation": "Horizontal (normal)", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS Windows", "Image DateTime": "2005:05:21 23:50:36", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "228", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1062", "Thumbnail JPEGInterchangeFormatLength": "6100", "EXIF ExposureTime": "1/40", "EXIF FNumber": "63/10", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2004:05:15 15:56:05", "EXIF DateTimeDigitized": "2004:05:15 15:56:05", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ShutterSpeedValue": "174389/32768", "EXIF ApertureValue": "174021/32768", "EXIF ExposureBiasValue": "-1/3", "EXIF MaxApertureValue": "162885/32768", "EXIF MeteringMode": "Partial", "EXIF Flash": "Flash did not fire", "EXIF FocalLength": "55", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1888", "EXIF ExifImageLength": "2841", "EXIF FocalPlaneXResolution": "768000/223", "EXIF FocalPlaneYResolution": "409600/119", "EXIF FocalPlaneResolutionUnit": "2", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard"}