Water level

This article is about the elevation level of the surface of water. For the device of the same name, see Water level (device). For the draft of a boat, see waterline. For other uses, see Water level (disambiguation).

Water level, also known as gauge height or stage, is the elevation of the free surface of a sea, stream, lake or reservoir relative to a specified vertical datum.^[1] Over long distances, neglecting external forcings (such as wind), water level tends to conform to an equigeopotential surface.^[2]

See also

• Water level (device), device utilizing the surface of liquid water to establish a local horizontal plane of reference
• Flood stage
• Hydraulic head
• Stream gauge
  • Water level gauges
• Tide gauge
• Level sensor
• Liquid level
• Reference water level
• Stage (hydrology)
• Sea level