The Different Types of Water


Fresh water

  • is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Freshwater is defined as having a low salt concentration - usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration. Water is a critical issue for the survival of all living organisms. Some can use salt water but many organisms including the great majority of higher plants and most mammals must have access to fresh water to live.The use of water by humans for activities such as irrigation and industrial applications can have adverse impacts on down-stream ecosystems. Chemical contamination of fresh water can also seriously damage eco-systems. Fresh water is a renewable and variable, but finite natural resource. Fresh water can only be replenished through the process of the water cycle, in which water from seas, lakes, forests, land, rivers, and reservoirs evaporates, forms clouds, and returns as precipitation. Locally however, if more fresh water is consumed through human activities than is naturally restored, this may result in reduced fresh water availability from surface and underground sources and can cause serious damage to surrounding and associated environment.

Brackish Water

  • is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. Certain human activities can produce brackish water, in particular certain civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment. Brackish water condition commonly occurs when fresh water meets seawater. In fact, the most extensive brackish water habitats worldwide are estuaries, where a river meets the sea.

Salt Water

  • is water from a sea or ocean. Salt water is denser than both fresh water and pure water (density 1.0 g/ml @ 4 °C (39 °F)) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of salt water decreases as salt concentration increases. At typical salinity, it freezes at about −2 °C (28 °F).[1] salt water is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths or near melting glaciers, salt water can be substantially less saline. The most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and river inflow, and confined circulation result in unusually salty water. The salinity in isolated bodies of water can be considerably greater still. Accidentally consuming small quantities of clean seawater is not harmful, especially if the salt water is taken along with a larger quantity of fresh water. However, drinking salt water to maintain hydration is counterproductive; more water must be excreted to eliminate the salt (via urine) than the amount of water from the salt water itself.