[fresh-waw-ter, -wot-er]

Freshwater is a word that refers to bodies of water such as ponds, lakes, rivers and streams containing low concentrations of dissolved salts and other total dissolved solids. In other words, the term excludes seawater and brackish water.

Freshwater is an important renewable resource, necessary for the survival of most terrestrial organisms, and is required by humans for drinking and agriculture, among many other uses. The UN estimates that about 1.2 billion people (18 percent of the world's population) lack access to safe drinking water.

Numerical definition

Freshwater is defined as water with less than 0.5 parts per thousand dissolved salts. Freshwater bodies include lakes and ponds, rivers, some bodies of underground water and many kinds of man-made freshwater bodies, such as canals, ditches and reservoirs. The ultimate source of freshwater is the precipitation of atmosphere in the form of rain and snow.

Water salinity based on dissolved salts in parts per thousand (ppt)
Freshwater Brackish water Saline water Brine
< 0.5 0.5 - 35 35 - 50 > 50

Water distribution

Access to unpolluted freshwater is a critical issue for the survival of many species, including humans, who must drink freshwater in order to survive. Only three percent of the water on Earth is freshwater in nature, and about two-thirds of this is frozen in glaciers and polar ice caps. Most of the rest is underground and only 0.3 percent is surface water. Freshwater lakes, most notably Lake Baikal in Russia and the Great Lakes in North America, contain seven-eighths of this fresh surface water. Swamps have most of the balance with only a small amount in rivers, most notably the Amazon River. The atmosphere contains 0.04% water. In areas with no freshwater on the ground surface, freshwater derived from precipitation may, because of its lower density, overlie saline ground water in lenses or layers.

Aquatic organisms

Freshwater creates a hypotonic environment for aquatic organisms. This is problematic for some organisms, whose cell membranes will burst if excess water is not excreted. Some protists accomplish this using contractile vacuoles, while freshwater fish excrete excess water via the kidney. Although most aquatic organisms have a limited ability to regulate their osmotic balance and therefore can only live within a narrow range of salinity, diadromous fish have the ability to migrate between freshwater and saline water bodies. During these migrations they undergo changes to adapt to the surroundings of the changed salinities; these processes are hormonally controlled. The eel (Anguilla anguilla) uses the hormone prolactin, while in salmon (Salmo salar) the hormone cortisol plays a key role during this process.

Nature Activity VS Human Activity

Freshwater is a highly valuable natural resource that has a variety of use in both human and nature activity. Freshwater is an important natural resource that allow local ecosystem of plantations of species to survive. Flows of freshwater also bring soils and nutrients that are necessary in the growth and increase of local plantation which forms food chain that ensure the food supply of local species. However, the overuse of water in human activity such as irrigation, production of products in industries and drinking water had cause a huge damage in freshwater and nature ecosystem. “Changes in the contamination of freshwater results in massive diebacks of living organism, because of either too much or too little freshwater was contained in water source” (Jill S. et al., 2002, P. 1247-1260). The overuse of freshwater lowered the quantities of freshwater available in the freshwater ecosystem which caused the crush of balance between human society and nature. As a result, large amount of species and plantations became endangered and even extinct from the world and the local environment due to the large scale of change. Usage of freshwater must be controlled before it causes damage in environment and human society.

Agriculture- Change of Landscape

Changing landscape for the use of agriculture creates a great effect on flow of freshwater and surrounding. Reshaping a large scale of landscape in creating lands that are suitable for agriculture changed the flow and sustainability of freshwater which result in effecting the sustainability of the local ecosystem. Changes in landscape through the remove of trees and soils changed the local environments flow of freshwater and also effect the cycle of freshwater. As a result more freshwater are consumed and stored in soil which benefits agriculture. However, since “agriculture was the human activity that consumes the most freshwater” (Gordon L., D. M. ,2003, P.1973-1984), freshwater would be used up completely which result in scarcity and destroy of local ecosystem. Similar to events happening in Australia where too much land and freshwater flow are restructured for the use of agriculture, which ends up causing “33% of lands area at risk of salinization and scarcity” (Gordon L., D. M. ,2003, P.1973-1984). Redesigning lands for the maximum use of agriculture will certainly bring a great damage to the environment and reduces the available freshwater supply since freshwater is a limiting natural resource.

Limiting Resource

Freshwater is a renewable but limiting natural resource. As contamination of freshwater in freshwater ecosystem decrease, nature restored it contamination of water through precipitation in the process of water cycle. Freshwater can only be renewed through the process of water cycle, where water from seas, lakes, rivers, and dams being evaporates and formed into clouds then returning to water sources as precipitation. However, more freshwater are consumed through human activities before nature are able to restore them through water cycle. This causes more and more freshwater being consumed before they are restored. As the result the quantity of freshwater available in the lakes, rivers, dams and underground waters are lowered causing serious damage in surrounding environment. Freshwater would certainly be used up if no action were applied to restore and maintain freshwater.

Freshwater Management Program

Development of freshwater managing program helps to maintain and restore world’s freshwater and freshwater ecosystem. As the world population increases more and more freshwater are needed to satisfied world demand of freshwater which reduce the quantity of available freshwater and also caused a great damage in nature environment. In order to restore the freshwater and freshwater ecosystem six steps are taken to develop the freshwater management program. In the first step of developing freshwater management program the flow of freshwater and the maximum amount of freshwater needed for the environment was estimated. This ensure the nature environment, local plantation and species received enough freshwater that are needed for survival. In the second step of the process influence of human activity and the amount of freshwater human needs was estimated to ensure the supply of freshwater for both drinking and human activities. In the third step the location of the place that the program is going to take place is identify and compared to the previous estimate. By this way incorrect estimate can be corrected to ensure the environment receive the maximum amount of freshwater that it needs. In the forth step a detail outline of the plan that matches the collected data, estimation, and government’s requirement were developed. In the fifth step the program are tested in a simple freshwater experiment and results are observed to improve and also correct any mistake that occur in the plan. In the last step the planed was retested and more research was made to improve and make sure the plane function would function correctly. After that the environment’s adoptability to the program are examined to ensure the plan contribute no further damage to the environment. Freshwater management program would certainly contribute a great effort in restoring and maintaining the world’s available freshwater and freshwater ecology.

Freshwater management program must be created through worldwide vision. In order to create a successful water management program, the program manager must never create the program through an economic view. Creating a water management program through economic point of view brought only a short term success in restoring freshwater and freshwater ecosystem. However, by having a worldwide view and consider the flow of “freshwater as bloodstream of the biosphere’s capacity and breath of the Earth” (Carl F., 2003, P.2027-2036), an efficient and effective water management program can be created. Have a worldwide view and consider flows of freshwater as breath of the atmosphere and bloodstream of earth allows the program manager to find out what the environment really need in restoring its freshwater and ecosystem. The worldwide view also allowed the program manager to understand the difference between each freshwater ecosystem and helps to develop plans that will work efficiently in the environment. Worldwide view is the key to develop a successful water management program.

Creating an effective water management program benefit both presents and future’s human society and nature environment. As the global population increase the limiting water resource will become even more limiting. The greenhouse gases produced by human will also contribute a great effect to global warming which will cause the ice and glacier in North Pole and South Pole to melt. The melt of ice will result in increase of global sea level which might cover the land and mixed with freshwater. Developing an effective water management program helps not just in restoring the freshwater and freshwater ecosystem but also helps in reducing greenhouse gasses through the increase of plantation. Water management program will certainly contribute a lot in restoring and maintaining global freshwater supply and nature environment.

See also


  • Jill S. Baron, N. LeRoy Poff, Paul L. Angermeier, Clifford N. Dahm, Peter H. Gleick, Nelson G. Hairston, Jr., Robert B. Jackson, Carol A. Johnston, Brian D. Richter, Alan D. Steinman (2002). Meeting ecological and societal needs for freshwater. Ecological Applications , 12 (5), 1247-1260.
  • Carl, F. (2003). Freshwater for resilience: A Shift in thinking. Philosophical Transactions: Biological Sciences, 358 (1440), 2027-2036.
  • Brian D. Richter, R. M. (2003). Ecologically sustainable water management: managing river flows for ecological integrity. Ecological Applications , 13 (1), 206-224.
  • Gordon L., D. M. (2003). Land cover change and water vapour flows: learning from Australia. Philosophical Transactions: Biological Sciences , 358 (1440), 1973-1984.
  • Robert B. Jackson, S. R. (2001). Water in a changing world. Ecological Applications , 11 (4), 1027-1045.

Further reading

External links

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