What are the Earth's Sources of Water?

Rainwater is an example of a water source.
Rainwater is an example of a water source.

Water is one of the most important commodities on earth and it is essential to human life. It is used in diverse areas such as farming, cooking, cleaning, construction, and even for recreational purposes. There are numerous sources of water ranging from underground sources to surface sources. Oceans, ponds, lakes, rivers, springs, aquifers, and streams are some of the main water sources in the world. All these sources are essential for people’s well-being.


Oceans are the largest sources of water on the planet. There are five oceans in the entire world. They contain approximately 97% of all the earth’s water. Despite the massive quantities of the essential commodity, ocean water is not suitable for human consumption in its raw form. It contains high salt levels and other impurities that make it unsuitable for household use. However, countries situated in dry regions such as Saudi Arabia, the United Arab Emirates, China, Oman, and Australia use a technique known as desalination to purify ocean water. Desalination involves the striping of salts and other components found in ocean water. The process is not widely used due to huge costs and high energy levels involved. A popular mode of purifying salt water from the ocean is reverse-osmosis where water passes through microscopic pores and salts among other impurities are filtered.


Lakes are an important source of livelihood for many people around the world. Scientists estimate that there are 117 million lakes throughout the world. Lakes are classified into two categories: salt-water lakes and freshwater lakes. Water found in lakes is put into different uses by the communities that live around the natural resource. The main use of lake water is in the fishing industry. Most people who live near lakes practice fishing. Farming communities also use lake water to irrigate their farms and boost their agricultural output. Additionally, water in lakes is used as a mode of transport from one point to another whereby people use boats or advanced equipment to travel across the water body.


Rivers are natural paths through which water flows toward another river or a larger water body. There are countless rivers flowing in different directions throughout the world. Rivers are important sources of food, mode of travel, hydro-power sources, and popular tourist attractions. The world’s most prominent river, Amazon River flows through Peru, Columbia, and Brazil and provides water for farming, hydro-power generation, marine life industry, transportation, and acts as a tourist site. The Amazon River is estimated to carry 20% of all the fresh water found on earth.

Glaciers and Icecaps

Glaciers and ice caps are natural sources of fresh water. Glaciers are formed when large pieces of ice accumulate over several years. Most glaciers and ice caps are found in extremely elevated regions and areas close to the North and South Pole. They are critical naturally occurring resources that help regulate the earth’s temperatures and climatic conditions. Glaciers are the largest sources of fresh water, and they store an estimated 75% of the earth’s fresh water. Even with the large quantities of useful fresh water contained in glaciers and ice caps, they are rarely used as water sources due to the high amount of funds needed to melt the thick ice and transport the water to residential areas. The enormous natural bodies melt slowly and flow into nearby rivers where people use the water.


Aquifers are water sources found below the surface of the earth. They are underground rock formations that contain water. An estimated 30% of the world’s liquid water is found below ground. Water in underground aquifers may come to the surface through natural springs. In some cases, the water is pumped to the surface through specialized equipment. Aquifers are important water sources, especially in arid areas. The cost of extracting the water from aquifers is often within reach. The natural resources provide water for irrigation, industrial use, and household needs. Some aquifers have highly saline water that needs to be desalinated before being put into use.


Ponds are shallow water sources usually smaller than a lake. Ponds are part of the many surface water sources. Some ponds occur naturally while others are human-made. Ponds may contain aquatic plants and animals. Water found in ponds is often used to support agriculture, fishing industry, landscaping ventures, and in rehabilitation of damaged land. Some ponds are used as habitats for rare and endangered species. As a result, they improve the biodiversity in areas where they are found.


Springs are natural freshwater sources found on the earth’s surface. They get their water from underground streams or aquifers. Some springs may produce hot water, like the breathtaking geysers, while others produce cold water. Spring water is often used in commercial production of drinking water. Additionally, hot springs are popular tourist attractions, religious sites, and recreational centers.


Rainwater is the cheapest naturally occurring water source. It is a seasonal source of water. The rainwater is collected in water tanks and dams in the rainy season for use in the dry season. Most people in the developing world rely on rainwater as their only source of water. Rainwater is used for household needs, farming, replenishing ponds, and hydro-power generation.


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