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The Water Cycle: From Earth's Freshwater Supply to the Elements We Use Everyday


The Water Cycle: From Earth's Freshwater Supply to the Elements We Use Everyday

The water cycle is one of the many natural processes that take place on Earth, from which we get our fresh water supply and ultimately all the elements we use in our daily life. But how does it work? And why do we care? Read on to learn more about the water cycle, what it means to us, and how you can get involved in protecting it!

The Water Cycle
Water Cycle

An Introduction

The water cycle is a series of natural processes that take place on Earth, from which we get our fresh water supply and ultimately all the elements we use in our daily life. The water cycle begins with evaporation, where water is turned into vapor and rises into the atmosphere. 

Then, condensation occurs, where the vapor cools and forms clouds. Next, precipitation falls from the clouds in the form of rain, sleet, or snow. Some evaporate once again and go back into the process. In addition, groundwater provides another source of drinking water for people around the world as it slowly seeps down through soil and rock until it reaches an aquifer at great depths below ground level.

Precipitation - snow, rain, hail...

Precipitation is one of the main ways water enters the water cycle. When precipitation falls from the atmosphere to the ground, it can either seep into the ground or run off the surface. If it seeps into the ground, it becomes groundwater. If it runs off, it can either become surface water or evaporate back into the atmosphere. 

Surface water can flow downhill and collect in streams, lakes, and oceans. Ocean water also enters the water cycle when it makes contact with the atmosphere and starts to evaporate again (this process is called evaporation). The sun's heat causes moisture in the air near the ocean to change into a vapor form (known as condensation).

Surface Runoff

When it rains, water runs off of the land and into rivers, lakes, and oceans. This is called surface runoff. Most of the water that we use for drinking, cooking, and bathing comes from surface runoff. However, most of this water is not drinkable because it contains contaminants such as chemicals and bacteria. 

To remove these contaminants, we need to clean the surface runoff before using it for anything else. The process of cleaning the surface runoff involves two steps: filtering it through sand or gravel (to get rid of some pollutants) and then boiling it (to get rid of bacteria).

Subsurface Runoff

When precipitation falls on land, it can either seep into the ground or run off the surface. This subsurface runoff eventually makes its way into rivers and streams, which is where we get our fresh water supply. The water cycle is a never-ending process, and we rely on it for our survival. Every day we use the elements from this process in some form or another, whether drinking, washing with soap and water, cooking food with potable water, or using clean water for other purposes. There are many ways that humans interact with this natural phenomenon.

Deep Groundwater Recharge

The water cycle begins with precipitation, which can be in the form of rain, snow, or sleet. This water then seeps into the ground, where it is stored in aquifers. Aquifers are underground layers of rock that hold water. When we use groundwater for things like drinking and irrigation, we are recharging the aquifer. As these underground sources of fresh water get depleted, we need to find new ways to replenish them. 

One way this can happen is by building ponds, reservoirs, and wetlands on top of an aquifer to keep water from evaporating. Another way would be by capturing storm runoff from rooftops and roadways through permeable pavements or green roofs. In areas where aquifers are running low, there has been a lot of research done on desalination—a process whereby salt and other minerals are removed from seawater to produce drinkable water. Desalination plants remove salt and other minerals from seawater using a process called reverse osmosis.

Groundwater Flow

Groundwater is water that soaks into the ground and is stored in aquifers, which are porous rock formations underground. When it rains, some of the water seeps down through the soil and recharge the aquifers. This process is called groundwater flow. The water in aquifers is under pressure, so it will eventually rise back up to the surface through springs or wells. 

As these freshwater supplies emerge from the ground, they can be used for drinking, irrigation, and industry. These freshwater sources also replenish streams and rivers during a drought when there isn't enough rain to keep them full. As the water level rises in a river, small lakes may form upstream. Eventually, all this excess water flows downstream where it empties into larger bodies of water like oceans and lakes. Rivers carry sand, silt, and other materials along with them as they flow downstream. 

Large amounts of silt might build up at the mouth of a river as it enters an ocean or lake if there isn't enough sediment being carried downstream by the river because of erosion upstream.


The water cycle begins with precipitation, which can be in the form of rain, snow, or hail. This water then flows into rivers and streams, which is called surface runoff. Some of this water seeps into the ground, where it becomes groundwater. Groundwater eventually flows back into rivers and streams, completing the water cycle. In the process, we gain access to freshwater supplies that are essential for our survival on Earth. 

It also provides us with all the elements we use daily; such as oxygen, hydrogen, nitrogen, carbon dioxide, sulfur dioxide, and more. If a human needs these substances for their body to function properly, they will either consume them (like consuming air) or find an outside source (like drinking water).


Did you know that the water you drink today might have been part of a river flow long ago? The water cycle is a never-ending process of evaporation and precipitation that starts with freshwater bodies like rivers. As water evaporates into the atmosphere, it eventually falls back down to Earth in the form of rain or snow. This moisture then seeps into the ground, where it becomes part of our groundwater supply. Finally, the water is drawn back up into the atmosphere and the cycle begins anew. 

When we draw on this groundwater for drinking water, we're drawing from this ever-flowing wellspring of freshness. It may sound strange to think about your drinking water as coming from hundreds or even thousands of miles away, but what goes around comes around!

Estuaries & Oceans

Estuaries are where freshwater from rivers and streams meets saltwater from the ocean. The water in estuaries is usually brackish, meaning it is a mix of fresh and salt water. Estuaries are important because they are transition zones between land and sea, and they provide habitat for a variety of plants and animals. They also act as nurseries for young fish and crustaceans, which later migrate to deeper waters or move upstream into rivers. 

When salt water moves inland through an estuary during high tide, it can contaminate the groundwater if there is no way for it to flow back out through coastal wetlands. Groundwater can become salty when this happens, and it cannot be used by humans or crops. Rivers & Streams: River flows are affected by rainfall levels; when the rain season is intense, the flow of rivers increases dramatically while springs dry up. Streams get their water primarily from precipitation that falls directly on them. 

Rivers eventually reach a body of water like an ocean or lake, where some of its water evaporates back into the atmosphere (evaporation).


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