What does “fresh water” mean

Water is an essential part of our planet, a crucial element for the survival of many lifeforms. Whilst the majority of water on the Earth is saltwater, only a tiny fraction of it is defined as fresh water. In this article, we will explore in detail what we mean by “fresh water”, looking at its sources, the ecological role it plays, and the great challenges we face to ensure its sustainability.

1 - Definition and properties of fresh water

Fresh water, with its unique composition which is fundamental for life, is one of the most precious resources on our planet. In general terms, fresh water is defined as any inland body of water which stems directly from glacier melt or rainwater.  In contrast to saltwater, fresh water is defined by its low concentration of dissolved salts, less than 1,000 mg/L, which makes it ideal for human consumption and for certain ecosystems which depend on it.

The main sources of fresh water are found in nature and include bodies of surface water such as rivers, lakes, streams, and even glaciers which, by melting, slowly feed these waterways. 

Groundwater, which collects in underground aquifers and reservoirs, are vital: often invisible, they are a vital resource which provides us with access to clean water via wells and springs. At any time of the year, in any location, fresh water sources support the water cycle and are at the heart of human communities and societies found in nature.

It is worth remembering that only 3% of the total water found on the planet is fresh, and that the vast majority of that is solid in the form of glaciers (more than two thirds).

2 - The ecological importance and role of fresh water

It is no exaggeration to say that fresh water is the engine that powers life on Earth. Every drop of fresh water supports a delicate balance of biodiversity, from tiny organisms to huge, complex ecosystems. From rivers carving their way through mountains to deep, calm lakes, these bodies of water are home to a diverse variety of plants and animals that are highly dependent on fresh water. If these water courses were to become salty, the ecosystems would suffer serious consequences, with many species of animals and plants dying out in a very short period of time.

For example, wetlands are ecosystems of extraordinary beauty and vitality, where flora and fauna prosper thanks to the purity and abundance of fresh water. Moreover, it is very important to remember that fresh water ecosystems do not just sustain biodiversity, they also perform a crucial role in purifying that water. The natural filtration processes that occur in lakes and rivers help to remove pollutants, making the water safer, even for human consumption. These environments act as our planet’s “lungs”, not only providing a habitat but purifying and recycling the water resources that we all depend on and, as we will see in the next paragraph, which are also crucial for agriculture.

3 - Fresh water and human life

Fresh water is not just a biological requirement, it is also a resource that humanity has treasured for centuries. From irrigating crops to powering industry, fresh water is an integral part of our daily lives. 

Agriculture is the main consumer of fresh water, which is vital for crops such as rice, wheat, fruit, and vegetables. Without this vital resource, arable and animal farmers would feel the effects as they depend on fresh water to irrigate their fields and feed their animals. Fresh water is therefore crucial for ensuring the sustainability of food production. Excessive use of water, such as for intensive crop and animal farming, can compromise water reserves, threatening its ability to meet future needs.

And that is not all: fresh water is the basis for so much in our everyday lives, from preparing food to cleaning our homes. The quality of water is crucial not just for our health but also for our general well-being. This is why managing water resources and protecting fresh water sources is not just a priority for scientists, it has to become something to which we all contribute.

4 - Threats to fresh water sustainability

Despite its apparent abundance, fresh water is a fragile resource which is under pressure. Its sustainability faces multiple urgent threats. Pollution is a big challenge: every year, tons and tons of chemicals, plastics (which break down into microplastics) and other rubbish end up in our waterways, comprising the quality of the fresh water and jeopardising the health of both people and ecosystems.

In addition, climate change is accelerating the depletion of fresh water resources. Changes to the rain cycle, the rapid melting of glaciers, and the increase in global temperatures are all contributing to making certain regions much dryer and unable to meet the water needs of the population. In addition to this, there is the salination of aquifers in coastal areas, where rising sea levels cause saltwater contamination of fresh water reserves. Desertification, drought, a reduction in water reserves, and salination all pose major challenges that require immediate action.

5 - Solutions and conservation methods

Faced with these challenges, conservation of fresh water is no longer an option: it is an urgent requirement. Fortunately, there are many innovative, practical, and practical sustainable solutions that we can implement. First of all, responsible use of water is a top priority: reducing waste, implementing water recycling technologies and protecting fresh water sources are all crucial steps towards sustainable water resource management.

In agriculture, advanced technologies such as drip irrigation and cultivation in low-water-consumption greenhouses are making a big difference, helping to reduce the amount of water wasted in farming. Domestically, using systems to collect rainwater, combined with informed choices, can help to reduce a family’s water footprint.
In addition, protection of wetlands, the creation of protected areas around rivers and lakes, and continuous monitoring of water quality are all essential steps that will help to ensure that future generations will be able to enjoy this priceless resource.

6 - Conclusions

Fresh water is the Earth’s lifeblood, essential for the survival of all living beings. It is our duty to protect it and manage it carefully, understanding that every drop counts. Every action we take, even tiny ones, can contribute to preserving this irreplaceable resource for future generations. It is a huge challenge, but together we can create a future where fresh water will continue to sustain life and make our planet thrive.