Running the tap to drink, or to have a shower, or to clean our dishes is one the most common actions that we do every day. Clean and fresh water flows to our house. It is something normal, or actually it is not? Can we really afford to take it for granted? Well, answer yourself after reading the information below.

What determines how much water we consume?

Today, the global withdrawal of water (meaning freshwater taken from ground or surface water sources such as rivers or lakes) for agriculture, industrial and domestic uses is more than 4 trillion m3 per year.

The consumption of water has been increasing rapidly since 1900 till today. The growing world population, agriculture and industrial consumption patterns, and the structure of economies are the main factors.

The global population in 1900 was 1.6 billion, while as of December 2019 is almost 8 billion. In addition to this, the consumption of water per capita for personal use has also increased substantially in the last 50 years, mainly in developed countries.

Another very important factor is the gross domestic product (GDP) per capita. At lower incomes, agriculture’s share of total water consumption is higher. It is usually connected with very inefficient irrigation methods. Something similar happens when it comes to industrial water usage. At higher GDP, generally the industrial sector is more modern, using better and more efficient technologies.

Additionally, the lower the GDP, the higher the rural share of total population.

Water for Agriculture

Water is the key for agriculture. Paradoxically data on agricultural water consumption is usually not reported properly. We can estimate that we use for agriculture around 70% total water use. However, this ratio fluctuates significantly depending on the income level of the region, from 90% in poor regions to 40% in the richest areas.

Irrigation is the main factor which impacts in water use amount for agriculture.

Water for Industrial Use

There is a wide range of industrial processes which use water. USA is at the top of this ranking, using twice the amount of industrial water compared to China as the second in the list

Industrial water reaches 19% of total water withdrawals. In this case, the fluctuation is opposite to agriculture, being rich regions the main users. Poor regions only use 2% of total water use for industrial purposes.

Water for Public Services

This is probably the most “popular” water, as we all use it for drinking, cooking, washing and cleaning. Due to this reason, the consumption per capita is a very relevant ratio. We can see that USA uses more water for domestic use than India, even though the population is much lower. This is because a much higher demand of water per capita.

Around 11% of total water use is for domestic purposes.

Water use and stress

In order to keep water resources in sustainable levels, withdrawals should be below rates of water renewals.

These indicators are usually measured per capita. So if we consider the renewable resources of water staying at the same level but the population grows, per capita indicator drops. This is the case of many countries in the world.

Depending on the annual amount of water consumption compared to renewable water resources, the World Resources Institute (WRI) defines the water stress levels as follows:

  • <10% – low stress
  • 10-20% – low-to-medium stress
  • 20-40% – medium-to-high stress
  • 40-80% – high stress
  • 80-100% – extremely high stress
  • >100% – water scarcity

How many renewable freshwater resources do we have?

Renewable internal freshwater resources mean the quantity of internal water from inflowing river basins and recharging groundwater aquifers, and reach 42.8 trillion m3.

Water pollution

Apart of the increase of water consumption ratios, another major problem is the constant deterioration of water quality, in other words water pollution.

Some people say that pollution is the price that we have to pay for progress. Well, I could not disagree more. Actually, as long as we progress more, the awareness of the need to solve this problem is higher and higher. Modern technologies of production tend to minimize environmental impact.

Just to make long story short, we can say that water pollution takes place when external elements are introduced in the water in such amount that they produce problems for living species.

Even though nature is very strong and self-healing, it is our responsibility to control and minimize the impact of human activity. Oceans, rivers and lakes are able to heal themselves till a certain extent when the amount of pollutants is low, and they can be dispersed in big quantities of water. The problem appears when small amounts are coming on top of another small amount, and this one on top of another one, and so on. Then it turns out that the amount is not small anymore. Obviously, a big introduction of pollutants in one shot is always a disaster.

Water and health

The quality of the available water is a fundamental aspect not only for the health of human beings, but also for the whole nature. It doesn’t matter whether we use water for drinking, agriculture, industrial uses or recreational purposes, a poor quality or contaminated water is always a factor which brings health issues.

This can really be a big problem in the case of absent or not correctly managed water infrastructures in public health services.

According to World Health Organization, in 2017 more than 2 billion people, around 30% of world population didn’t use safely managed drinking-water services free from contamination. As a result, more than 800 000 people die every year due to unsafe drinking-water, sanitation, and hand hygiene.

Economic and social effects

But the effect of water pollution is not limited to health issues. Water pollution can have a devastating effect in local and global economies. It can slow down the industrial progress. It can cause social inequality. It can kill the agricultural sector with the risk of regional starvation.

The better the water quality, the more productive the society can be. Obviously, when the health issues related to poor quality water are close to zero, the medical costs linked to those kinds of diseases can be also close to zero.

If good quality water becomes accessible, mainly in poor areas where people have to make long journeys to collect water, a lot of time and effort could be saved. As a result, productivity in other fields could be radically increased.

This is one of the biggest challenges for the near future. A quick development of the water infrastructures in poor areas will boost not only the quality of life and well-being in those areas but also the global economy.

Causes of water pollution

The causes of water pollution are very different, and you would be surprised by some of them. As an example, think about the smoke from chimneys which flows to the atmosphere and gets to the oceans when it rains. You can think also about the chemicals and fertilizers used in agriculture, which could get to the underground water or to the rivers nearby. The same happens with the salt placed on roads during winter time.

Having the above in consideration, it is easy to understand that water pollution is a very difficult problem to solve. That’s why it requires the commitment of all of us.


As the world population is growing so fast, sewage wastes are becoming a big and serious problem. In developed countries the sewage pipes and flushes take dirty waters quickly and in a safe way from homes. This is not always the case in poor regions of the world.

But this is only a small part of the problem. After the wastes are out of your home they go to the sewage system. And here we have problems even in rich countries as USA or UK. In some cities of these countries huge amount of raw sewage is still pumped untreated directly to rivers and to the sea every day.

Sewage water shouldn’t be a problem itself, as it is supposed to be a natural element. But when it comes to practice (bad practice, unfortunately), sewage water contains a lot of chemical substances, plastics, papers, pharmaceutical drugs, and a long lists of things that they shouldn’t be there when we flush.


If you think about nutrients, you might not consider it as problem. The point is that sometimes the nature can’t deal with amounts of nutrients released to the sewage, underground waters or rivers. It can cause algae bloom, which is a massive growth of species like algae or plankton overwhelming big areas. This is a problem because it reduces the presence of oxygen in the water, killing many living species. This is known as dead zones, like the one in the Gulf of Mexico.

Waste water

Industrial waste water, together with sewage, causes around 50% of all ocean pollution. Even though this fact, there is not many data taken to show the scale of this problem.

Much of industrial waste water is pumped untreated into rivers and oceans in many parts of the world. In USA, more than $70 billion have been invested in water treatment plants during the last 40 years, reaching almost 90% of the population. Still, more than $270 billion are needed to improve the system.

We have to be aware that not only industries and factories cause this kind of pollution. Almost everyone pours contaminants to the toilet or pollutes water with detergents for washing machines and dishwashers. We use a lot of chemicals and pesticides in our gardens. This is known as nonpoint sources of pollution.

A very particular cause of waste water is highways. They are covered with all kind of chemicals additives and fluids from the cars, exhaust emissions, worn tires and so on. All this usually gets into drains when it rains, ending up in river and other water flows.

Chemical waste

Highly toxic chemical substances are a major problem. Heavy metals like cadmium, mercury and lead are commonly used in batteries and petrol. Circuit boards were made from polychlorinated biphenyls (PCB), which is a very toxic pollutant. Another highly toxic chemical called tributyltin (TBT) was used to paint boats as protection from ocean effects.

Those are examples of global pollution caused miles away from where they entered in the environment. Some countries are already taking care of this problem and the use of these substances is regulated or even banned.

Radioactive waste

Radioactive waste can be fatal at high concentration levels, while at lower levels can cause cancer. Unfortunately, in very developed countries like UK or France, there are still cases of radioactive waste water from nuclear power plants discharged into the sea. Waves and sea currents can transport this waste hundreds and thousands of miles away from the source point.

Oil pollution

We all have in our mind the horrible image of huge oil slicks killing thousands of birds and fishes. Tanker spills cause such a high concentration of oil in a much localized area that they kill almost everything in there. Well, being as horrible as it looks, this is not the main source of oil pollution in the oceans. Around 75% of oil pollution comes from regular shipping and oil poured down on land.


More than 8 million tons of plastic are littered in the sea every year! There is even a huge island of plastic garbage in the Pacific, known as the Great Pacific Garbage Patch. Believe it or not, it is three times the size of France.

Even though plastics are not as toxic as other chemical products, they represent a very dangerous menace to birds and fishes. Plastic is the most common material in our modern society. It is light and it floats, so it can be transported by sea currents and waves thousands of miles away. In addition, plastic is not biodegradable, meaning that it can survive in the ocean up to more than 500 years.

Alien species

Pollution is not only chemical, it can be also biological.

This problem takes part when animals or plants from a given region are introduced in a different ecosystem. In many of these cases, the new species being out of their original environment don’t have any natural predator, so they can multiply very rapidly and wildly, killing the local animals. Very well known cases are in the Great Lakes of the USA, Black Sea or Europe causing costs of several hundreds of millions per year.

Other forms of pollution

Sometimes industries can cause thermal pollution, raising the temperature of rivers. This reduces the quantity of oxygen in the water.

Disruption of sediments flows is another type of pollution. This can be caused by dams in rivers and harbor breakwaters. This affects to formation of beaches and can reduce drastically the amount of sediment flow to the sea from the rivers.

Excess of sediments can also be a problem. This is usually the case during construction works, as dust, soil and rocks can end up into rivers and water flows.

What can we do to avoid water pollution?

It is true that this is a very difficult problem to solve. Exactly because of that, our commitment has to be even stronger. It is not only a matter of public administrations or governments. We need to be accountable as individuals also.


It is not possible to solve a problem if we are not aware of it. We are in the era of social media, and it can be a great tool to make the whole world aware! Once the society demands solutions the whole system starts to work. It is not an overnight process, but the tendency is pointing the right direction.


Being the future, education on environmental issues is a must for our kids. As they grow and get involved in routine and productive activities, they will transform the old bad habits into good practices.

But not only kids need education. It turns out that most of the times it is easier to educate a small kid than an adult. Every adult has to get involved in this process, and it comes with the great responsibility of teaching kids by our actions and example.

Anyone can help by disposing chemicals and toxic products properly, and being responsible when flushing. You can also use phosphate-free detergents.


Water pollution is a global issue. As rivers usually cross different countries and oceans span whole continents, different standards in different countries are a major problem.

International law plays a key role here. As the awareness of global society grows, the governments will be forced to take actions and apply new international common laws to protect the environment and reduce water pollution.


As a general approach, prevention is cleaner and more environmental friendly than reparation. In this sense, the idea of the polluter pays principle is not only based on paying to clean up. It means that polluting will result more expensive than to invest in operational systems to avoid pollution. If industries are forced to reuse their waste water, they will find ways to regenerate it properly.


At this point I am sure that everybody agrees that water pollution is an essential subject for all of us. The global population is growing constantly and quickly, so the needs of clean water are growing also. It is urgent to develop good practices in water management. We have also to implement reasonable policies for agriculture and industrial uses. But the change has to start within ourselves. It all relies on our personal accountability. The governments will do their part if we do ours before.

We are not where we want to be, but we know the way to get there. Let’s lead this positive tendency!