Have you ever thought about how much water has been used to make your shoes or the clothes you are wearing? How much to produce the food you eat? How much of this water have been polluted in these processes? You should know about the “water footprint”.
We live in a world where water wars are a theme of concern for organizations like United Nations and the World Trade Organization. Currently, one third of the world population live in countries where there isn’t enough water or its quality has been compromised. This figure is expected to rise to two-thirds in 2025. You might wonder why; there is a lot of water in the world! It is true, but actually only a very little part of this water is available for us to use. Most of it is salt water; only 2.5% is freshwater. Moreover, this freshwater is locked in glaciers (68.9%), in the ground (30.8%) and only a 0.3% is available in lakes and rivers (FAO WATER) From this small portion of water available, around 70% is used for agriculture. We must learn to use this vital resource sustainably and to reduce negative impacts on the environment.
The water footprint is a measure of humanity’s appropriation of freshwater in terms of how much has been consumed and/or polluted. It can be estimated for a single person or for a community like a family, a town or a country.
Your water footprint is the amount of water you use in your daily life. It includes the water you use directly (e.g., from a tap), but also the water it took to produce the food you eat, the products you buy, the energy you consume. It even takes into account the water you save when you recycle. You may not drink, feel or see this virtual water, but it actually makes up the majority of your water footprint. You can calculate it with this tool from National Geographic.
The water footprint consists of three components: the blue, green and grey water footprint.
- The blue water footprint is the volume of fresh water evaporated from the global blue water resources (surface water and ground water) to produce the goods and services consumed by an individual or community.
- The green water footprint is the volume of water evaporated from the global green water resources
(rainwater stored in the soil as soil moisture).
- The grey water footprint is the volume of polluted water associated with the production of goods and services. Grey water can also be estimated as the (much larger) volume of fresh water that is required to dilute the polluted water until its quality is within agreed water quality standards.
So, how hydroponics help lowering the water footprint?
In traditional agriculture, a lot of the water is wasted and only a small portion is actually used by the plants. Most of it is evaporated from the soil and lost to leaching. A big problem with this leached water is that it is full of fertilizers, and it will end up at rivers and lakes. Why is that a problem? Because then you get eutrophication. This fancy word is a form of pollution: well feed algae bloom explosively. Algae remains accumulate and decompose taking up all the oxygen thus causing the death of fish and most other living things.
Everything changes when we talk about hydroponics:
- Little loss to evaporation from substrate and reservoirs.
- You can know how much water your crop needs and use exactly that.
- No loss to leaching.
- In recirculating systems the emission to the environment is minimum which means no eutrophication.
- Hydroponic systems require fewer pesticides thus producing less grey water.
- Local produce needs less transport, reducing the energy that food normally takes to get to our kitchen.
You see why we are such fans of hydroponics. Our mission is to enable anyone, anywhere to grow a hydroponic crop. It could help us saving our world, no less.