How can we save water?
The depletion and pollution of water resources has been a problem for years now, and we have not found a proper answer to solve this global challenge yet.
The following advice can help us save water in our daily life:
- When you wash your hands, turn off the tap while you soap up, and when you dry your hands.
- Turn off the tap while you brush your teeth.
- Place two half a litre bottles filled with sand in the toilet tank, so less water is needed to fill the tank and therefore less water is used to flush it.
- When you shower, turn the water off while applying shower gel and shampoo.
- Replace gaskets to fix any leaking taps.
- When washing clothes by hand, only turn on the tap while you soak clothes and to rinse them at the end. Wash only once.
- When boiling water, do not boil longer than 10 minutes.
- Wash all vegetables at once in a basin. You can cook the vegetables in a small amount of water, and reuse it to prepare soup.
Technology can also be used to ensure efficient water use. Some examples follow.
- Irrigation technologies: there are several techniques to save water in irrigation: (1) harvest rainwater using small pits (dug by hand) to collect the water; (2) deficit irrigation, by limiting water applications during plant growth stages that are less sensitive to lack of moisture, thereby encouraging root growth and contributing to efficient water use; (3) supplemental irrigation, by applying runoff water collected in ponds, tanks or small impoundments, during critical plant growth stages; (4) irrigation systems and infrastructure can offer many other services, such as water supply for domestic use, livestock production and electric power generation.
- Desalination technologies: they allow saving water and water use efficiency, tapping previously unused sources such as seawater, as well as ensuring the availability and quality of the water supply. Some of the most commonly used technologies worldwide are distillation and reverse osmosis.
- Water reuse: there are many techniques to save wastewater by industry, based on recycling water for other uses such as irrigation or washing down surfaces.
- Technologies to address water leaks in cities: for example, acoustic technology to detect water leaks in Singapore or using robots to patrol the urban pipeline network in Los Angeles. Only in the United States, old and leaky pipelines lead to the loss of almost 8 trillion litres of water per year.
International water saving measures are also urgently needed. The late Arjen Y. Hoekstra, Professor of Water Management at the University of Twente, who came up with the "water footprint" concept, suggested the following measures:
- Establish water footprint limits for all water withdrawal catchments, necessary to set a water consumption threshold. Moreover, it is important to secure a minimum volume of water for the maintenance of biodiversity and ecosystems, and for the people that live downstream.
- Establish water footprint parameters for all uses that require a large amount of water, such as food, drink, clothing, flowers and bioenergy, promoting the best available technologies and practices.
- Promote fair water use by communities, given that the volume of water per person in the world is limited, thus making necessary policy action globally. Only in the United States and Western Europe, the water footprint of consumers is almost twice as much as the global average.
Saving water is important because water scarcity is considered a global systemic risk. According to a study by Mesfin M. Mekonnen and Arjen Y. Hoekstra, two thirds of the world's population live under conditions of severe water scarcity at least one month of the year.
In some cases, surface water bodies as important as the Aral Sea in Central Asia and Lake Urmia in Iran have disappeared as a result of upstream water use. Furthermore, groundwater reserves are being depleted at an alarming pace in all continents. In some cases, the rate of withdrawal is up to 10 and 50 fold the rate of natural recharge.
Another problem that relates to water scarcity is widespread pollution. Fertilisers and pesticides used in agriculture end up in rivers, violating water quality regulations; in many cases, the authorities do not take appropriate measures.