A girl drinking clear water from a tap
9 min read

How can we use groundwater more sustainably?


We need to rethink the use of our most important resource

Our way of life is largely based on a resource whose presence we have always taken for granted: groundwater. If we syphon it off faster than it can renew itself, this will have serious consequences for our society as a whole. We have to learn to use it more efficiently and develop alternative sources of water – and that's where solutions from KSB come in.

Infographic on the distribution of the world's water resources

Groundwater is a resource with limitations

Water covers 71 percent of our planet. So why are we so dependent on groundwater? The reason is that 97 percent of the water on earth is salt water and groundwater accounts for most of the fresh water we can use. That's why, for example, 65 percent of drinking water in the European Union comes from the ground, compared with 50 percent in the United States. It is crucial not only for clean water supply, but also for food production, stability of ecosystems, socio-economic development and the resilience of communities to climate change. But humanity's water consumption is rising. At the same time, climate change is bringing more droughts and heavy rains, causing great volumes of water to simply run off instead of seeping into the ground. So we need to think about how we can use this crucial resource more sustainably.

What are the consequences of falling groundwater levels?

Groundwater is found in aquifers, which are layers of sediment or porous rock that are saturated with water. Most aquifers can be refilled by rainwater percolating down from above. But if we take out more water than flows in, this can have numerous consequences.
Soils become drier. Native trees no longer reach the water with their roots and wither away. Invasive plants that are better adapted to drought start to spread. Springs dry up – and with them, ecosystems such as streams, lakes and wetlands disappear. The level of rivers and lakes falls. The ground can subside, causing damage to buildings. In the remaining groundwater, the concentration of pollutants such as nitrates increases.

To prevent this, we need to withdraw water more slowly than the aquifers can replenish themselves. This calls for data as well as political regulations. One prerequisite is that we no longer think of groundwater as the property of the owner of the land on which it is extracted, but as a shared commodity that must be protected collectively – like the air we breathe or the water of the oceans.

One challenging factor here is that aquifers cross national boundaries. International agreements on the use of water resources are therefore an important component of the United Nations Sustainable Development Goal 6.
However, both collecting data and controlling groundwater extraction are often difficult political processes. According to the United Nations, there are only 22 countries in the world that have entered into cross-border agreements with their neighbours to use all of their shared aquifers, lakes and rivers. And 129 countries are not yet on track to have sustainably managed water resources by 2030.

What is the state of our own aquifers?

How long will the water beneath our feet last? There are no easy answers to this question. With aquifers, we cannot simply measure the water level as we can with a river or lake. To understand how much water is underground, we need to drill numerous boreholes and measure where the groundwater begins and how deep it goes. Furthermore, groundwater does not have a uniform water level like a lake. It is very heterogeneous and can be distributed over a wide variety of layers. The situation at the location of a borehole can look quite different from that a few hundred metres further on. So to understand an aquifer, we need large numbers of boreholes spread over large areas. This is complicated by the fact that aquifers often extend across national boundaries.

Map showing the burden on the largest aquifers in the world

Groundwater storage trends for the 37 largest aquifers on earth

A look at the changes in all aquifers worldwide was only made possible for the first time by NASA's Gravity Recovery and Climate Experiment (GRACE). Between 2003 and 2013, two satellites measured changes in the Earth's gravitational field. This allowed them to draw conclusions about changes in the amount of water stored in a region. The results were sobering: 21 of the 37 largest aquifers on earth are shrinking from year to year. Of these, 13 could replenish themselves only slightly, if at all.

Infographic of the share of agriculture in groundwater abstraction

Irrigation plays the key role

So how can we manage our groundwater more sustainably? Agriculture plays the decisive role here. This is because 70 percent of the world's groundwater is used to irrigate fields to produce food. And in the future we will have to produce much more food. This is because, according to United Nations estimates, the global population will rise from 7.8 billion today to 9.7 billion by 2050. Not only will the number of people change, but so will their eating habits: as they become more affluent, they will want to consume more meat and dairy products. And this, in turn, requires new acreage to produce feed for chickens, cattle and pigs. The Food and Agriculture Organization (FAO) of the United Nations therefore expects that we will have to produce 60 percent more food by 2050. So if we want to use our groundwater more sustainably, we must above all make the use of water in agriculture more efficient and productive.

Smart irrigation saves groundwater

To get an idea of how more food can be produced with less water, it's worth taking a look at Israel. Although the country has a very dry climate and more than half of its land is desert, it not only produces 95 percent of its own food, but is also a major exporter of agricultural products such as avocados and dates.

This success is based in part on drip irrigation, in which Israeli companies are world leaders. Instead of spraying fields with water and fertilizer, small amounts of both are passed through a system of hoses and dripped directly onto the roots of the plants. The advantage is that less water is lost through evaporation and seepage and fertilizer reaches the roots of the plants directly. Not only is less water needed for irrigation, but there is also less groundwater pollution caused by seeping fertilizer.

An apple orchard with drip irrigation

Treated wastewater becomes an alternative

Without question, drip irrigation is the most efficient method of irrigation. If implemented in conjunction with state control of the extraction of water from wells, it can contribute significantly to groundwater conservation. In doing so, it not only saves water, but also leads to better plant growth and larger harvests. This type of irrigation is particularly well suited for high-value agricultural products such as fruits or vegetables grown in warm regions with scarce supplies of water. Another advantage is that irrigation systems can use treated waste water which has not been fully purified to drinking water standards. Legal regulations generally do not allow such water to be sprayed in the air. Here, too, Israel is a world leader: it recycles 90 percent of its waste water and uses about half of the water thus obtained for agriculture.

Sustainability needs efficient technology

Producing more food with less water will only be possible through efficient technology. Economical irrigation systems such as drip irrigation will only catch on if their total cost of ownership is attractive to farmers. That is why we incorporate decades of know-how into the development of our pumps. One example is our UPA S submersible borehole pump, which is often used as a well pump in irrigation. Its wear-resistant design with metal casing wear rings and bearings made of silicon carbide has been devised to keep energy consumption low over the long term, even if large amounts of sand are contained in the water. Combined with a UMA-S synchronous motor and a variable speed system, it achieves further significant reductions in energy costs. In addition, it is completely maintenance-free, has hardly any wear and offers maximum service life. This not only saves our customers energy costs, but also significantly reduces their CO₂ emissions. This is our contribution to sustainability through technical progress.

UPA S

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