Water in AgricultureHow Agriculture Pollutes Water and How Local Strategies Can Change ItJulian Häderli, Brandon Schwab Rodriguez, and Tolga Tomel

A well known fact are the amount of glaciers Switzerland has, meaning the enormous storage of fresh water kept in the ever decreasing ice vault. Different studies and future scenarios indicate that the glaciers will lose up to 90 percent of the volume by the 22nd century threatening the key catchment areas Engadin, Ticino, Rhone, Rhine, and many more. This increasing documented loss of ice volume at the top of the mountains is due to the major impact of climate change.

Due to increasing temperatures and an increase of water irrigation, it is crucial to know for what the water is being used. When analysing Switzerland and comparing regions to one another, it shows, that the Greifensee catchment region is one of the few that irrigates exponentially more than the rest of Switzerland. The catchment area of Greifensee and the larger region Glattal have a rather high percentage of agricultural land compared to the other regions. With this it is normal that the irrigation is exponentially higher compared to others. This demonstrates how agriculture needs to adapt and become more sustainable for the near future. To get a grasp on the region of interest it is necessary to distinguish between three types of irrigation uses: vegetables, artificial meadows, and agriculture. The last being all farming activities (for example fruit or husbandry) excluding vegetables. All these different categories are sorted by the amount of average water they use to sustain the expected yield.

At this point all the pollutants such as fertiliser and pesticides come into play. Besides irrigation the use of pesticides and fertilisation can increase the yield of the crops. However, the use of fertiliser and especially pesticides is highly controversial and hotly debated. The article from the Tages-Anzeiger (17.9.2020) demonstrates the political topicality but also the missing transparency concerning these substances. The use of pesticides in the Canton of Zurich has even been linked to the death of children.

As we are now aware, a wide variety of influences on different scales are impacting the water balance in Switzerland today. The reasons for taking action against the increasing risk of water scarcity and loss of existing resources are growing. Different discussions range from philosophical to very technical approaches.