How is climate change affecting groundwater? – Experts have now discussed this for the first time in Güstrow. There is no clear trend yet. But the drinking water is safe, says the minister. But this is not a sure-fire success.
Güstrow (dpa/mv) – State Environment Minister Till Backhaus (SPD) is certain that the drinking water supply in Mecklenburg-Western Pomerania is secured despite longer dry periods as a result of climate change. Around 850 million cubic meters of groundwater are formed every year, Backhaus said on Wednesday in Güstrow. Backhaus told around 100 guests at the first “Climate Change and Groundwater” symposium that this is ten times the raw water withdrawal in the north-east, which also includes drinking water.
In order to increase the formation of new groundwater, the minister called on the agricultural sector to keep rainwater in the landscape much longer, especially during the winter months. To do this, so-called receiving water ditches, through which rainwater would otherwise flow into rivers and the Baltic Sea, would have to be dammed up. That’s missing so far. Farmers and nature would have to prepare themselves better for the spring and early summer dry seasons caused by climate change.
The crop rotation, i.e. the cultivation of crops, would have to be better adapted to climate change – which leads to longer evaporation, said the minister. The water law planned for MV will be presented shortly. It would name fees for groundwater, which should be charged to farmers, among other things. “What doesn’t cost anything is no good,” the minister explained the measure. Backhaus in Güstrow did not name a sum.
The groundwater developments are underpinned, among other things, by 680 measuring points in the state and measurements at the lysimeter in Groß Lüsewitz near Rostock over a period of around 50 years, said Konrad Miegel from the University of Rostock. Basically, the annual amount of rain in MV is almost constant, said Backhaus. But the rainy seasons have changed, it rains more in winter and there are more heavy rains in summer. So that the water can also reach deeper layers, it has to be kept in the landscape.
In the northeast, the drinking water for 85 percent of the population is obtained from groundwater at a depth of 20 to 100 meters. Only Rostock gets its drinking water from surface water, from the Warnow. Slightly falling trends in groundwater in deeper layers were registered at measuring points in West Mecklenburg and in the district of Rostock. From this, experts also derive lower water levels in groundwater-fed lakes such as in Neustadt-Glewe and Schwerin.
