If groundwater tables drop, streams pollute drinking water
Increasing drought, less precipitation, rising water demand in agriculture—climate change is causing problems for our groundwater. In Germany and around the world, it is leading to falling groundwater levels in some regions. When the underground water table is low, polluted surface water from streams and rivers finds its way more and more into the groundwater. The result: Our drinking water and groundwater ecosystems are endangered—making a problem of quantity a problem of quality too. This is what researchers are currently describing in the scientific journal Water Research. Their recommendation: new research approaches and regionally adapted concepts to improve groundwater formation.
"We see a direct consequence of climate change here, whereby our most important water resource—groundwater—is at risk," says Hans Jürgen Hahn from the University of Koblenz-Landau, one of the authors of the study. In many areas around the world, the groundwater tables are dropping more and more, as the recharge rate is also declining. At the same time, groundwater extraction are increasing on account of agricultural irrigation and for drinking water supply. This results in an additional lowering of groundwater levels, coupled with a change in the regional landscape water balance—causing climate impact to spiral downwards ever faster.