A study has revealed that climate change is affecting drinking water quality. Heatwaves, drought, floods, forest fires - the consequences of climate change are increasing and are changing our environment. A prime example is a countryside in the catchment area for the Rappbode reservoir in the eastern Harz region. This is the largest drinking water reservoir in Germany and provides drinking water for roughly one million people. Forests play a key role in the water cycle. They filter the water and bind nutrients and are therefore necessary for good water quality.