The water supply of Earth is a required element for life to exist and thrive. The water cycle is a continuous cycle that keeps water moving on and around Earth in different forms.
Here are some links to learn more:
https://www.123filter.com/ac/water-pollution-how-humans-impact-the-water-cycle
https://www.youtube.com/watch?v=jjPfLhJbdc0
https://www.watershedcouncil.org/stormwater-for-kids.html
https://water.usgs.gov/edu/watercycle-kids-beg.html