Why is it necessary to protect reservoirs, rivers, conserve water?

Unfortunately, water resources can already be classified as scarce. On our planet, not all inhabitants are provided with simple drinking water. The springs dry up due to man-made reasons: violation of the integrity of the earth’s crust due to mining, landscaping, construction of roads and bridges. And those water bodies that have not yet dried up often turn out to be polluted. This is the fault of factories and plants that fill water bodies with harmful chemicals that endanger the life of all living things.