A watershed is an area or ridge of land that separates waters flowing to different rivers, basins, or seas. The watershed has a big impact on the hydrologic system because to get water the hydrologic system uses evaporation and then precipitation(this is also used in the water cycle). Finally, Flint Michigan crisis could have gotten prevented if they didn't switch their water supply in their watershed.
The Water Cycle uses many resources like the atmosphere, geosphere, hydrosphere, biosphere. Also in the hydrologic system, the water cycle is used like volcanic steam, atmosphere, oceans, and even precipitation.
The Flint water crisis began in 2014 due to the insufficient water treatment. Also since Flint switched their water supply to Flint River. In hydrology, there's something called a watershed and when the flint crisis happened because they switched their water supply.