The hydrology cycle is the cycle that is all about water and how you can get to a watershed. This cycle can go through many different paths and get to the same thing.
A watershed is all of the land that drains into the same location or body of water. Watersheds always are downhill and everybody has a watershed in there state.
The flint water crisis started in 2014 when the Flint river was changed insufficient water treatment over 100,000 people were potentially exposed to high levels of lead in the water.