The issue with this is that it's important for water to filter through the ground before it gets to our waterways! The ground filters out chemicals and pollutants and it also slows down the flow of water. When there's more impervious land, the water moves into the rivers at a faster rate, causing more erosion of the river basin and increasing turbidity (how cloudy water is). Dirt and other debris also get pulled into the river since the water isn't filtering through the ground, this causes sediment to build up in the bottom of river making it shallower and shallower and more mucky. Imagine being a fish trying to breathe in mucky water!