Polluted water creates numerous costs to the public and to wildlife. Communities that use surface water for their drinking supply must pay much more to clean up polluted water than communities with uncontaminated water sources.
Polluted water hurts the wildlife in creeks, streams, rivers and lakes. Sediment covers up fish habitats and fertilizers can cause too much algae to grow, which uses up the oxygen and blocks light aquatic plants need to survive. Detergents and chemicals hurt aquatic creatures and can affect reproduction.
The amount of runoff is also a problem. When stormwater falls on hard surfaces like roads, roofs, driveways and parking lots, it cannot seep into the ground, so it runs off to lower areas. Because more water runs off hard surfaces, developed areas can experience local flooding. The high volume of water also causes streams banks to erode. To give you an idea of the difference a hard surface makes, consider the difference between one inch of rain falling onto a meadow and a parking lot. The parking lot sheds 16 times the amount of water that a meadow does.