What is storm water runoff?

Storm water runoff is generally recognized as the single largest threat to water quality in the United States, whether in a rural or urban setting.  Rain is not the problem.  But the pollution that rainwater picks up as it runs over manmade surfaces pollutes our swimming holes and poisons our drinking water.  Surges in rainwater that are channeled directly into our waterways through storm drains increase the magnitude of floods.  Storm water runoff alters the amount, quality and temperature of water in our rivers and creeks.  Storm water runoff fundamentally changes the natural circulation of water – the hydraulic cycle that most people learned in elementary school.