Butte County's Storm Water Management Program is a requirement of Phase II of the National Pollutant Discharge Elimination System (NPDES) Program as ordered by the United States Environmental Protection Agency. The County's Program was required by federal law to be fully implemented by April 30, 2008. Part of this implementation is to mark all existing and newly installed storm drains. Shown below are the markers that will be used.

Used to identify drainage to creeks

Used to identify drainage to groundwater