Storm Drains

Storm Drain Covered by a Metal GrateA storm drain is very different from the drains inside a home. Any water that leaves your house through a kitchen or bathroom drain flows to a sewage treatment facility. At a sewage treatment facility, the water undergoes a cleaning process.

Water that flows down a storm drain does not make its way to a water treatment facility. Instead, whatever flows down a storm drain flows directly to a creek, canal, lake, or other body of water.

Local Storm Drains

In Contra Costa County, storm drains flow directly to local creeks, San Francisco Bay, San Leandro Reservoir, and the delta with no treatment. Storm water pollution is a serious problem for wildlife dependent on our waterways and for the people who live near polluted streams or baylands.


In the Town of Moraga it is the resident’s responsibility to maintain the drainage structures on their private property. These drainage structures usually consist of concrete lined swales that empty into a catch basin that drains to the Town maintained storm drain system at the street.