Doesn't that depend on how far downstream you are? If you are upstream from the Anacostia and from Four Mile Run, is there really enough Combined Sewer Outflow to matter?
There are currently 10 outflow points between the Key Bridge and the 14th St bridge, and each point has an overflow warning. There are also 24 outflow points in Rock Creek.
DC Water has a plan to extend the Potomac River Tunnel all the way down to the wastewater treatment plant near Alexandria, and also to separate the sewers along the various outflows of the Potomac -- this should alleviate a lot of the overflow along the DC side of the Potomac, however that infrastructure won't be built for a while.