How does stormwater flooding cause my sanitary sewer to back up? Are there not two separate drainage systems?
Because sanitary sewers are not watertight, stormwater can get into the sanitary sewer in a number of ways: • at manholes, through manhole covers, and through cracks and voids around the manhole • from the surrounding ground, through cracks or separations in the sewers and from private service connections • from weeping tile (foundation drainage) systems at private homes and buildings, since poor lot grading contributes to weeping tile flows • from downspouts that have been incorrectly connected to the sanitary sewer system rather than the storm sewer system. Also, during larger storm events, like the ones that occurred in July 2004, much more water pools on the surface than normal. This can cause an increased amount of water to enter the sanitary sewer.
