To see a sewer in your dream signifies putrid conditions and old relationships. Something needs to be cleaned up or immediately changed. You need to let go of your outdated ideas and beliefs.
To see a sewer pipe in your dream represents the flow of subconscious material being suppressed deeper and deeper. You need to address these issues before it overflows.
Dreaming about a flood with mud and/or garbage coming out of the sewer indicates that your feelings are repeatedly being belittled, undermined or unacknowledged. You feel disrespected.