Drains work by using simple gravity. When you push down the sink plunger, the drain sucks water through the opening into the appliance drain line. As the water falls straight down the vertical appliance line, it gathers speed and velocity. That speed allows it to move past the p-trap and into your home's drainpipes.

What are water drains used for?

Drains receive water from street gutters on most motorways, freeways and other busy roads, as well as towns in areas with heavy rainfall that leads to flooding, and coastal towns with regular storms.

Where does water go when it drains?

Where does the water go after you flush the toilet or drain the sinks in your home? When the wastewater flushed from your toilet or drained from your household sinks, washing machine, or dishwasher leaves your home, it flows through your community's sanitary sewer system to a wastewater treatment facility.