Storm drains, catch basins and lines from a storm sewer system to redirect run-off created during a rain event. They are not a sanitary sewer, where wastewater from toilets are sent to a treatment plant to be cleaned.
Storm sewers redirect runoff formed during rain or snow events into a system of catch basins and pipes. Storm water run-off often carries gravel, plastic bags and bottles, leaves and sticks and other street debris. This material often runs down the system after a heavy rain, creating buildup within the storm sewer system. When the rainwater can no longer flow down a system because pipes and culverts are blocked, streets will become flooded, which creates hazardous or impassable travel conditions. Many storm drain systems use gravity to keep the flow going, until they reach an emptying area, which is often rivers or streams.
A catch basin is the central piece in a storm drain system. These ‘boxes’ are buried ground level and feature a grate that allows water and debris to enter. The water escapes through a outlet trap into a underground piping system, while the debris settles in the bottom of a basin. Once enough solids accumulate (typically about a third of box), the catch basin must be cleaned out.
A catch basin that is routinely inspected and cleaned, prevents standing water and maintains a clean and fee-flowing storm line system.