A catch basin is a stormwater tanks with storage chamber and pool skimmer , but without Klärüberlauf . In this basin, polluted rainwater ( rain clarification basin ) or mixed water ( rain overflow basin ) is temporarily stored and forwarded to the sewage treatment plant in a throttled manner . The amount that cannot be stored in the basin is released into the receiving water via the basin overflow . Catch basins may only be arranged if there are no previous reliefs in the network above.
In contrast to continuous basins, catch basins are built if the catchment area is so small that a substantial part of the pollution can be stored in the basin and it can be expected that the pollution of the incoming wave is so low that it is harmless to the receiving water.
see also: cistern