Abstract: A catch basin for draining water into an underground drainage conduit through a riser includes a receptacle having an open top and a base portion; an integral outflow conduit extending upwardly from an outlet opening in the base portion and having an inlet opening within the receptacle; and a trough in the receptacle that extends along a side of the base and below the level of the inlet opening to provide a trap for debris contained in water flowing into the receptacle. The receptacle tapers inwardly from top to bottom, so that a first receptacle can be nestably stacked in a second receptacle.