The trap includes a container with a top opening covered by a lid. Inlet and outflow pipes extend through the lid into the container. A sheet of mesh filtration material (fiberglass, foam etc.) is situated within the container, below and preferably bonded to the interior surface of the lid. The inlet and outflow pipes extend through the filtration sheet into the container such that as the water level rises, sediment from the water flowing through the container settles to the bottom of the container and floating particles on the surface of the water which would otherwise be carried out of the trap with the water as the water exits the container remain in the filtration sheet.