There is disclosed a water treatment apparatus for treating stormwater, the water treatment apparatus comprising a volume of filter media, a baffle and an inlet conduit. The baffle extends upwards from the volume of filter media and defines a pre-treatment zone on one side of the baffle and a treatment zone on an opposing side of the baffle. The inlet conduit opens into the pre-treatment zone and is separated from the treatment zone by the baffle. The baffle is configured to regulate a flow of stormwater received via the inlet conduit by controlling the passage of stormwater from the pre-treatment zone to the treatment zone.