A catch basin filtration system having a filter body dimension to fit within a drain inlet forming a trough or reservoir obstructing at least a portion of the inlet. The filter body is supported by a filter body support dimensioned to cooperatively engage with the interior walls of the inlet and with the filter body to substantially maintain said filter body in a pre-selected shape and position within the inlet. One or more connectors removably connect the filter body to the filter body support. One or more adjustable high fluid flow bypasses prevent the system from backing up and flooding surrounding areas during periods of high fluid flow.