Sump:

The sump is a depressed portion of the collecting basin from that cold water is drawn to be returned to the linked system. A sump commonly holds antivortex devices, strainer screens, and a drain or cleanout connection.

Distribution system:

The distribution system is that portion of a cooling tower which distributes water over the fill area. It commonly consists of one or more flanged inlets, internal headers, flow control valves, distribution basins, metering orifices, spray branches, and other associated elements.