Pumps are essentially reversible generators. They have all of the functions of a generator as described in the prior page. They also have the ability to run in reverse.

The pump table is identical in structure to the gated generator table.

To differentiate between pumping and generating, simply feed the pump a negative flow. This is best done by creating a rule that places a negative demand on the outflow slot of a reservoir. It may also be done by supplying negative values in the user series of the outflow slot of a reservoir. If the tailwater is above the outlet elevation and the head difference is within the operating range, it will move water upstream.