There is no doubt that owning a water pump can come in very handy for a number of reasons. Maybe you live in an area where flooding occurs regularly and need submersible pumps to help clean up afterwards, or are interested in water pumps to fill your swimming pool. Perhaps you need it for everday use in pumping up water from a borehole or water well. Whatever the need for purchasing any water pump, you should think about your specific requirements so you choose the correct one: 1. GPM Discharge Capacity All water pumps are measured in GPM Discharge Capacity