Leaking water pump?  Usually if the pump begins to leak the majority of the time it will be a failed mechanical seal, this device has a sacrificial carbon face which fits into the pump housing and works by trapping a thin layer of product liquid between the two polished faces, when the shaft/impeller rotate it then creates a seal against the mating face. The mechanical seal is situated between the pump wet end and electric motor, this forms a seal around the motor shaft to prevent pressurized liquid from escaping and is the main wearing part of any pump.
A mechanical seal may leak liquid if the pump is ever run dry or eventually wear out, if not replaced promptly liquid will travel along the shaft and ruin the motor in a very short period of time.