The water pump is the heart of the cooling system and continuously keeps the antifreeze/water mixture flowing through the engine, radiator and heater core. If you think your car's water pump is going to break let's first look at how it could fail. The water pump can fail by leaking coolant past the pump shaft seal and out the weep hole, the bearing can become loose on the pump shaft and cause the fins inside to rub against the housing causing it to possibly lock up or break altogether or the fins inside may erode away from old antifreeze and not allow enough flow throughout the cooling system.
So how can you tell if the water pump is going to break? Any sign of an antifreeze leak, whether the coolant level is low or you find antifreeze on the floor, will tell you that there is a cooling system problem. You need to check in the area of the water pump and find the leak. If it's coming from that area or around the cover over the water pump then you will want to have it checked further. Make sure you find the source of the leak to eliminate problems later.
If your temperature gauge is showing the engine overheating then the water pump may be the culprit. Overheating can be caused by many things but don't rule out the water pump. In this case the fins may be too worn and not allowing enough circulation throughout the system to keep it cool or the water pump is just leaking past the seal and you have lost too much coolant.
If you hear a rough bearing (growling) type noise in the engine area, this may be the water pump bearing gone bad. If you are able to get to the pump you may be able to check for free-play in the pulley that turns the shaft on the water pump to see if the bearing is lose. If that's the case then the water pump needs replacing immediately.
Water pumps don't break as often as they used to, but keeping an eye on your coolant level and changing the antifreeze at the proper intervals will help you eliminate problems to the minimum. A broken water pump will quickly leave you stranded and may cause severe damage to the engine if you try to drive too far without the flow of coolant created by the pump. As always if you are worried about the water pump take it to a reputable garage where they can at least pressure test the coolant system and see if there is weakness in system anywhere.