When a water pump goes bad the water pump will usually make a squealing or squeaking noise that gets worse and louder as you accelerate.
The squealing or squeaking noise when the engine is running is a sign that the bearings in the water pump are going bad.
Once the bearings start going bad in the water pump it's time to replace the water pump because if you don't the water pump will eventually seize up and break your serpentine belt and leave you stranded.
Also another sign of a failing water pump is a coolant leak coming out of the weep hole.
The weep hole is designed to leak coolant out alerting you to failing seals in the water pump and when that happens the water pump needs replaced.
Look towards the back of the water pump at the bottom of the water pump to find the weep hole and if there's coolant coming out of the water pump then its bad and needs replaced.
Do not plug the weep hole as it can cause more damage.
A failed water pump will lead to engine overheating as well.