How to know if water pump needs replacing on a 97 nissan sentra?

I have a sentra that is overheating when running on the street. I usually run this car around my property carrying hay and whatnot with no problems but whenever i have to go to the feed store it will start overheating when on the streets. could it be the water pump? i would hate to replace it and end up whith the same problem again......How to know if water pump needs replacing on a 97 nissan sentra?Start simple with a thermostat then work on the more difficult things. Make sure the condenser and Radiator are not plugged up with debris. Shine a flashlight from behind and look for light in front. 13 year old coolant hoses inside the Radiator could be clogged to.