When i pour water in my radiator, it runs straight out under the car

could be the water pump but I would be looking for a larger leak, like a radiator hose, radiator tank split
most water pumps leak a slow dribble and then mostly when running
have a pressure test done on the cooling system to find the exact location of the leak

these cars have a water pump in the front center of the engine and when it leaks cant see it couse coolant or water runs to the back of the engine between the heads thats one but did you change the thermostat and or radiator cap? try with that first but is a good chance that you have a water pump problem.

it may be the hose itself, or the radiator, or a nearby line that lead from the radiator to a heater core, or a broken plug in an un-used port, or even a bad radiator cap - it depends where the water is actually coming from. is it coming from the hose or from where the hose connects to the radiator, or is it pouring down from somewhere else and just pooling under the hose.

Check the front corner of the intake gasket. Very common problem

Remember that coolant is poison, so many places (communities) really frown on draining the coolant onto the ground or pouring it down the drain, as it pollutes the water supply.
In some communities it is illegal.
Myself, I usually reuse it, because of the above.
If it is old, add "water pump lubricant " and "anti-foam.anti/rust" to "rejuvenate it".
Find the drain on the radiator, should be at the bottom of the radiator, and may be really hard to find.
Usually it is on the opposite side than the lower radiator hose connection.
The slow way is to open that drain and put a garden hose in the top of the radiator and keep the radiator full as the motor is running and the heater is on full blast.
Doing it this way should take half an hour or more. You are looking for the water running out the bottom of the radiator to be clear and tasteless.
Tasting it after it is running clear will help determine if the collant is all gone.
A tiny drop to taste will not hurt you.
Coolant is "sweet" tasting.
A faster way, and much more work, is to remove the top end of the radiator hose that attaches to the radiator to drain the system.
You will need to plug the top radiator hole where you took the hose off with a rag or something, and run a hose from the loose radiator hose to wherever you are wanting the "waste" water to go.
You still must keep the radiator full as you run the motor.
This way should take 5 minutes of flushing after the thermostat opens and the water starts flowing.
After the water runs clear. turn off the motor and the garden hose that kept the radiator hose full.
After all the water stops running out, close up everything, and fill the radiator with straight coolant, not the 50/50 blend, because you will have the motor full of water, and adding straight coolant will give you your 50/50 blend when you are all done.
Be sure to leave the heater on full blast, and run the motor for 5 minutes to "burp" the air out of the heater.
Be blessed.

Check the condition on your hoses attached to the radiator. Does it only leak with the engine running? If it comes out right away, have some add water to the coolant reservoir while you check where the leak is coming from...this would be a cheaper way to diagnose it (water is way cheaper than coolant). Make sure you have a bucket or a tray under the car to catch any fluids that are leaking. Also, make sure you dispose of coolant properly (do not pour down drain, take fluids to a local repair shop) Scott

you need to replace thermostat and radiator cap.look under hood around engine compartment.look for a radiator cap near radiator,add 50/50 antifreeze and water to coolant system to bring up boiling point.pure water will cause engine run hotter because water evaporate away,remove radiator pour coolant in the radiator until coolant stop dropping in the radiator now some vechicle pour coolant in the coolant overflow jug,pour coolant until coolant level stop dropping and the coolant level stay at cold full mark.start engie let idle few minutes, watch coolant level in radiator if coolant start dropping add more coolant, when coolant level stop dropping put radiator cap back on let engine idle until both top radaitor hose and bottom coolant hose get warm turn off engine wait until it get cool then take a large rag slightly open radiator just a litle at a time to keep from getting scaled.once radiator remove add more coolant if low,put radiator cap back on start the engine let it idle watch the temp gauge if temperature gauge going hot zone stop engine wait until cool then add more coolant,keep doing this until engine stop overheating going into hot zone and coolant level stop dropping,make the coolant overflow jug coolant level stay at full cold mark, dont let jug run empty if so air will get in the coolant system causing engine to overheat.

either your bottom radiator hose is loose or off or you need a new radiator cause its got a hole in it.

You may need to "burp" the system and get the air out. When car has completely cooled, take radiator a off, start car, let it warm up (but not overheat) and see if level drops. Add coolant/water mix to top it off. Never run straight antifreeze. At most a 50/50 mix of distilled water and antifreeze.
Air can get trapped in areas of the system when its been drained. Just monitor that temp and don't risk damaging the engine by overheating.

you need to get it checked out by someone with mechanical knowledge as it may be a freeze plug or cracked pump housing, burst radiator, just try to see where the water is coming out if you can while you pour it in.