Where is the water coming from?

There must be a valve somewhere. Is it well water or under pressure from a municipality?

Is it a well? Has it been raining a lot lately?

I have well water. No, not too much rain.

Is this pipe a drain or a supply? Maybe the barn is lower than the surrounding water table and there is back flow going on. Not connected at all to the city water mains?

If you aren’t sure of the source or how to control it, what about calling a plumber? Wouldn’t they know what to do?

This is really curious.

A pipe “extending out of” the floor in the bottom of the barn doesn’t sound much like a drain. Normally a drain pipe would be cut flush with the floor, and would be located at the lowest part of the floor, and covered by a filter or screen plate of some kind so that it doesn’t try to drain things that shouldn’t be put down the drain pipe..

This could be intended as an overflow protector drain for, say a tank. Just like your bathroom sink has a hole near the top edge that allows water reaching that level to run to the drain, this pipe may have been intended as protection against a tank in the bottom of the barn from filling past that point.

Or it may be a fill pipe for a tank located in the bottom of the barn. There’s no way for me to know without some more detail.

If the pipe runs directly into the floor and is buried from that point on, with no valve visible or available, then it’s more than likely intended as a drain pipe (fill pipes always have valves somewhere, drains may or may not be valved). It’s also possible that it’s a supply (fill) line from your water source (pump, tank, etc.) and it has a buried valve (like municipal water supply valves for homes are often buried below street level, with small covers in the roadway that can be removed so that a tool can be inserted from street level to open or close the valve, as needed – and that valve is 99.999% of the time open so that the water will flow to the house). Just because you can’t see it doesn’t mean it’s not there. (I wouldn’t expect such a setup on a farm, however, as it’s just too elaborate, expensive and unnecessary.)

I’m guessing that it’s a drain, then, and your drain is backing up on you for some reason.

I agree with @Pied_Pfeffer . Call a plumber then come back and tell us what they said.
Is there a pump on your well that could be stuck?

If there is a cistern under your barn it could be an overflow or relief pipe that prevents the cistern from buckling the floor of the barn if it gets too full.

Hmmmmm . . . a plumber means moola that I don’t have at the moment. And a flooded Barn floor means future foundation problems and more moola.

I turned off the well pump and the water stoped. Maybe I messed a valve in my basement that controlls this thing?

I’ll get a plumber if after i’ve double checked all the turnoff in my basement and it’s still running. Will post the results here. Thanks All!!!!