HELP! Koi pond pump went out

I have a 7,200 gallon koi pond in my backyard that is has a biofilter and pump that cycles the water out at one end where the skimmer is, and over a waterfall for aeration and back into the pond at the other end. Today I went out to discover that the waterfall had no water running over it. I know there is still power going to it because the UV filter light is on and I can still feel vibrations near the intake. Also, there is some water being pulled in. Do you think there is a clog somewhere in the line or could the pump be having problems? The fish seem ok right now but I don't know how long they will survive without the waterfall running? Any advice is appreciated!

How many and how large are your Koi? No-one can answer your question without this information.
Also where are you? Climate plays int this scenario.

pull your pump up and look at the intake if you still feel a vibration something may have stoped your impeller. when you pull it up open the bottom turn it on see if it moves,,you can back flush it with a water hose...

I went out this morning in the light of day and found the problem very easy to fix. The pump intake was just completely clogged with grime and debris. I unplugged it, took it out, cleaned it off, and put it back in place and voila, the waterfall started running shortly thereafter. I'm glad it wasn't something more serious. Thanks for the advice! BTW, the fish are doing fine, we have about 15 koi that are from 6 inches to over a foot in length, as well as two algae eaters (plecos) about 8 inches long. The high temp outside today is about 55 degrees F.

Fine deal, looks like you are good to go now.

FYI, with 7200 gallons and that low temp with so few Koi, you would be fine for a week, maybe a lot longer. There are those who will argue this, but there are hundreds of natural ponds that don't have all you have going for them with thousands of fish in them doing just fine.