Power it off fully, if not already. Open it up, if you can manage (and stomach it). Dry up what water you can (be careful not to damage anything). Do the bag of uncooked rice trick, dry in a warm (not hot) area for a few days if you can. Then try to power on.
When devices are exposed to water, its totally random whether it will work correctly or not. It might function perfectly, it might not work at all, or it might work but some things may be screwed up. Or it might work fine for a while, and then just stop working. It all depends on how much water got inside, where it went, it if caused a short circuit or corrosion inside, etc.
My wife dropped her iPhone 5 in the toilet pretty soon after its release. She put it in a bag of rice, and took it to the Apple Store, where the Genius Bar tech took it apart and dried it as best as they could. Its been working fine ever since.
Please click the "Thanks" button if you found a post helpful!
Phone: HTC One X (AT&T version) Rooted, Bootloader Unlocked, S-Off
Tablet: Samsung Galaxy Note 8 (WiFi only) Rooted