Worst case scenario is a bent rod (or rods) and you'll need a new bottom end, head should be ok. Start doing some investigation to see if water actually made it into the bores. What engine is it?
I hope for your sake it is not hydro-lock, quite common during floods where people don't realise the effects of driving through deep water until it is too late. I crap myself when I see deepish water and do my damdest to avoid it!
went through a "puddle" just under 2 years ago in my 1st Zs 180. That was the end of that one. Had to have a new engine but I got paid off by the insurance company and bought zs 180 number 2. I have always avoided the smallest of "puddles" ever since.