Whoa! That's incredible. A kid in my high school died during junior year from a 30ft fall while he was riding his ATV. I guess it all depends on how and where you fall, not the height. I think Mythbusters did something like this on whether landing on water is softer than landing on sidewalk(it's not).
I remember that episode. Damn, Buster was MESSED UP! I never thought that landing on water could be so devastating.
I wonder if you made yourself straight as an arrow and fell down with your feet first into the water from an insane height, whether you could survive that way.