Video posted to YouTube shows that Smith landed near the pool, and then rolled into the water.
Smith is now listed in "fair" condition after his brother told 9NEWS the sophomore broke multiple bones in the fall.
911 calls show that the students who called for help did not know Smith.
"He was trying to jump into the pool, but he missed it," says one caller.
"You need to come to Ram's Village pool, someone just jumped off the roof into the pool!" she said to the dispatcher on the other end.
"He jumped off the roof of the pool, and missed the pool, and hit," said a caller.
"He jumped off the roof of the building?" asked the dispatcher.
"Yeah," said the caller.
"Was he horsing around, or why did he jump off the roof?" asked the dispatcher.
"Uh--I don't know. Next thing I know he's on the roof, I don't even know him. There's just a bunch of people," said the male caller.
Witnesses say most people were trying to persuade Smith not to jump.
"Is he on the concrete or did he hit the water, or what?" asked the dispatcher.
"He hit the concrete and then landed in the water," said a caller.
Smith was taken to Medical Center of the Rockies in Loveland.
According to Ian Smith's Facebook page Monday is his 20th birthday.
His brother tells 9NEWS Smith has two broken ankles, two broken heels, and multiple broken vertebrae in his lower back.