The Orange County Crime Lab concluded that Alan Sun-Long Lin's post-mortem blood alcohol content was between .16 and .19 percent.
A man of his size would have needed to consume seven or eight alcoholic drinks in one hour to reach that level, reported the Orange County Register.
The 22-year-old mechanical engineering student at the University of California, Riverside was found floating in the Rhine Channel on Feb. 13, eight days after he was reported missing.
Lin, who lived in Riverside during the week and returned to his family in Orange County on the weekends, had last been seen leaving a bar about three blocks from the bay.
The Associated Press contributed to this report.