"Logs and whatever debris is there, if a shell hits that it could be very damaging," Regatta secretary Bob Morro said.
Because of the fast moving current there were some changes to the race this year.
Regatta officials shorted the course by 500 meters.
Also rowers won't be racing head to head against other teams.
The swollen river means that teams will start each race 30 seconds apart.
"They changed it to a head race, which kind of means like time trials in track. So it makes it fair for everybody, the current's not a big issue, and every body has the same conditions," Villanova junior Brianna Ipjian said.
The Dad Vail is the Super Bowl of collegiate rowing and, despite the changes, the competition is fierce.
Teams have worked all year long to get to this moment.
"It's kind of like the race of the spring season to go to and for me it's always been like the biggest race we do," St Thomas College of Minnesota senior Jim Portman said.
"It's so great to see all these colleges competing. It's really an honor to be able to bring a boat here," North Carolina State sophomore Erin Morton said.
For some parents this may be the last time they get to cheer in the stands.
"For most of the kids, this is the culmination of the entire year for them. This is the largest regatta for our daughter, so probably, the last time she will row," Bill Sweet said.
The regatta will hold semifinals and finals in the traditional style.