The floodgates have been opened for the first time in years to test the system.
"The engineers designed certain parameters for certain flow of water, certain amount, certain speed," said Greg Fuderer with the U.S. Army Corps of Engineers. "What we're doing now is testing the outlet gates and the outlet tunnels to make sure that they operate according to the way they were designed."
Inside an underground control center, engineers vary the flow rate, cranking it up to a maximum of 2,500 cubic feet per second, which would fill up an Olympic-size pool in a couple of seconds.
Thanks to abundant rain from the winter storms, there's enough water in the reservoir behind the dam to allow the engineers conduct the operation.
Five years ago, the dam was damaged during testing. Now the problems have been repaired.
The Seven Oaks Dam is the largest dam in the inland region, intended the protect Orange, San Bernardino and Riverside counties from a catastrophic flood.
"One of the worst floods in Southern California was along Santa Ana," Fuderer said.
The tests will continue for a couple more days and so far, everything is going well.