Authorities had temporarily closed the street afterward so cars wouldn't splash any of the sewage, she said.
As a precautionary measure, the Orange County Health Care Agency closed Little Corona. The beach sits next to the mouth of Buck Gully, about three miles south of the spill.
It took water district officials 90 minutes to contain the spill through a secondary pipe. In that time, at least 18,000 gallons spilled into Buck Gully.
The gully was dry though, so it doesn't appear the leak contaminated any water flowing into the ocean, said Mike Fennessy of the health care agency.
County health officials tested the water by Little Corona on July 3 and 4, with both showing the water was OK, Fennessy said.
Little Corona reopened before 11 a.m. Monday.
Lifeguards said the closure over the Fourth of July weekend didn't cause any problems because the beach is small and difficult to access, making it more popular with locals than out-of-town guests who flock into Newport Beach for the holiday.
"It didn't create that much of a hassle," said lifeguard Battalion Chief Mitch White. "It only gets 100 to 200 people on a crowded weekend."
Water district workers replaced the ruptured pipe Monday and are examining the damaged pipe to figure out what went wrong, Reed said.