La Habra police, Los Angeles County firefighters, and Orange County Public Works officials responded to the scene after the sinkhole, measuring 20 feet by at least 80 feet, was reported about 10:45 p.m. in the 950 block of West Imperial Highway.
Residents said it sounded like an earthquake.
"That's what I thought it was, an earthquake," said Reina Menchaca of La Habra.
The sinkhole toppled multiple trees, including a towering one that landed on one of the condo buildings, causing some damage.
Three residences were under voluntary evacuation orders, police said.
"The cause of the collapse appears to be an underground flood-control channel that collapsed, causing the green belt above to fall into the flood-control channel," police said in a statement.
Officials are trying to determine whether the area is public or private property, which will determine who will pay for the cleanup.
Residents were encouraged to avoid the taped-off courtyard until it was deemed safe. No injuries were reported.