"People with houses on the river banks downstream including Jakarta have to be on the alert," water gate officer in Depok Ardi said here on Thursday.
The Cilwung river empties into the Java sea through Jakarta.
Ardi said people living in the Ciliwung river banks are feared to have another flooding in six to 8 hours.
"The water surface reached a level of 380 centimeters at the Ciliwung water gate at 04.00 this morning," he said.
At the Katulampa dam that also holds the water from the Ciliwung river , the water surface had also increased to reach a high level of 220 centimeters at 23.26 on Wednesday.
Ardi said the water volume in Ciliwung could rise anytime depending on the intensity of rain fall especially in the upstream area of Bogor, where rain has continued to pour.
It would take 3.5 hours for the rain water to reach Depok via Ciliwung river, he said.
He said the Depok water gate officers have continued to coordinate with water gate officers in the Katulampa dam of Bogor as well as those in the Manggarai water gate in Jakarta. (*)