Manila, Aug. 20 -- The Department of Environment and Natural Resources (DENR) warned that improperly managed garbage can worsen flooding during heavy rains, urging local government units (LGUs) and the public to keep waterways free from trash and to learn from experiences, as the southwest monsoon or "habagat" is expected to continue affecting parts of the country through September.

In a news release Thursday, Environment Secretary Juan Miguel Cuna said waste that ends up in canals, creeks, rivers and drainage systems obstructs water flow during heavy rainfall and is eventually carried into coastal areas and the Manila Bay.

"Habagat is a natural phenomenon, but the waste that ends up in waterways is something that can be prevented. Ever...