THE ubiquitous plastic bag is being blamed for many of last week's floods, which caused traffic chaos in Central and Wan Chai. But a spokesman for the Drainage Services Department ruled out any special measures to combat the plastic menace ahead of this year's monsoon season. ''Much of the flooding in urban areas is caused by plastic bags and other material which cover and clog drains,'' said spokesman, Varren Lee Man-ngok. ''We do have teams to deal with the floods as they occur, but there is very little we can do specifically against plastic bags,'' he said. One of the worst-hit areas during last week's deluge was along Conduit Road, when plastic bags blocked underground pumping equipment that helps force stormwater into the harbour. ''There was nothing wrong with the pumps, they were just clogged with bags and unable to work,'' Mr Lee said. Drains and sewers are inspected by department engineers before the monsoon season to ensure they are not blocked by rubbish and other material. In the last deluge, nearly 100 cases of flooding were reported.