A $285 million storage tank to prevent flooding in Kowloon West was unveiled yesterday. The system covers mainly Tsim Sha Tsui and Mongkok, where Nathan Road has been a flooding black spot during heavy rainstorms and typhoons. The 100,000-cubic-metre concrete tank under the Tai Hang Tung recreation ground in Shek Kip Mei will protect the two areas even if a rare 110-millimetre rainfall persisted for two hours, said Drainage Services director Raymond Cheung Tat-kwing. Combined with the Kai Tak transfer tunnel and local drainage improvement works earlier this year, the tank means the flooding problem in Nathan Road has been resolved, said Mr Cheung. The 32km drain that diverts storm water from under Waterloo Road in Kowloon Tong to the Kai Tak nullah in San Po Kong also helps reduce floodwater. The tank and the drain form the government's strategy to manage the water in the catchment area covering upstream Kowloon Tong, mid-stream Shek Kip Mei and downstream Mongkok, said David Cheung Yee-tin, a chief engineer of the department. 'The tank is sizable even by international standards, ' he said. To improve the hazard at the flooding black spot at the junction between Waterloo Road and Dundas Street in Mongkok, a box culvert is being built for completion next year, he said. Drainage improvement works at the junctions at Waterloo Road and Peace Avenue, and at Nam Cheong Street and Tai Po Road are now being expedited for completion in 2005 and 2006 respectively.