What are your flood-prevention criteria? (Civil Works)
DORTS has been enhancing systemwide flood protection on its exclusive right-of-way and underground routes. The design criteria for various flood prevention schemes in different cities vary in respect to urban characteristics. For example, flood-protection measures were set up in Osaka, Japan to prevent flooding during high tides in Osaka Harbor; in Washington D.C., to protect against overflow from the Potomac River and high tides in Chesapeake Bay; in Zurich, Switzerland, to protect against the overflow of lakes and rivers; and in Taipei, to protect against the flooding caused by rainstorms. Therefore, after overall evaluation of the factors involved, such as the functions of Taipei MRT facilities and their lifespan, the risk to safety, engineering economics, etc., DORTS adopted an estimated flood level for a return period of 200 years plus an additional 110 cm. All entrances to stations, structural openings, and depots were designed based on this criterion to prevent flooding.