A Guide for Sustainable Urban Development of the 21st Century

Shanghai Manual – A Guide for Sustainable Urban Development in the 21 st Centuryraising concerns about the possibility of disease. Reports in the media warned of the threat ofwaterborne diseases, and hospitals and health centers geared up to distribute free medicines incase of any outbreaks.Suburban train systems were completely disrupted. Road traffic was chaotic where the streetswere still useful, but many major roads were completely flooded. The airport closed for twoconsecutive days. Electricity service was shut off to avoid electric shocks. Damagedinfrastructure included 50,000 residential buildings, 40,000 commercial establishments, and30,000 vehicles (cars, trucks, buses and trains)Apart from the heavy rains, three factors contributed to the scale of the disaster: an antiquatedstorm-water drainage system, uncontrolled and unplanned development in the northern suburbs,and destruction of mangrove ecosystems. The drainage system was extremely inadequate interms of potential flow rate and it was clogged in several places. Ninety-seven per cent of theoutflows to the sea were not equipped with floodgates and as a result, there was no way to stopthe seawater from rushing into the drainage system during high tide. Development in the northernsuburbs of Mumbai is haphazard and buildings are constructed without proper planning. Thedrainage plans in those suburbs were developed in an ad hoc manner, not systematically.Mangrove ecosystems which exist in and around the city were being destroyed and replaced withconstruction. These ecosystems serve as a buffer between land and sea. It is estimated thatMumbai lost about 40 per cent of its mangroves between 1995 and 2005, some to builders andsome to slums.After the 2005 floods, the local Disaster Management Office designed a plan to reduce theimpact of future extreme weather events. Most of the efforts related to flood control. Substantialpublic works were undertaken to de-silt the entire sewerage system. This included microtunneling to ensure adequate discharge of monsoon water at several chronic spots, and cleaningof railway culverts. Flood-gates and sluice gates were installed and manned to operate duringhigh tide and low tide. Twenty-six automatic weather stations with rain-gauges were installed tomonitor the system. The Mithi River was dredged to widen and deepen its channel. Finally, 85pumps were installed at chronic flooding locations; these are manned by operators withcommunication systems.35