Cyclone and Storm Surge - Iczmpwb.org

3.19
20 September 1990 275 24 hours
13 May 1913 25 10 minutes
26 September 1978 to
1 October 1978
735.30
5 days
(Maximum on 28 Septem360.6
1978)
3 June 1984 to
499.25
4 June 1984
23 September 1999 to
334.10
25 September 1999
It may be observed that though the drainage system of the city of Kolkata, as designed by William
Clarke, was based on a probable rainfall of a quarter inch (6 mm) of rainfall an hour, which is
equivalent to about 6 inches (150 mm) of rainfall in a day, there have been occasions when the
rainfall has exceeded this amount leading to serious congestion of the storm disposal system leading
to water logging in the city. There are further reasons also to contribute to increasing instances of
water logging condition in the city, and these have been discussed in the following paragraph.
3.13. Nature and problems of Kolkata's Drainage System
The city of Kolkata and its surrounding urban spaces are confronted with serious problems of
waterlogging as a result of cyclonic activities due to the following reasons.
At the time of high cyclonic activity over the region causes a huge accumulation of runoff water,
which has been increasing over the years due to paving of natural ground as a result of rapid
urbanisation. This water is drained, as mentioned before, through nearly 30km long channels to the
east of the city and discharged into the river Kultigang, which is connected to the Bay of Bengal
through the tidal creek of Raimangal. As such, at the outfall point of the water channels, the normal
tidal variation is such that a flow by gravity into Kultigang is only possible for only about 7 to 8 hours a
day. Naturally, at the time of a cyclone, the general water level of the tidal creeks rise due a rise of