Cyclone and Storm Surge - Iczmpwb.org

3.18
the Bhangar region through the Chowreswar canal. The different branches of the Lower Bagjola
canal are named as BB1, CC1, DD1, EE1,, EE2, and XX1.
The central drainage catchment of the city lies between Galiff Street on the north, the park Street to
the south and the region between the Hooghly on the west and the Circular canal / the Sealdah-
Ballygunje railway line on the east.
The South-Central or the suburban region extends from A J C Bose Road, Park Street and the
Topsia Road on the north, up to Ballygunje – Budgebudge Railway line on the south. A portion of the
discharge of the Ballygunje pumping station on the DWF and the SWF channels during monsoon
rains is also sometimes directed towards the river Hooghly.
The storm water of the Southern or the Tollygunge and Jadavpur drainage regions, is partially
through the Tolly nullah and partially through the Tollygunge – Panchannagram canal that outfalls
into the Suburban Head Cut.
The drainage of the Eastern, or the Maniktola region, is partially through the Dhapa Lock Pumping
station and partially through the Krishnapur canal.
The South-suburban area, or the Behala and Garden-Reach regions, drain into the river Hooghly
through the Chadial and Monikhali canals, which have sluices at their outlets.
3.12. Rainfall scenario in the city of Kolkata
The rainfall characteristics of the city of Kolkata vary from an average of 1610 mm at Alipore to 1510
mm at Dumdum. At times, the daily rainfall exceeds 300 mm. Some of the excessive rainfalls
recorded for the city are provided in the following table.
Table 3-5. Amount and duration of some exceptional rainfall over the city of Kolkata
Date Rainfall in mm Duration
30 September 1738 381 5 hours
14 August 1788 253 20 hours
20 June 1893 213 36 hours
19 September 1990 369 24 hours