Cyclone and Storm Surge - Iczmpwb.org

3.2
a storm surge caused by a tropical cyclone. Under such a condition, when a lot of water needs to be
discharged off from the city, the outfalls are found to be blocked of by a high water level of the
creeks. This renders the city waterlogged for many hours at a stretch at times. In order to understand
the full system of Kolkata’s urban drainage and the reason for this kind of drainage congestion, it is
necessary to go back in history and review the city’s drainage system from the beginning. The
authors of this project report are grateful to Dr. S. S. Ganguly, retired Superintending Engineer,
Irrigation and Waterways Department, Government of West Bengal for permitting the use of the
following descriptions about Kolkata and its drainage proposals from the paper Ganguly (2006).
3.2 Physiography and the drainage systems planned during the formative years of Calcutta
(Kolkata)
The physiographic setting of Kolkata (22° 34' N, 88° 22' E), both at the time of its foundation as well
as in the present day, is dominated by the meandering Hooghly river. Along the left bank of the river,
which is also the western boundary of the city, there stretches a narrow belt of comparatively high
natural levee, which varies in 2 to 5 kilometers. As a consequence of this natural levee general slope
of the land was from west to west. But during the initial years, drainage of the city was directed
westwards to the Hooghly-river. A small creek, the Gobindapur creek was utilized. The creek ran
from the Salt Lakes in the east via present day Beliaghata, Sealdah, Creek Row, Dharmatolla and
Government Place (North) before draining into the Hooghly below the Princep Ghat. This creek also
served as a navigation channel and it is reported that Charnock used to collect toll from the boats
moving in and out of the creek. But in course of a furious hurricane on Sept. 30, 1737 when 15
inches (38.10 cm) of rainfall occurred in just 5 hours, 20,000 ships, barks, sloops, boats, canoes etc.
were destroyed, the creek was rendered almost useless for navigation. In 1742, a seven mile long
ditch was excavated along the present alignment of the Circular Road (APC Road & JPC Road) to
keep the Maratha marauders at bay. This ditch aptly called the Marhatta ditch sounded the death
knell of the creek. The natural and man made interferences took their tool on the not so efficient
drainage system of the city. Very soon drainage congestion resulted and prolonged water logging
was the order of the day. The consequences were so severe for the health and hygiene of the city
that then Governor General Lord Wellesley (1766 - 1842) had to intervene. His now famous minutes
of June 16, 1803, which recommended radical change in the direction of the principal channel of the
Public Drains, read as follows:
"The defects of the climate of Calcutta, during the part of the rainy season, may indeed be ascribed
to the state of the drains and water courses and to the stagnated water remaining in the Town and its