Agreements & MOUs - The Ganga: Water Use in the Indian Subcontinent - page 210

Fig. 10.12 Salinity level of Hooghly water at Palta
upland discharge, fluctuations in water-level owing to flow and ebb-tide and on the
condition of the governing bars. In olden days, the river up to Calcutta Port area was
navigable in the following periods.
(I) From June to October at high water springs by vessels up to 8.7 m (28.60 feet)
draught and at high water neaps by vessels up to 8 m (26 feet) draught.
(II) From October to June by vessels between 6.70 m (22 feet) and 8.20 m
(26.90 feet) draught.
Before the construction of the Barrage, this draught had fallen to even below
6 m in both monsoon and other months owing to siltation in the bed and governing
bars. Afterward, navigability improved and even 8-m draught vessels were coming
to the Port with minimum dredging of the channel. However, this situation did not
last long and navigability declined since 1997. Presently, it has become difficult
even for 7-m draught vessels to visit Calcutta Port in the lean season, in spite of
intensive dredging at vulnerable bars and crossing up to the Sagar Island. This is
mainly due to the effect of the 1996 Treaty, under the discharge has been fluctuating
from as low as 10,000-15,000 and 35,000 cusecs in the lean season. Gradual decline
of the navigational channel of the Bhagirathi-Hooghly was noticed from 1997 and
therefore, can be attributed to the fault-lines of the 1996 Treaty.
This is another reason for lesser number of ships coming to Calcutta Port. All
over the world, ships had changed enormously by the year of the Treaty. Low-
draught and small capacity diesel and electric-driven ships were being replaced
by electronically controlled, computer - aided ocean-going bulk-carriers of high
draughts. Light cargoes were being carried in containers of various sizes and brought
to riverine ports like Calcutta, obviating the need for low-draught vessels. Because
of limitation of draught and difficulty of manœuvring larger ships in the narrowing