Agreements & MOUs - The Ganga: Water Use in the Indian Subcontinent - page 205

million cubic metres, near Santipur and at Balagarh below Kalna between 1980 and
1987. The island in the river near Balagarh rose by more than five metres with the
dredged spoil. This place has since been selected for the site of a thermal power
station.
From 1997, the river's capacity in high and low water-levels deteriorated further,
as the cubic capacity reduced by 6% to 8% of the 1996 capacity, in the aftermath of
the Treaty.
It is seen in the above table that the upper tidal reach of the Hooghly from
Nabadweep to Triveni was silting up, leading to gradual rise of the river-bed over
that in pre-barrage days. The navigable depth also gradually diminished. The upland
discharge from Farakka did not improve this reach.
The table also shows the effect of upland discharge on the fourth and fifth
reaches, i.e., the lower tidal reach and the upper estuary of the Hooghly-Triveni
to the Hooghly Point in terms of cubic capacity variation at mean-tide level (MTL),
which determines navigation depths over bars in lean season, the frequency of bores
round the year and salinity variation in the lean season. Table 10.12 below shows that
the upland discharge from Farakka had some positive effects on the reach between
Triveni and Kashipur, upstream of Calcutta Port area up to 1977 when 40,000 cusecs
were diverted into the river.
From 1978 water was diverted in the lean season as per the agreement and no
improvement was noticed. In fact, the cubic capacity started falling since and contin-
ued up to 1996. From 1997, the capacity fell further since the last available records
up to 1999. Thus, the limited upland flow could not improve this reach of the river.
No dredging has so far been done in this reach but extensive dredging with spoil

Table 10.12 Cubic capacity variation in the river Hooghly between Triveni and Hooghly point in
post-monsoon period at Mean Tide Level (MTL)

Triveni to Cossipore
(Calcutta port area) Cossipore to Hooghly point

Percentage
variation w.r.t.
1975 (+)/(-)

Percentage
variation w.r.t.
1975 (+)/(-)

Cubic capacity
(10 6 m 3 )

Cubic capacity
(10 6 m 3 ) Year Remarks

1 2 3 4 5 6

1975 152.0 - 498.0 - Before Agreement

1976 152.0 Nil 515.0 (-)3.43

1977 154.0 (-)1.32 521.0 (+)4.62

1982 152.0 Nil 526.0 (+)5.62 After Agreement

1987 151.0 (-)0.70 545.0 (+)9.44

1992 148.0 (-)2.63 533.0 (+)7.03 No Agreement

1996 150.0 (-)1.32 533.0 (+)7.03

1997 148.0 (-)2.63 540.0 (+)8.43 After Treaty

1998 145.0 (-)4.61 558.0 (+)12.05

1999 144.0 (-)5.26 543.0 (+)9.04