per cent, or 2.5 crore liters, of water
1960s. By this time, G.W. levels in the
stored in the Jamuniya Dam in Uttar
central London had fallen by about 65
Pradesh. The state stores its share in five
m. b.g.l. in 1845 to almost 100 m. b.g.l .
dams, including the Bari Ghat. As the
in 1967. In 1965, it is estimated that
drought this year has worsened, water in
about 480 ml/d were being withdrawn
the
four
other
–
dams
Harpura,
from the chalk of the London basin.
Charpuva, Madiya and Sudan dams –
Slowly this withdrawal declined steadily
has dried up.
to about 380 ml/d in early 1980s and
remain relatively stable until around
SPECIAL NEWS:Urban groundwater problem
(Continued from Newsletter from 50)
1990. As withdrawal from this layer
decreased further, G.W. levels in the
confined aquifers began to recover; rates
London:
Since 19th century London expanded
rapidly and the industrial, commercial
and public demand for water increased.
Groundwater
became
increasingly
important as a water source. The
geology of the central London shows
of G.W. level rise, reached upto 3 m. per
year in the center of the basin. In late
1980s the constituting G.W level rise
was recognized as a risk with potential
consequences of
a.
that
groundwater
initially
levels
had
that
artesian
became
prevalent. Progressive increases in water
subsurface
including
deep
tunnels and the basements of tall
clays of the Lambeth Group; for water
aquifer
of
infrastructure,
London clay and the silts, sands and
drilling into the confined Sand/Chalk
Flooding
buildings;
b.
Changes in geotechnical prospects
that could affect the deeply founded
structures such as tall building.
withdrawal from the confined Chalk in
Although there was a clear risk from
the late 19th century and early 20th
rising G.W. levels, there was little
century
support from Govt. to address the issue.
unsustainable,
eventually
resulting
became
in
steady
groundwater level decline till mid-
However,
stakeholders
in
1998
launched
some
a
of
the
5-phase
5
Integrated River Basin Management Society