2 feb 2010 |
News: When water does not arrive
Due to the climate changes, the mega city of
Dhaka in Bangladesh is facing considerable challenges from innumerous
floods and violent precipitation.
In Dhaka, Bangladesh, 12 million people depend
on the municipal water-supply system. However, supply is irregular, and
for the Dhaka population this means periods entirely without access to
clean drinking water, as the water from the underground never reaches
the consumers. Such challenges will demand comprehensive restructuring
of parts of Dhaka’s water-supply system. Grontmij | Carl Bro is at the
head of a scheme aimed at securing clean drinking water for the
population.
”The fundamental issue is that the water never
reaches the citizens of Dhaka. The supply lines are leaking by up to 60
per cent. These pipes have been made of poor materials, and – at the
same time – the design of the supply network is resulting in
insufficient water pressure,” says senior consultant Jens Thøgersen who
is responsible for Grontmij | Carl Bro’s Bangladesh water projects.
Uncertainty about the groundwater level
Today,
85 per cent of the drinking water supplied to Dhaka is abstracted from
the groundwater. Currently, the groundwater is being depleted to such a
degree that, judged by the current consumption rate, it is uncertain
whether the groundwater table will ever meet the recharge rate. It is
feared that, judged by current abstraction levels, groundwater resources
will be depleted – never to be reestablished.
A 60 per cent replacement is required
”The
difficulties arising from the groundwater level and supply lines
constitute massive problems,” Jens Thøgersen explains. He is stationed
in Bangladesh for the duration of the project. ”Well over 85 per cent of
Dhaka’s drinking water derives from the underground below the city
itself, whereas only 15 per cent come from surface sources. The city’s
sewer system is in such bad repair that, inevitably, sewage water will
seep into the supply pipes when these are not under pressure. This is
why, for a 5-year period, Grontmij | Carl Bro will be projecting and
supervising the renovation of the comprehensive and widely branched
water-supply system. The plan is to replace 60 per cent of the
distribution system, in order that leakage be minimised and the pipes
brought under pressure”.
Jens Thøgersen concludes: ”Since many
of the pipes run below heavily trafficked streets, the project
represents a major challenge. But in Grontmij | Carl Bro we feel well
equipped for the task, since, previously, we have participated in the
preparation of a master plan for the Dhaka water supply.” In total, the
project comprises the replacement and establishment of 2600 km of water
pipe. In about five years’ time, 8 of Dhaka’s 12 million citizens will
once again be able to enjoy absolutely clean drinking water.