Ian Morris, in “Why the
West Rules – For Now” predicts that South India is likely to face
serious water shortages by 2025. It is not too wrong to say the
shortage has already arrived in 2013 itself – starting with Tamil
Nadu. Three suggestions to improve availability of potable water in
India.
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| View of Bay of Bengal from Chennai |
[1] Make Bay of Bengal a
fresh water storage body:
The Bay of Bengal is the
largest bay in the world. This bay occupies an area of 2,172,000
KM². A number of large rivers – the Ganges, Brahmaputra,
Godavari, Mahanadi, Krishna and Kaveri flow into the Bay of Bengal.
It is estimated that the annual run from the rivers into the bay is
about 8,000 KM3. The average depth of the bay is 2.5 KM.
Then, the total volume of water is around 2172000 x 2.5 = 5,430,000
KM3. If there is no salt water incursion into the bay, it
would be the largest fresh water bay in the world as well.
A few studies have
revealed that a saline 'pump' near Sri Lanka adds saltiness to the
water by circulating waters from the Arabian Sea into the bay. If
the 'pump' is managed, then in due course, the bay will turn into a
natural fresh water resource.
As such, the salinity
peaks 50m below the surface. Even if 10m of the fresh water floating
on the bay surface is utilizable, 217200 KM3 of fresh
water would be available. It is the fresh water floating on the bay
that promotes the monsoons. Salinity in the bay should be carefully
measured and monitored to convert the bay into a pristine water
resource.
[2] Pipe river water from North to South:
Since there is very
sizable runoff into the bay, it would do no harm to distribute water
from the Ganges, Brahmaputra, Godavari, Mahanadi and Krishna to the
South. I doubt it is practical to “network” and “link” the
rivers in any fashion. The only practical approach may be to carry
water in closed pipe lines like the Veeranam line supplying 180
million litres of water daily to Chennai. The pumping lines could be
laid parallel to railway tracks for easy construction, networking and
maintenance.
Chennai Metrowater sells
per load of 10M3 of water at Rs. 670/- A load of divine
Ganges water drawn straight from Haridwar might fetch premium prices
in the south.
[3] Prevent Pollution:
This is easier said than done. Pollutants are often
let into water bodies, as there is no other drain into which it could be let into. An
extensive drainage system should be built so that the pollutants can
be streamed into it, processed and recycled. The drainage stream
ought not to be allowed to run into rivers, canals, bay or the
oceans.
The shortest river that
empties into the bay, is River Cooum – about 64 KM long with its
estuary near the Chennai harbour. Until 1960s, this was a fresh
water river. This river is now virtually used as a drain. No river should be used to drain wastes. The real test to check if pollution control measures
are working correctly is to find potable water in the Cooum.
References:
[1] 'Why the West Rules –
For Now', Ian Morris
