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KATHMANDU METROPOLIS:
Water Supply Problem By Dr. AB Thapa It is heartening to
know that the Kathmandu Metropolis Authority is
holding debates on water and electricity supply
problems in the valley. Needless to say
that the electricity sector in Nepal is
in a big mess, and, as a result,
the domestic consumers are now forced to
pay electricity bill at a rate of more
than Rs 9 per unit electricity supplied to
them. The present electricity tariff in Nepal
might be among the highest in our region.
Let us take the case of British Columbia
in Canada, a region, like Nepal, equally
rich in hydropower potential. Just few years
back the domestic consumers in British Columbia
were paying merely at a rate of about US
Cents 3 (three) per unit electricity consumed.
Very soon another great injustice is going
to be meted out to the inhabitants of
the Kathmandu valley. After the completion of
the Melamchi Project each inhabitant in
the valley would be forced pay every
month disproportionately big amount of money by
comparison to their monthly income to
cover water supply bills, despite the fact that
such price rise could be completely avoided.
It is hoped that the Kathmandu Metropolis
Authority would do its best to protect
the interest of the Kathmandu valley residents.
Metropolis Authority could organize debates on
electricity and water supply problems. Government
agencies, various INGOs and NGOs should be
invited to present their view on
the proposed Melamchi Project. It is explained
hereinafter how it could be possible
to provide Melamchi water for free and
electricity at a rate perhaps the lowest
in our region. Langtang River
Potential According to the Gandak
Basin Master Plan study carried under the UNDP
assistance, a fairly large storage reservoir can be
provided in the uppermost reach of the Langtang
River and thus the hydropower development
potential of this river is quite high.
. The Langtang storage reservoir can
help to provide all through the year
an uniform flow of about 15
cumecs in the middle and lower reaches
if this river is developed in combination
with the Melamchi Project.. There would be
a total head of about 2500
meters between the full supply
level of the Langtang storage
reservoir and the Melamchi powerhouse tailrace
that would be discharging the Melamchi
and the Langtang waters into the Kathmandu
valley. Such an enormous head could be
utilized for power generation by 3
hydropower stations to be built in a
cascade and out of them two power
stations would be operating at an
exceptionally high head of about 1000 meters
or more. The surplus Langtang and
Melamchi waters after the use in Kathmandu
valley could be easily delivered into the
existing Kulekhani storage reservoir and,
as a result, it would be
possible to run in full capacity
the Kulekhani No-1 & No-2 hydropower stations
by almost tripling their present annual
power generation capacity. The Langtang Power
Projects The Langtang projects
operating at a head of about
one thousand meters and more
could produce electric energy at a very
low cost . Apart from it, water in abundant
quantity could be supplied to the
Kathmandu valley for free. The concept of the
Langtang project solely for power generation
was developed under the UNDP supported
Gandak Basin Master Plan study . However, this
concept required some revision to
incorporate the drinking water supply component
to provide water to Kathmandu valley. It necessitated
that at the end the regulated
Langtang water after power generation
be discharged into the Melamchi river
instead of the Bhotekosi (Trisuli). According to the Gandak
Basin Master Plan a 120 m high dam has
been proposed on the Langtang Khola near
Jaithang. The volume of the reservoir would
be about 180 million cubic meters. Based
on revised concept the water in the
reservoir at a full supply level of 3995 meters
would be first tapped by the
Langtang-1 power station operating at a gross
head of 950 meters. The installed capacity of
this Langtang-1 power station located
near Ghore Tabela about 15 km downstream
from the storage reservoir would be about 70
MW. Water from the
Langtang-1 power station would be directly drawn
into the Langtang-2 power station. For
augmenting this flow the water
from the catchment downstream of the storage
dam would also be drawn into the
headrace tunnel of the Langtang-2 power station.
The installed capacity of the Langtang-2
power station operating at a head of
about 1300 meters would be about 150 MW. Why Langtang
Power Would Be Cheap Of all the site
characteristics, head is the most important.
Design guidelines, 1989 approved by the American
Society of Civil Engineers has given some
simple reasoning that would help to explain
why the super high head Langtang
power stations operating at many times greater
head by comparison with other hydropower
stations could be built at very low cost.
"Very simply if one doubles the head the
quantity of water needed to produce a certain
amount of energy is halved, Thus, for like site
energy development the penstock area and reservoir
volume are halved and further large cost
reductions occur for powerhouse and machinery costs.
This fundamental consideration is at the
root of the large cost reductions that
occur at higher heads." A joint team of German,
Japanese and US consultants has made an
interesting reference to a Canadian high
head project vis-à-vis the Upper Arun
project to be operated at moderately high head.
"It is worth mentioning that the search of the
worldwide inventory of the existing hydropower
installations identified only one plant with a
combined head and flow magnitudes greater
than that of the Upper Arun - Kemano in British
Columbia, Canada". At present the electricity generated
by the 896 MW Kemano Project with a 16.3 km long
headrace tunnel operating at 800 m head
provides power for Alcan's aluminum smelters
at Kitimat at a cost below US cents 3
per KWh. Urgent Need to
Review Melamchi Project At present people placed
at decision making level including politicians, businessmen
and all those who like to identify
themselves to be knowledgeable in the field
of water resources are never tired
of praising that the Melamchi water
supply project is a blessing to Kathmandu
people. Inhabitants of the Kathmandu valley
do not yet know that each of
them would have to pay from their wallet
a monthly water charge bill of
about four thousand rupees at present
price level soon after the Melamchi project
becomes ready unless the Government decides
to open its coffer to pay such bill
in the form subsidy. The planners of
the Melamchi project have completely overlooked
the paying capacity of the vast majority
of the Kathmandu people surviving on
very small income. There is an urgent
need to review the Melamchi project to
spare the Kathmandu people the terrible ordeal
of going through the pain of ruinous financial
burden. Fortunately, the Langtang
projects can help to avert this situation
of tragic financial crisis as explained below.
Very recently the hydropower component was dropped
from the Melamchi project. It is essential
that the hydro power component of
the Melamchi tunnel be again introduced. Melamchi Tunnel
Hydropower There exists a big
potential to generate cheap
electricity by using the diverted flow of
the Melamchi River The elevation of the
Melamchi intake weir is 1715 m and the inlet to
the treatment works near Sundarijal is
1409 m. Thus there is an enormously
big gross head of 306 m. The UNDP report
of the Melamchi Water Supply Project has
clearly stated that the net increment in
investment ( the cost of the powerhouse located
near Sundarijal with electromechanical equipment)
needed to implement the hydropower element is
relatively small as the intake headrace tunnel
and penstock are already in place for
conveying water to the treatment works. According
to the feasibility report of the Arun-3 Project operating
at a head of about 300 meters ( same as
the Melamchi Hydropower ) the cost of
electromechanical equipments and power station civil
works is only about 30% of the
total project cost. The UNDP study has
concluded that it would be worth constructing
the hydropower and it could make a
contribution to reducing the cost of drinking
water to Kathmandu. Despite such
conclusion, the hydro power component has
very recently been dropped from the
Melamchi project. The hydro power component
should again be reintroduced if the savings
on Melamchi power costs after the
diversion of the Melamchi and Langtang water is
to be utilized to subsidize the Kathmandu
valley water supply. Power To Subsidize
Water Supply The way the Melamchi project has been
planned clearly shows that the planners of this project were
unfamiliar with the water resources potential of the Melamchi river. A Melamchi
project conceived primarily as a power project linked with the existing Kulekhani
hydropowers acutely suffering from water shortages and also with the
Langtang projects could provide Kathmandu people water almost for
free A Melamchi project exclusively for water supply is obviously very expensive. The
project involves the construction of a 28 km long delivery tunnel. Thus, the
Melamchi tunnel is too long. Apart from it, the
tunnel size adopted based on the construction requirement is also very big for a scanty
dry season flow of only about 1.5 cumec. The proposed tunnel could be used as a transit
route for the passage of surplus Melamchi and
Langtang waters into the Kulekhani storage reservoir acutely suffering
from water shortage. After the Langtang
diversion the Melamchi tunnel could be expected
to run in full capacity of about
15 cumecs throughout the year. It would permit
a 35 MW Melamchi tunnel hydropower operating
at a head of about 300 meters to generate
annually about 300 GWh firm energy, which is
50% more than the generation
of the both Kulekhani No-1 and No-2
hydropower stations put together. New Ideas Should
be Explored There is no denying
the fact that countries all over world
are at present engaged in fierce fights not
in the battle field but in economic front
and trying their utmost to find new
ways to gain ground against their competitors.
For this purpose even developing countries
like ours are providing all out
support to encourage and promote new research
works in very complicated areas of
science and technology with the aim
to apply the findings in bolstering
economic growth and development. Unfortunately in
case of our country it surprises
and at the same time saddens everybody
when the concerned government agencies and the
institutions like the National Planning Commission
entrusted to coordinate the development activities
keeping abreast of all the latest developments
in science and technology turn deaf ears
to gross technical irregularities pointed out
by somebody else for free, despite the
fact that at stake is the fate of
very important works like the Melamchi and
Langtang projects directly linked to the
welfare of all the inhabitants of the
Kathmandu valley... In Conclusion The possibility of
developing the Langtang project and the
Melamchi project in combination for the
generation of exceptionally cheap electricity
on a scale sufficient to meet our
country's requirement for quite some time and
also to supply drinking water to
Kathmandu
valley for free should not
remain a mystery to the
institutions like the National Planning Commission,
the ICIMOD and other INGOs. It hardly needs
explanation that the works of the
institutions like the ICIMOD and other
INGOs would have been far more
significant to poor countries like Nepal if
those institutions could rise above day to day
office works to act as a think tank
to reach out to our planning institutions
in sorting out some of the critical
technological problems faced by us. They
could also help to develop awareness
of the true value of the natural resources
like the potential of the Langtang
river that could be effectively used to
accelerate the pace of socio-economic development
of Nepal. And finally, the inhabitants of
the Kathmandu valley would certainly be very
grateful if the Kathmandu Metropolis Authority
could provide forum to sort out the
current water supply problems. (Dr. Thapa writes on water resources)
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