The Hindu 04.01.2012
Water projects – the pride of Coimbatore
The linking of eight rivers through tunnels and storing the water in
seven reservoirs at various stages under PAP constitute an engineering
marvel of the Kongu region
A full Pilloor dam with the intake well, which supplies drinking water
to Coimbatore, in the foreground. (Right) Siruvani dam which is the main
source of drinking water to Coimbatore city. — Photos: K. Ananthan
At a time when Coimbatore Vizha highlights the rich natural resources
and biodiversity of Coimbatore, it is compelling to touch upon the
famous water supply and irrigation systems in this region.
The linking of eight rivers through nearly 30 km of
tunnels and storing the water in seven reservoirs at various stages
under the Parambikulam – Aliyar Project (PAP) constitute an engineering
marvel of the Kongu region.
The west flowing rivers in the Western Ghats that drain into the Arabian Sea form the PAP project.
The scheme takes care of the irrigation needs of nearly
four lakh acres in four zones of the ayacut and they get water once in
two years on a rotation basis.
Two-thirds of the beneficiary areas are in the new
Tirupur district (earlier part of Coimbatore district) and one-third in
the present Coimbatore district helping them retain their agrarian
identity.
In post-Independent India, the farmers mooted the scheme
for bringing in an irrigation scheme. The proposal made in 1958 started
taking shape in 1960 and the final stage i.e., the Lower Nirar was
completed in 1982.
Water sharing
The sharing of water from PAP is governed by an
inter-State river water sharing agreement signed in 1970 with
retrospective effect from 1958.
The agreement was that Tamil Nadu would get 30.5 tmcft (thousand million cubic feet) and Kerala 19.55 tmcft.
The total realisation at Thirumurthi Dam as on date
stands at 22 tmcft owing to rainfall deficiency, percolation and seepage
loss because of the damages suffered by the contour canal over a period
of time.
The State has recently announced a scheme for repair of the contour canal at a cost of Rs.184.5 crore.
The rivers linked are Nirar, Anaimalaiaru, Sholayar, Parambikulam, Thoonakadavu, Peruvaripallam, Aliyar and Palar.
Of them, the last two rivers are in the plains while the
rest are in the ghat section. Except Palar and Anaimalaiaru, there are
dams across almost all the rivers.
The water is taken to Thirumurthi reservoir through a
number of tunnels totally measuring 30 km while the contour canal from
Sircarpathy power house to Thirumurthi measuring 49.3 km alone has a 9
km tunnel.
As far as pending works in the PAP scheme as per the
inter-State agreement are concerned, Tamil Nadu is waiting for
construction of the Anaimalaiaru dam and has been demanding construction
of Niraru-Nallaru dam. Kerala has to complete the Idamalayar dam as per
the agreement.
One main requirement for industrial growth is power and Coimbatore is a beneficiary of two major power projects.
Pykara and Kundah are two hydro projects in this region that generate 833 MW jointly.
Coimbatore is the main load centre for these two projects.
According to an official, the main water source for
Pykara is Mukurthi and it is Upper Bhavani and nearby water sources for
the Kundah.
Kundah and Pykara projects have six power houses each.
The power generated from these two projects mostly caters to the morning
and evening peak hour demands.
The Pykara project took off in 1932, facilitating
industrial growth in Coimbatore. The Kundah project was inaugurated in
the 1960s, according to the official.
For any outsider, getting to learn about Coimbatore will
not exclude its landmark water supply projects, especially the Siruvani
scheme that began providing water to Coimbatore in 1920. The dam
construction began in 1977 and was completed in 1984.
Then began the drawal of 101 million litres of water a
day following an agreement with Kerala (the dam is located in that
State).
“The sweet Siruvani water” is what every brochure or
promotional article on Coimbatore will contain, when its distinct
features are being listed.
Decades ago, the perseverance of one of the architects
of Coimbatore – C.S. Rathinasabapathy Mudaliar – led to implementation
of the scheme.
Mudaliar led a team of experts and members of the
Coimbatore municipality deep into the breathtaking Siruvani forests and
identified the spot where a project could be implemented to provide
drinking water to the municipality.
Siruvani water now flows to the city just by gravity
over a distance of more than 30 km and this speaks volumes of how the
scheme was conceived in such a way that expenses on power consumption
for pumping the water could be avoided. The terrain too supported this
initiative.
The other landmark is the Pilloor scheme. If the
Siruvani project is all about Nature reaching out to the community
through the gradient, the Pilloor scheme, implemented in the early
nineties, is an engineering marvel.
Water from the Pilloor Dam reaches the city through a
tunnel dug through a mountain. The scheme supplemented the quantum
supplied from the Siruvani Dam.
Officials of the Tamil Nadu Water Supply and Drainage
Board say the Pilloor project had been implemented with a lot of
forethought. Provision for a second phase scheme had been made even when
the first one had been executed.
This is why the Corporation is able to lay an additional line through the tunnel now to implement the second phase.
