pieces of stones in a way in which it began from
the area where water is filled in the tank bund
and going under the tank bund or piercing it. A
slab of stone, connected to the sluice vertically,
was used to release water. Water was released by
moving it. These slabs were known as ‘Diyaketa
Pahana’. In the Wessagiri inscription there is
a reference as “ Sathar Riyanak Diyat Hindavu
Diya Keta Pahan’’. It means that a stone slab,
which was connected to a sluice to control water,
was of a four Riyans (a unit of measurement )in
height.
Bisokotuwa (sluice gate) - Bisokotuwa (sluice
gate) is also a one part of the sluice. It means the
rectangular space made of stones, from which
water flows out from the tank. When it is looked
from above, it looks like a square. There are
more than one sluice made in tanks with a high
bund. Its purpose is to take water out with least
pressure level after releasing water at different
pressure levels. The mud sluice is at the bottom
level of a tank bund. This structure called the
mud sluice was used to remove alluvial collected
after a rainy season.
To build a sluice and to utilize it, a scientific
knowledge is essential. Specially, what related to
it is the understanding of the behaviour of the
water well. That characteristic is known as the
‘clearness of water’. That is why it is important to
learn about sluices under the title of ‘the ancient
science of our country’.
Canals – Making anicuts across rivers, gathering
water and taking the gathered water to tanks
was a technicality, related to water management,
which prevailed in our country from ancient
time. There is a reference about an officer named
‘Adika’ in an inscription which belongs to the 2nd
century B.C. He was a one who engaged himself
in constructing canals.
Constructing Elahera Ela barricading the Amban
River, which was a tributary of the Mahaweli
River, was a huge canal built in ancient time.
Water was carried through this to the tanks such
as Minneriya, Giritale, Kawudulla and Kantale.
There was another canal built barricading the
Mahaveli River in Minipe area to carry water up
to Polonnaruwa.Another section related to the water management
in our country in ancient time was the ponds
dug and made for the use of monks who stayed
in temples and monasteries. Kuttam Pokuna,
Kumara Pokuna, Eth Pokuna and Nelum Pokuna
were examples for this.There used to be a technology in our country
from ancient time to keep the standard and
coolness of water in personal using. Specially,
there is brackish water in the dry zones such
as Anuradhapura. Therefore, it is natural for
someone to invent techniques to protect the due
standard of water. A major procedure is that
they followed a systematic method in digging
wells for drinking water. Large sized clay pots
were put into the well and covered the walls of
the well with them. These wells are known as
‘Uraketa Lin’. Such ‘Uraketa Lin’ (wells) have
been discovered in several places in the dry zone.Water Fountains in Sigiriya -The fountains
which can be seen in the Western park of Sigiriya
are one of the greatest creations. Four fountains
have been created on either side of the entrance-
avenues that stretch across the Western water
park, towards the Sigiriya rock. The reason
for creating four fountains was the need of
making a certain change in the water- stream
level which goes up out of them. The method
in which these fountains have been made is
simple as well as efficient. The basic theory
followed there is lifting water abruptly, which
pours down from an approximate height of 600
feet through a system of gutters to the flat land,
by using pressure. By fixing a splinter of stone
with round shaped holes in the place where the
pressure is created, the water is thrown up in a
beautiful way. The method that has been used to
change the height of the water stream due to the