| Mahaweli
Development Programme
The Mahaweli Ganga Development Progrmme, the largest integrated
rural development multi-purpose programme ever undertaken in Sri
lanka, was based on water resources of Mahaweli and alied six river
basins. Main objectives Were to increse agricultureal production,Hydro-power
generation, employement opportunities, and ,settlement of landeless
poor and flood control.The programme originally planed for the implementation
over a 35-year period was brought to acceleration in 1979,with incoperation
of Mahaweli Authority.
Background
The Dry Zone forms seventy per cent. of the land area of Sri Lanka
Though it has an annual rainfall of 40 to 60 inches, the pattern
of rainfall is such that agriculture is not possible without irrigation.
The average apart, there are considerable variations in the amount
of rainfall from year to year. Although most of the rainfall normally
precipitates from mid-October to mid-January, it can be concentrated
in a few heavy downpours with long periods of drought in between.
Rains may come early in October or may get delayed as late as the
second half of December. It is in these circumstances that irrigation
has always played a major role in the economy of our country and
we have a tradition of irrigation commencing from the fifth Century
B.C.
The Dry Zone,
the cradle of our civilization, had in the Polonnaruwa period over
seventy major irrigation schemes, numbering over 12,000. Most of
these irrigation schemes have been restored in the last forty years
and work on the restoration of the rest of the schemes-major and
minor-is continuing. The Dry Zone however is still subject to the
vagaries of weather as the local runoff dependent on the variable
rainfall does not give an assured water supply.
The Dry Zone,
the cradle of our civilization, had in the Polonnaruwa period over
seventy major irrigation schemes and countless number of minor irrigation
schemes, numbering over twelve thousand. A major portion of these
irrigation schemes have been restored in the last forty years, and
work on the restoration of the balance irrigation schemes - major
and minor, is continuing. The Dry Zone however, is still subject
to the vagaries of the weather as the local runoff dependent on
the variable rainfall, does not give an assured water supply.
The
University History of Ceylon credits King Aggabodhi I (AD 571 -
604) with the construction of the Minipe dam and the canal which
was not more than 17 miles as originally laid out : Sena ll (AD
1153 - 887) later extended the canal to a total length of 47 miles.
The great Kings Parakrama Bahu l (AD 1153 - 1186) who according
the Culawamsa constructed or restored 165 dams, 3,910 canals, 163
major tanks and 2,376 minor tanks, is next mentioned in relation
to the Mahaweli Ganga.
During his reign
a dam was constructed across the Mahaweli at a point slightly upstream,
now known as Kalinga Nuwara, from the base of which Aciravati canal
took off flowing west and then northwards while the Gomati canal
flowed eastwards past Dimbulagala towards Maduru Oya.
It was R. L.
Brohier's view that King Mahasena was responsible for the origin
of this scheme and that it was later augmented by King Dhatusena
an Parakrama Bahu the Great. He concludes that when the Mahavamsa
referred Pabbatanta canal, it was in fact referring to the canal
that flowed eastwards from Kalinga Nuwara.
The Aciravati
canal is now known as the Kalinga - Yoda Ela.
A lesser known
earlier work is the diversion at Kandakadu, in the deltaic regions
of the Mahaweli, to feed the lands in the Allai area.
In
ancient times during the Anuradhapura and Polonnaruwa periods, with
the technology and resources then available considerable use was
made of the water resources of the Mahaweli and its tributaries
of irrigation.
Harnessing the Mahaweli River - in Ancient
Time
The ancients harnessed the resources of the Mahaweli at three points,
their most remarkable achievement being at Minipe, then a few miles
upstream of Dastota at Kalinga - Nuwara, and at Kandakadu near the
deltaic area. They also laid out the intricate Elahera canal system
with an anicut across the Amban Ganga, one of the major tributaries
of the Mahaweli.
The first attempt
at harnessing the Mahaweli could be credited to King Mahasena (AD
275 - 301) who is recorded to have dammed the Mahaweli and built
the Pabbatanta canal to irrigate the area around Dimbulagala.
Dhatusena who
proclaimed himself king in AD 463 and became famous as the builder
of the Kalawewa also constructed a dam across the Mahaweli and "
created fields which were permanently watered", according to
the ancient chronicle, Culavamsa. This is thought to be a reference
to the extension of the Pabbatanta scheme constructed earlier by
Mahasena, according to the University History of Ceylon.
Rock inscriptions
of the 1st century BC have also revered to a canal, which was taken
off the Mahaweli in its broad lower course to irrigate the swampy
Minwila. No trace however exists of a stone dam having been built
at this point. The method adopt 2,000 years ago to divert the river
is therefore a matter for speculation.
A massive attempt
to harness the Mahaweli was at Minipe. R. L. Brohier in ANCIENT
IRRIGARTION WORKS IN CEYLON states: " It is said that in the
reign of King Dasenkeliya (another name of King Dhatusena) there
lived on the slopes of the Dumbara mountains a tribe of Veddhas
at the time called Yakkos. The king invited them to help in building
a large channel and an anicut across the Mahaweli Ganga . . . this
giant work which excites the wonder of the modern engineer consists
of a scheme which turns the Mahaweli Ganga at a bend in the river
where a large body of water enters a narrow channel contiguous to
the bank partially closed by two rocks which intercept the water
on its return to the main stream. These rocks when united by masonry
become a dam raising the waters in the natural channel to a great
height."
The Elahera
canal on the Amban Ganga was constructed by king Vasabha about 65
A. D. and was later extended by king Mahasena in 475 A. D. to feed
Minipe and Kaudulla tanks built by him, and further extended in
the seventh Century A. D. to feed Giritale and Kantalai tanks. On
the Kalu Ganga a branch of amban Ganga, a diversion dam was built
at Hattota and used to irrigate lands immediately under it and to
take the excess water to Elahara. Further doun on the Amban Ganga,
there was a diversion dam at Angamedilla, built by king Upasena
in 368 A.D to feed Topawewa. This same canal was later enlarged
by king Parakrama Bahu in 1153 A.D to feed Parakrama Samudra, Topawewa
and Nikawewa reservoirs.
On the main
Mahawweli River, the Minipe anicut was constructed in about 459
A.D. by King Datusena and irrigated a considerable extent of land
on the Left Bank of Minipe on the main Mahaweli Ganga, were also
Kalinga Ela and the Gomathi Ela built in the first few centuries
A.D to irrigated large extents of land. The Elahera anicut and the
channel system up to Kantalai, the Angamedilla anicut and the Left
Bank Canal, have been restored and are functioning.
The question
of development of the water resources of the Mahaweli to benefit
the dry zone, has been raised from time to time in the State council
from 1931 and in the house of representative from 1948. The Irrigation
Department started the collection of data, and preliminary surveys
and investigations in the early 1950,s. the preliminary proposals
for the development of he Mahaweli Ganga was published by the irrigation
department in 1959. further studies were carried out in the period
of 1958 to 1961 by a join United States Operation Mission (as the
USAID was then known) the Irrigation Department Team and preliminary
proposals for the development of the Development of the Mahaweli
Ganga water resources were made in a report published in 1961.
The Mahaweli Ganga, Sri Lanka's main river, rises in the Hatton
plateau in the heart of the mountainous center of the island, 1200
m. (4,200 ft) above the sea level. It is joined at Ulapane by the
Kotmale Oya, it is most important tributary in the upper reaches,
which itself cuts loose from Hortan Plains, a table - top plateau
2134 m. (7000 ft) above sea level. The catchments of both rivers
benefit from the NE and SW monsoons and revive an annual rainfall
of 4,445 to 5,080 mm. (175 to 200 inches).
Draining more
than 16 percent of the island's total land area, the Mahaweli in
its 330 km. (206 mls) long, serpentine journey to the sea carries
some 7,900 million cu. metres (6,400,000 ac. ft) of water which
is more than 20 per cent of the total run of all the island's rivers.
To Sri Lankans
who have battled the elemental power of rivers from the 6th century
BC, the might of the Mahaweli was always a taunting challenge. Yet
the more enterprising Sinhala Kings of ancient Sri Lanka, heirs
to a remarkable tradition of irrigation engineering, left behind
evidence that they had the measure of the might of the Mahaweli
and had indeed come to grips with its main stem, at three separate
points.
Indeed, Sri
Lanka has a remarkable heritage of ancient irrigation works of truly
epic proportions which eloquently testify to the highly sophisticated
level of hydraulic engineering practiced by her early craftsmen.
Some of these works date back to the 3rd century BC. Most of them
are so advanced in design and execution that they have endured to
the present day with very little renovation.
Vision
The overall
MASL Vision is “Harnessed Rivers, well-managed basins moved
from agrarian to prosperous society and promoted economic development”
The vision of the transition MASL is“prosperous society and
healthy eco system in the Mahaweli region”
Mission
The primary
task of MASL has been and remains ”the improvement of human
life in the Mahaweli impacted areas”.
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