Concise Mahavamsa Ruwan Rajapakse, P.E., Sinhalanet.com 1

Concise Mahavamsa Ruwan Rajapakse, P.E., Sinhalanet.com 62
These rise to a ponderous wall immediately above the vents which regulated the escape of
the water, and each layer of the work is kept in its place by the frequent insertion, endwise
of long plinths of stone, whose extremities project beyond the surface”
Sir Emesrson Tennent (Ref: R.L Brohier, Ancient Irrigation Works of Ceylon)
Padawiya Inscription:
Inscription was found in Padawiya reservoir indicating it to be restored by King Parakramabahu at
later times.
Wahalkada Reservoir:
Another large reservoir built by King Mahasen. Mora Oya was dammed and a canal known as Yoda
Ela was built to bring water to this reservoir. The bund of this reservoir ranges from 50 to 60 ft in
height.
Mahadaragala Reservoir: (Nachchaduwa Reservoir):
Mahadaragala reservoir (today known as Nachchaduwa reservoir) is considered to be one of the
sixteen large reservoirs built by King Mahasen. Mahadaragala lies just outside the city of
Anuradhapura. Centuries later King Dhatusena built a canal (Jayaganga) to bring water to this
reservoir from Kalawewa. This reservoir is considered to be a bold scheme since huge flood water
with very high velocity could come down the valley. Mahavamsa probably makes another reference
to this reservoir during the time of King Moggallana II. It is said that King Moggallana II, who lived
300 years later built Passapatanavapi reservoir by damming the Kadamba river (Malwathu Oya). This
description matches well with Nachchaduwa. It is possible that Moggallana II could have expanded
the work of Mahasen.
The embankment is 5,550 ft long, 36 ft high with a slope of 2.5 ft horizontal to 1 vertical. The slope
facing the water is armed with stones. The reservoir has a capacity of 525 million Cu. ft and a surface
area of 2,015 acres.
167 feet long and 44 feet wide masonry structure was provided for flood escape. (Overflow weir or
Pitawana in Sinhalese).
“It was a bold scheme as floods estimated to amount to 11,000 cu ft per second were to be
expected and there was no suitable rock over which they could be allowed to flow, but it was
carried out successfully”
(Ref: H. Parker, Ancient Ceylon)
Minneriya Reservoir: (Manihira in Mahavamsa):
This is the crowning glory of King Mahasen. Minneriya reservoir is 21 miles in circumference. The
bund is built solidly as other works of King Mahasen has a height of 50 ft. The reservoir submerges
4,670 acres and has a capacity of 70,730 acre ft.