Experts on dam safety are sounding an urgent
warning about the impact of increased human activity Ė including
tourism Ė on the countryís reservoirs, stressing that at least
one bund has been seriously damaged and many more may follow.
They also say that all of the countryís major
and minor dams need rehabilitation and that failure to act
immediately could result in catastrophe.
The issue was deemed crucial enough to
deserve mention in the latest Central Bank report. The last
major dam breach was in 1986, when damage to the Kantale bund
caused the deaths of 127 people. Around 8,000 families were
affected and vast stretches of property destroyed.
Sri Lanka has around 350 major dams and over
12,000 small dams serving irrigation, hydropower, urban domestic
water and flood mitigation purposes. An additional 10,000 to
15,000 minor dams have been abandoned and need restoration. In
charge of upkeep are the Mahaweli Authority, the irrigation
department and provincial councils, among others. All of them
find their resources drastically inadequate.
"The treasury gives us only one-fifth of our
annual requirement for dam maintenance," said an irrigation
department source. "We have been forced to prioritise some
projects and forget others. Problems have now accumulated over
the years. Our dams need major rehabilitation."
Several dams require extensive repairs. These
include the Parakrama Samudraya and the Giritale tank in
Polonnaruwa, and the Senanayake Samudraya in Ampara. "I can name
a few dams in every district that need fast attention," the
source lamented. "We will have to face the consequences in five
to ten years, at the most."
He explained that the sluice gate in Senanayake
Samudraya needs immediate repair but work cannot begin till
September as water levels are currently too high.
"There is a big rush by entrepreneurs to build
hotels and resorts close to water bodies and also to start water
sports," added D. W. R. Weerakoon, former director general of
irrigation. "We are even speaking of sea planes landing in
reservoirs which were originally designed to supply water for
irrigated agriculture or for domestic use. We canít impede
development but we must examine how to protect these structures
in the face of new activity."
"You canít just allow people to play around in
these reservoirs as they wish," he continued. "If someone is
interested in water sports, they must get permission subject to
a scientific analysis of how the new activity impacts on the
Authorities in Wellawaya confirmed that a
section of the Handapanagala bund has slipped into the water,
necessitating vital repairs. Irrigation officials are blaming
provincial tourism authorities. In April, the Uva Provincial
Council organised a New Year festival on the bund and also
arranged canoe races. While it provided much-needed
entertainment to the local populace, it also disturbed the
hydraulics of the dam.
"This bund was not in a good condition to begin
with," said another authoritative irrigation department
official. "The festival simply aggravated the problem. Even the
canoes, which donít have engines, had an effect. We have no
power to prevent influential people from doing these things."
The damages to the Handapanagala bund have
forced irrigation authorities to artificially lower the water
level of the reservoir. "We were compelled to do so," the
official said. "We usually preserve water for the next
cultivation cycle but we had no option at Handapanagala. The
farmers will suffer."
"When people start various activities within a
water body, it changes the hydro dynamics of the waterway,"
Weerakoon explained. "This has an effect on the main dam.
Anything can cause a disturbance, including inland fishing and
Encroachment is seen as a major problem.
Settlement in catchment areas has resulted in disturbance to
upstream hydrology. Downstream, too, populations have increased
causing interference in spillways, sluiceways and canals.
However, neither irrigation nor provincial authorities have
sufficient authority to deal with the dilemma.
Flood protection bunds have also been severely
encroached on. One example is the Kelani river flood protection
bund. "The Kelani river has two flood protection embankments,
one on its left bank protecting the Colombo city and one on the
right bank protecting the Kelaniya area and Gampaha district,"
Weerakoon pointed out. "These bunds have been very badly
encroached. Settlers have constructed shanties and dwellings,
sometimes cutting the earth bank to erect houses." The
irrigation department once went to courts and obtained police
support to evacuate the illegal residents but has found it
impossible to prevent new encroachment.
The same is true of flood protection bunds on
the Nilawala river, Ginganga and Kaluganga.
Are the dams safe?
Meanwhile, the irrigation department is calling
for a reanalysis of the entire dam network to evaluate the
safety of these structures in the face of altering topographical
conditions. "Ideally, dam engineers must reanalyse conditions
every ten years," said the official earlier quoted. "We design
structures to suit certain conditions. These are constantly
changing. We must start a comprehensive study now."
"One problem is that employees in government
departments are preoccupied with other issues," he elaborated.
"The irrigation department is no different. If a minister wants
a circuit bungalow reserved, an employee will drop everything
else and attend to that."
Systematic research is requisite to determining
the extent of decay and ageing in Sri Lankaís dams. But even
this survey requires experts and they have become a rare breed.
The best have migrated, drawn away by greener pastures.
Replace lost expertise
"You canít prevent people from leaving the
country but you must replace them," Weerakoon stressed. "We need
training. Since foreign scholarships have dwindled, we must
spend some money from our national budget to train our staff.
Not only high-level engineers, but middle and low-level
Irrigation authorities reiterate that the
reservoirs often have large settlements downstream -- therefore,
itís imperative to ensure safety. The country has no modern
technology to monitor and detect dam failure. This is
particularly vital where earth dams are concerned.
"We still depend on timely inspections and
reporting by knowledgeable people but technology is more
advanced now," Weerakoon said. "We canít replace human
observation, reporting and analysis but the process could be
less laborious and tedious. A simple sensor can ensure 24-hour
monitoring. Sri Lanka doesnít have the technology yet."
Experts emphasise that a disaster arising from
damage to or failure of a dam is not unavoidable. "We are aware
of the shortfalls, thereís a possibility of disaster and we must
strengthen ourselves," Weerakoon maintained. "What is most
desirable is that we prevent major disasters from happening.
"We must take preventive action now `85 we must
stop further deterioration."