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Will our large dams last forever?

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By Eng. Thushara Dissanayake

Today, dams are indispensable structures for human prosperity and play a considerable role in the world economy and Sri Lanka without exception. There are more than 59,000 large dams all over the world according to registered data of the International Commission on Large Dams (ICOLD). A dam is categorized as a large dam if the height of a dam is greater than 15 m. A dam of height 5 – 15 m is also considered a large dam if its storage capacity is more than 3 MCM. Accordingly, Sri Lanka has got around 94 large dams, 270 medium dams, and over 10,000 small dams. According to the ICOLD, China has the highest number of large dams numbering 23,841 while the USA and India rank second and third respectively. When dam type is concerned 65% of large dams are earthen dams and the main purpose of 47% of dams is to provide irrigation water.

Similar to many other man-made structures dams too have a finite lifetime. In technical terms, it is defined as the design lifetime, which is generally, 100 years. However, many dams may exist longer than the design lifetime while some may fail even a short time after the commissioning owing to design or construction faults and natural calamities as well. Many large dams in the world have been built during 1950-90 being an era of intensive dam construction. In Sri Lanka too, except Kaluganga and Moragahakanda dams, many of the other Mahaweli multi-purpose reservoirs were commissioned in the 1980s under the accelerated Mahaweli development programme. But the question is if the lifespan of a dam is 100 years how many of those dams will be left for us by the year 2100. The awful, though speculative, answer is nearly zero. Nevertheless, many dams will exist beyond their projected lifetime if we take care of them properly as discussed in detail below.

 

Source: Global Reservoir and Dam Database

 

Factors affecting the lifetime

The basic determinant factors of the lifetime of a dam are either the structural failure of the dam or siltation that makes it no more usable due to loss in active water holding capacity. However, dam failures are rare yet disastrous. There is a growing concern about the seismic safety of dams with the recent earth tremors that occurred around Victoria dam. However, according to the reports, the main cause of dam failure in the world is foundation problems while inadequate spillway capacity being the next. Although earthquakes cause huge damages to the manmade infrastructure, only less than one percent of dams have failed as consequences of earthquakes.

In the context of ongoing climate change, there will be more intensive rains that generate unprecedented inflows to reservoirs. Unless the reservoirs’ spillway capacities are adequate or augmented to cater to the future requirements of changed rainfall characteristics, there will be high chances of dam failures due to overtopping.

When a dam is no more usable due to either safety reasons or loss of capacity after excessive siltation it would have to be decommissioned. Sometimes the purpose of such decommissioning may be restoring the ecosystem or preventing harmful effects. In Sri Lanka, many small dams at the village level have been abandoned due to breaching or natural effects like insufficient rainfall or for reasons unknown. However, we are yet to experience a purposeful decommissioning of a dam. In contrast, nearly 800 dams have been removed in the US in the last 100 years.

The plight of major dams in Sri Lanka

Today, modern technology helps us to monitor the health of the dams properly. Some of the recent projects implemented by the government intended to assure the safety of the major dams by carrying out necessary improvements. Hence, it is unlikely that we will witness another dam failure disaster in our country like that of the Kantale dam in 1986, which is considered the biggest dam failure event in the recent past. Hence, it is not the safety of the dams that is critical now but their sustainability.

Many recently built major dams of the country that hold big water storage lie in the mountainous areas in the upcountry. Most of them will reach the end of the designed lifetime by the end of this century when the excessive soil erosion-led siltation is considered. As a rule of thumb, the reduction in the active capacity of a reservoir per annum is 1%. However, the rate will further escalate if the catchment areas of such tanks are prone to deforestation, which would result in more and more soil erosion. Eventually, the water holding capacities of the reservoirs will irrevocably decrease. For instance, the Rantambe dam has lost its capacity by 45% due to siltation during 34-year lifetime according to Prof. S.B. Weerakoon. The majority of these reservoirs are serving agricultural land by providing water for irrigation while some are multipurpose contributing to hydropower generation. The installed hydropower generation capacity of these dams is about 33% of the total power generation capacity of the country while the actual generation remains around 23%. The reduction in generation potential is mainly due to variation in rainfall and that would be further worsened as an impact of climate change.

In the meantime, many of our dams in the low country may experience fewer siltation issues. A recent bathymetric survey carried out by the Climate Resilience Improvement Project of the Ministry of Irrigation has revealed that capacity loss in the Nachchaduwa dam due to siltation is almost zero. Presumably, the reasons for less siltation are the flatter watershed consisting of ample forest cover with less soil erosion potential and the cascade minor tanks system in the watershed area that retains the silt transported with the rainfall-runoff. Hence, we can assume that many of our l

ow country dams are still maintaining their original capacities if similar conditions prevail as those of Nachchaduwa.

 

Present challenges

With these ongoing natural and manmade environmental changes, we cannot take all our dams for granted. If the total storage capacity of our dams is reduced, the potential for providing irrigation water, drinking water and generating hydropower will also go down. So, we have to pay attention to this imminent issues and challenges sooner than later. We will have to switch to alternatives ways of managing our water resources in order to sustain our irrigated agriculture. Further, a considerable portion of hydropower will have to be replaced with alternative sources preferably renewable energy.

There are only a few lucrative options left for us to manage the impending crisis; the option of reservoir desilting is not discussed here as it is a reactive measure, probably the last resort, which goes against the objective of this write-up.

Firstly, we have to protect the existing dams not only by doing structural renovations but also by conserving the whole watershed areas of them against deforestation and activities that increase soil erosion to minimize the capacity loss due to siltation. Secondly, we have to increase the water use efficiencies of our irrigated agriculture to the best possible level in line with the concept of more crop per drop. Thirdly, we have to switch to other renewable energy sources, which could compensate for the decreasing hydropower capacity in the future amidst the growing demand. The success of all these actions depends on the genuine understanding of the challenges ahead and prompt actions of all the stakeholders.

 

(Eng. Thushara Dissanayake is a Chartered Engineer specialising in water resources engineering with over 20 years of experience)



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Features

Sustaining good governance requires good systems

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A prominent feature of the first year of the NPP government is that it has not engaged in the institutional reforms which was expected of it. This observation comes in the context of the extraordinary mandate with which the government was elected and the high expectations that accompanied its rise to power. When in opposition and in its election manifesto, the JVP and NPP took a prominent role in advocating good governance systems for the country. They insisted on constitutional reform that included the abolition of the executive presidency and the concentration of power it epitomises, the strengthening of independent institutions that overlook key state institutions such as the judiciary, public service and police, and the reform or repeal of repressive laws such as the PTA and the Online Safety Act.

The transformation of a political party that averaged between three to five percent of the popular vote into one that currently forms the government with a two thirds majority in parliament is a testament to the faith that the general population placed in the JVP/ NPP combine. This faith was the outcome of more than three decades of disciplined conduct in the aftermath of the bitter experience of the 1988 to 1990 period of JVP insurrection. The manner in which the handful of JVP parliamentarians engaged in debate with well researched critiques of government policy and actions, and their service in times of disaster such as the tsunami of 2004 won them the trust of the people. This faith was bolstered by the Aragalaya movement which galvanized the citizens against the ruling elites of the past.

In this context, the long delay to repeal the Prevention of Terrorism Act which has earned notoriety for its abuse especially against ethnic and religious minorities, has been a disappointment to those who value human rights. So has been the delay in appointing an Auditor General, so important in ensuring accountability for the money expended by the state. The PTA has a long history of being used without restraint against those deemed to be anti-state which, ironically enough, included the JVP in the period 1988 to 1990. The draft Protection of the State from Terrorism Act (PSTA), published in December 2025, is the latest attempt to repeal and replace the PTA. Unfortunately, the PSTA largely replicates the structure, logic and dangers of previous failed counter terrorism bills, including the Counter Terrorism Act of 2018 and the Anti Terrorism Act proposed in 2023.

Misguided Assumption

Despite its stated commitment to rule of law and fundamental rights, the draft PTSA reproduces many of the core defects of the PTA. In a preliminary statement, the Centre for Policy Alternatives has observed among other things that “if there is a Detention Order made against the person, then in combination, the period of remand and detention can extend up to two years. This means that a person can languish in detention for up to two years without being charged with a crime. Such a long period again raises questions of the power of the State to target individuals, exacerbated by Sri Lanka’s history of long periods of remand and detention, which has contributed to abuse and violence.” Human Rights lawyer Ermiza Tegal has warned against the broad definition of terrorism under the proposed law: “The definition empowers state officials to term acts of dissent and civil disobedience as ‘terrorism’ and will lawfully permit disproportionate and excessive responses.”  The legitimate and peaceful protests against abuse of power by the authorities cannot be classified as acts of terror.

The willingness to retain such powers reflects the surmise that the government feels that keeping in place the structures that come from the past is to their benefit, as they can utilise those powers in a crisis. Due to the strict discipline that exists within the JVP/NPP at this time there may be an assumption that those the party appoints will not abuse their trust. However, the country’s experience with draconian laws designed for exceptional circumstances demonstrates that they tend to become tools of routine governance. On the plus side, the government has given two months for public comment which will become meaningful if the inputs from civil society actors are taken into consideration.

Worldwide experience has repeatedly demonstrated that integrity at the level of individual leaders, while necessary, is not sufficient to guarantee good governance over time. This is where the absence of institutional reform becomes significant. The aftermath of Cyclone Ditwah in particular has necessitated massive procurements of emergency relief which have to be disbursed at maximum speed. There are also significant amounts of foreign aid flowing into the country to help it deal with the relief and recovery phase. There are protocols in place that need to be followed and monitored so that a fiasco like the disappearance of tsunami aid in 2004 does not recur. To the government’s credit there are no such allegations at the present time. But precautions need to be in place, and those precautions depend less on trust in individuals than on the strength and independence of oversight institutions.

Inappropriate Appointments

It is in this context that the government’s efforts to appoint its own preferred nominees to the Auditor General’s Department has also come as a disappointment to civil society groups. The unsuitability of the latest presidential nominee has given rise to the surmise that this nomination was a time buying exercise to make an acting appointment. For the fourth time, the Constitutional Council refused to accept the president’s nominee. The term of the three independent civil society members of the Constitutional Council ends in January which would give the government the opportunity to appoint three new members of its choice and get its way in the future.

The failure to appoint a permanent Auditor General has created an institutional vacuum at a critical moment. The Auditor General acts as a watchdog, ensuring effective service delivery promoting integrity in public administration and providing an independent review of the performance and accountability. Transparency International has observed “The sequence of events following the retirement of the previous Auditor General points to a broader political inertia and a governance failure. Despite the clear constitutional importance of the role, the appointment process has remained protracted and opaque, raising serious questions about political will and commitment to accountability.”

It would appear that the government leadership takes the position they have been given the mandate to govern the country which requires implementation by those they have confidence in. This may explain their approach to the appointment (or non-appointment) at this time of the Auditor General. Yet this approach carries risks. Institutions are designed to function beyond the lifespan of any one government and to protect the public interest even when those in power are tempted to act otherwise. The challenge and opportunity for the NPP government is to safeguard independent institutions and enact just laws, so that the promise of system change endures beyond personalities and political cycles.

by Jehan Perera

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General education reforms: What about language and ethnicity?

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A new batch arrived at our Faculty again. Students representing almost all districts of the country remind me once again of the wonderful opportunity we have for promoting social and ethnic cohesion at our universities. Sadly, however, many students do not interact with each other during the first few semesters, not only because they do not speak each other’s language(s), but also because of the fear and distrust that still prevails among communities in our society.

General education reform presents an opportunity to explore ways to promote social and ethnic cohesion. A school curriculum could foster shared values, empathy, and critical thinking, through social studies and civics education, implement inclusive language policies, and raise critical awareness about our collective histories. Yet, the government’s new policy document, Transforming General Education in Sri Lanka 2025, leaves us little to look forward to in this regard.

The policy document points to several “salient” features within it, including: 1) a school credit system to quantify learning; 2) module-based formative and summative assessments to replace end-of-term tests; 3) skills assessment in Grade 9 consisting of a ‘literacy and numeracy test’ and a ‘career interest test’; 4) a comprehensive GPA-based reporting system spanning the various phases of education; 5) blended learning that combines online with classroom teaching; 6) learning units to guide students to select their preferred career pathways; 7) technology modules; 8) innovation labs; and 9) Early Childhood Education (ECE). Notably, social and ethnic cohesion does not appear in this list. Here, I explore how the proposed curriculum reforms align (or do not align) with the NPP’s pledge to inculcate “[s]afety, mutual understanding, trust and rights of all ethnicities and religious groups” (p.127), in their 2024 Election Manifesto.

Language/ethnicity in the present curriculum

The civil war ended over 15 years ago, but our general education system has done little to bring ethnic communities together. In fact, most students still cannot speak in the “second national language” (SNL) and textbooks continue to reinforce negative stereotyping of ethnic minorities, while leaving out crucial elements of our post-independence history.

Although SNL has been a compulsory subject since the 1990s, the hours dedicated to SNL are few, curricula poorly developed, and trained teachers few (Perera, 2025). Perhaps due to unconscious bias and for ideological reasons, SNL is not valued by parents and school communities more broadly. Most students, who enter our Faculty, only have basic reading/writing skills in SNL, apart from the few Muslim and Tamil students who schooled outside the North and the East; they pick up SNL by virtue of their environment, not the school curriculum.

Regardless of ethnic background, most undergraduates seem to be ignorant about crucial aspects of our country’s history of ethnic conflict. The Grade 11 history textbook, which contains the only chapter on the post-independence period, does not mention the civil war or the events that led up to it. While the textbook valourises ‘Sinhala Only’ as an anti-colonial policy (p.11), the material covering the period thereafter fails to mention the anti-Tamil riots, rise of rebel groups, escalation of civil war, and JVP insurrections. The words “Tamil” and “Muslim” appear most frequently in the chapter, ‘National Renaissance,’ which cursorily mentions “Sinhalese-Muslim riots” vis-à-vis the Temperance Movement (p.57). The disenfranchisement of the Malaiyaha Tamils and their history are completely left out.

Given the horrifying experiences of war and exclusion experienced by many of our peoples since independence, and because most students still learn in mono-ethnic schools having little interaction with the ‘Other’, it is not surprising that our undergraduates find it difficult to mix across language and ethnic communities. This environment also creates fertile ground for polarizing discourses that further divide and segregate students once they enter university.

More of the same?

How does Transforming General Education seek to address these problems? The introduction begins on a positive note: “The proposed reforms will create citizens with a critical consciousness who will respect and appreciate the diversity they see around them, along the lines of ethnicity, religion, gender, disability, and other areas of difference” (p.1). Although National Education Goal no. 8 somewhat problematically aims to “Develop a patriotic Sri Lankan citizen fostering national cohesion, national integrity, and national unity while respecting cultural diversity (p. 2), the curriculum reforms aim to embed values of “equity, inclusivity, and social justice” (p. 9) through education. Such buzzwords appear through the introduction, but are not reflected in the reforms.

Learning SNL is promoted under Language and Literacy (Learning Area no. 1) as “a critical means of reconciliation and co-existence”, but the number of hours assigned to SNL are minimal. For instance, at primary level (Grades 1 to 5), only 0.3 to 1 hour is allocated to SNL per week. Meanwhile, at junior secondary level (Grades 6 to 9), out of 35 credits (30 credits across 15 essential subjects that include SNL, history and civics; 3 credits of further learning modules; and 2 credits of transversal skills modules (p. 13, pp.18-19), SNL receives 1 credit (10 hours) per term. Like other essential subjects, SNL is to be assessed through formative and summative assessments within modules. As details of the Grade 9 skills assessment are not provided in the document, it is unclear whether SNL assessments will be included in the ‘Literacy and numeracy test’. At senior secondary level – phase 1 (Grades 10-11 – O/L equivalent), SNL is listed as an elective.

Refreshingly, the policy document does acknowledge the detrimental effects of funding cuts in the humanities and social sciences, and highlights their importance for creating knowledge that could help to “eradicate socioeconomic divisions and inequalities” (p.5-6). It goes on to point to the salience of the Humanities and Social Sciences Education under Learning Area no. 6 (p.12):

“Humanities and Social Sciences education is vital for students to develop as well as critique various forms of identities so that they have an awareness of their role in their immediate communities and nation. Such awareness will allow them to contribute towards the strengthening of democracy and intercommunal dialogue, which is necessary for peace and reconciliation. Furthermore, a strong grounding in the Humanities and Social Sciences will lead to equity and social justice concerning caste, disability, gender, and other features of social stratification.”

Sadly, the seemingly progressive philosophy guiding has not moulded the new curriculum. Subjects that could potentially address social/ethnic cohesion, such as environmental studies, history and civics, are not listed as learning areas at the primary level. History is allocated 20 hours (2 credits) across four years at junior secondary level (Grades 6 to 9), while only 10 hours (1 credit) are allocated to civics. Meanwhile, at the O/L, students will learn 5 compulsory subjects (Mother Tongue, English, Mathematics, Science, and Religion and Value Education), and 2 electives—SNL, history and civics are bunched together with the likes of entrepreneurship here. Unlike the compulsory subjects, which are allocated 140 hours (14 credits or 70 hours each) across two years, those who opt for history or civics as electives would only have 20 hours (2 credits) of learning in each. A further 14 credits per term are for further learning modules, which will allow students to explore their interests before committing to a A/L stream or career path.

With the distribution of credits across a large number of subjects, and the few credits available for SNL, history and civics, social/ethnic cohesion will likely remain on the back burner. It appears to be neglected at primary level, is dealt sparingly at junior secondary level, and relegated to electives in senior years. This means that students will be able to progress through their entire school years, like we did, with very basic competencies in SNL and little understanding of history.

Going forward

Whether the students who experience this curriculum will be able to “resist and respond to hegemonic, divisive forces that pose a threat to social harmony and multicultural coexistence” (p.9) as anticipated in the policy, is questionable. Education policymakers and others must call for more attention to social and ethnic cohesion in the curriculum. However, changes to the curriculum would only be meaningful if accompanied by constitutional reform, abolition of policies, such as the Prevention of Terrorism Act (and its proxies), and other political changes.

For now, our school system remains divided by ethnicity and religion. Research from conflict-ridden societies suggests that lack of intercultural exposure in mono-ethnic schools leads to ignorance, prejudice, and polarized positions on politics and national identity. While such problems must be addressed in broader education reform efforts that also safeguard minority identities, the new curriculum revision presents an opportune moment to move this agenda forward.

(Ramya Kumar is attached to the Department of Community and Family Medicine, Faculty of Medicine, University of Jaffna).

Kuppi is a politics and pedagogy happening on the margins of the lecture hall that parodies, subverts, and simultaneously reaffirms social hierarchies.

by Ramya Kumar

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Features

Top 10 Most Popular Festive Songs

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Certain songs become ever-present every December, and with Christmas just two days away, I thought of highlighting the Top 10 Most Popular Festive Songs.

The famous festive songs usually feature timeless classics like ‘White Christmas,’ ‘Silent Night,’ and ‘Jingle Bells,’ alongside modern staples like Mariah Carey’s ‘All I Want for Christmas Is You,’ Wham’s ‘Last Christmas,’ and Brenda Lee’s ‘Rockin’ Around the Christmas Tree.’

The following renowned Christmas songs are celebrated for their lasting impact and festive spirit:

*  ‘White Christmas’ — Bing Crosby

The most famous holiday song ever recorded, with estimated worldwide sales exceeding 50 million copies. It remains the best-selling single of all time.

*  ‘All I Want for Christmas Is You’ — Mariah Carey

A modern anthem that dominates global charts every December. As of late 2025, it holds an 18x Platinum certification in the US and is often ranked as the No. 1 popular holiday track.

Mariah Carey: ‘All I Want for Christmas Is You’

*  ‘Silent Night’ — Traditional

Widely considered the quintessential Christmas carol, it is valued for its peaceful melody and has been recorded by hundreds of artistes, most famously by Bing Crosby.

*  ‘Jingle Bells’ — Traditional

One of the most universally recognised and widely sung songs globally, making it a staple for children and festive gatherings.

*  ‘Rockin’ Around the Christmas Tree’ — Brenda Lee

Recorded when Lee was just 13, this rock ‘n’ roll favourite has seen a massive resurgence in the 2020s, often rivaling Mariah Carey for the top spot on the Billboard Hot 100.

*  ‘Last Christmas’ — Wham!

A bittersweet ’80s pop classic that has spent decades in the top 10 during the holiday season. It recently achieved 7x Platinum status in the UK.

*  ‘Jingle Bell Rock’ — Bobby Helms

A festive rockabilly standard released in 1957 that remains a staple of holiday radio and playlists.

*  ‘The Christmas Song (Chestnuts Roasting on an Open Fire)’— Nat King Cole

Known for its smooth, warm vocals, this track is frequently cited as the ultimate Christmas jazz standard.

Wham! ‘Last Christmas’

*  ‘It’s the Most Wonderful Time of the Year’ — Andy Williams

Released in 1963, this high-energy big band track is famous for capturing the “hectic merriment” of the season.

*  ‘Rudolph the Red-Nosed Reindeer’ — Gene Autry

A beloved narrative song that has sold approximately 25 million copies worldwide, cementing the character’s place in Christmas folklore.

Other perennial favourites often in the mix:

*  ‘Feliz Navidad’ – José Feliciano

*  ‘A Holly Jolly Christmas’ – Burl Ives

*  ‘Let It Snow! Let It Snow! Let It Snow!’ – Frank Sinatra

Let me also add that this Thursday’s ‘SceneAround’ feature (25th December) will be a Christmas edition, highlighting special Christmas and New Year messages put together by well-known personalities for readers of The Island.

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