Eng. D. L. O. Mendis: The Engineer Who Reimagined Our Nation and Profession
By Eng. Kidnapillai Selvarajah (Selva)
1.Introduction:
Eng. Devaradura Lucius Oswald Mendis (D.L.O. Mendis) was an influential figure in Sri Lankan engineering, articulating a vision that extended far beyond technical design, specifications, and infrastructure. In the 1950s, as the engineering profession in Ceylon began to transcend its British colonial origins, he recognized that engineering was inextricably linked to ecology, sustainability, and the evolution of human civilization. Throughout a distinguished career spanning seven decades, his work consistently advocated for a built environment that exists in equilibrium with natural ecological systems. I can state without hesitation that Eng. Mendis was a pioneer, arguably the first in Sri Lankan engineer to frame engineering as a discipline dedicated to the stewardship of both life and landscape.
Professional identity within the institutional framework, he was a prominent advocate for the intellectual independence of the Sri Lankan engineers. He challenged the profession to move beyond a "colonial executor" mindset, urging engineers to transition from mere implementers of external designs to ethical guardians of national planning. His advocacy was instrumental in elevating engineering to the status of a truly learned profession, one that balances technical competency with moral values and social context. Through this philosophy, he contributed to a paradigm shift, grounding the profession in social responsibility and cultural authenticity.
My introduction to Eng. Mendis occurred in August 1984 through his close colleague, Prof. A. Thurairajah, following a session of the IESL Training and Education Committee. Meeting in the corridors of the IESL, the profound mutual respect between these two men was immediately apparent. They were united by a shared intellectual spirit and a commitment to engineering as a humane and ethical vocation. This encounter initiated my long-standing appreciation for Eng. Mendis’s legacy not only as a visionary practitioner but as a steadfast champion for the profession’s higher purpose in society.
2.Education:
Eng. D. L. O. Mendis, affectionately known as 'LO' to his friends and colleagues, was a rare kind of engineer, and his intellectual foundations were shaped early in life. He began his schooling at Ladies’ College before moving to Royal College, Colombo, where his academic strengths and curiosity deepened. From there, he entered the Faculty of Engineering at the University of Ceylon, the country’s first home‑grown engineering faculty, joining the inaugural batch of engineering students in 1950, and graduating in 1955. As one of the very first entrants to this historic cohort around twenty-five students, Eng. Mendis probably held the first registration number simply because his name appeared first in alphabetical order.
Those formative years were pivotal. During his studies, he developed a close and enduring professional association with some of the towering figures of engineering education, particular reference to Prof. E. O. E. Pereira and Prof. R. H. Paul. Their mentorship not only shaped his technical grounding but also nurtured the broader philosophical and societal perspectives that would later define his unique contribution to the profession.
3.Early Engineering Career:
In the early years of his professional journey, Eng. Mendis entered the field of irrigation engineering with the quiet confidence of a young man who already understood the weight of public service. A product of the University of Ceylon, he served on the Kantalai and Allai schemes in the late 1950s and early 1960s, immersing himself in the practical realities of water management and rural development. These formative assignments placed him in direct contact with the landscape and its people, where he confronted the delicate balance between engineering precision, the ecological health of human habitats, and the livelihoods of farming communities. It was in these early field postings, observing the harmony of ancient irrigation systems that he began to cultivate the blend of analytical clarity, ecological sensitivity, and public-minded purpose that would later define his national contributions.
4.Critique: The Uda Walawe Reservoir Project:
The Uda Walawe Reservoir project, constructed in the late 1960s in southern Sri Lanka, is a major, multi-purpose infrastructure initiative designed for irrigation, hydroelectric power generation, and regional development. It features a large dam on the Walawe River, creating a reservoir that supplies water to the Right Bank (RBMC) and Left Bank (LBMC) canals to irrigate thousands of hectares of land. Eng. Mendis was widely recognized for his bold and uncompromising critique of the Uda Walawe reservoir project, which he viewed as a misguided, large-scale intervention that ignored Sri Lanka’s superior and sustainable ancient tank-cascade traditions. He argued that the project’s fundamental flaw lay in its very location: by building in the middle basin at approximately 290 ft MSL rather than further upstream, the design sacrificed nearly half of the potential irrigable area in the upper basin. He frequently highlighted this error by citing the work of Senior Irrigation Engineer M.S.M. de Silva, pointing out that the project disregarded the ancient "cascade system" of small tanks which had maintained an ecological balance for centuries.
5.Challenging the "Evaporating Pan" Mindset:
He criticized the prevailing colonial engineering mindset of the era, which favoured massive, centralized reservoirs that he disparagingly described as “evaporating pans.” He argued these systems were prone to high water loss and low efficiency compared to the decentralized, resilient systems perfected by ancient communities. He further contended that colonial-trained engineers and foreign engineering consultants, including those behind the 1979 Asian Development Bank (ADB) project assessments failed to appreciate the local wisdom and social capital of Sri Lankan farmers.(Note: ADB-supported irrigation projects in Sri Lanka around 1979, such as the Walawe Irrigation Improvement Project, faced significant challenges, including design deficiencies, cost overruns, and implementation delays due to civil disturbances. Assessments highlighted a need for better water management, with early projects like those in the 1970s suffering from poor infrastructure design). Eng. Mendis noted that a superior alternative site at Huratgamuva, proposed by local engineers, was dismissed in favour of what he considered a fundamentally flawed location. For Eng. Mendis, the subsequent realities of the project, poor water-use efficiency, design limitations like single-bank canals, and rapid siltation served as a definitive confirmation of his warnings. His lesson was clear: Sri Lanka’s future lay not in replicating large dams, but in rehabilitating the ancient small-tank cascades which offered a truly sustainable path forward.
6.The Accelerated Mahaweli Development Programme:
Eng. Mendis was perhaps the most formidable and consistent critic of the Accelerated Mahaweli Development Programme launched in 1977, by the J R Jayawardena led UNP government. At a time when the nation embraced the project as a singular symbol of rapid modernization, he warned that “accelerated” engineering often bypassed the slower, more deliberate ecological wisdom embedded in Sri Lanka’s ancient hydraulic civilization. Most importantly, the accelerated timeline significantly increased costs and reliance on foreign assistance.
He argued that the programme’s reliance on massive, centralized reservoirs and rigid concrete canals risked submerging both literally and intellectually the time-tested Small Tank Cascade Systems, which he regarded as the pinnacle of sustainable water management. To him, the Mahaweli scheme reflected a Western "hydraulic" mindset imposed on a landscape whose natural rhythms, micro-catchments, and community-based water cultures demanded a far more nuanced approach. His critique was never opposition for its own sake, but a profound call to recognize that true development must work with the grain of the land, rather than against it.
7.Golden Era: Ministry of Planning and Economic Affairs:
From 1970 to 1977, Eng. Mendis served in the influential “Super Ministry” of Planning and Economic Affairs under the United Front Government led by Prime Minister Sirimavo Bandaranaike, working under the administrative leadership of the distinguished Secretary, Prof. H. A. de S. Gunasekara. This period can be regarded as the golden era of Eng. Mendis’s public‑service career, during which he used his political insight and professional standing to elevate the standard and importance of the engineering profession within national policy circles.
In an environment where national planning, economic restructuring, and long‑term development strategy converged, he played a pivotal role in strengthening the strategic relevance of engineering in the public service. As a key technical advisor, he brought analytical depth, ecological awareness, and a systems‑thinking perspective to policy discussions often dominated by economists and administrators. He was among the rare officials with direct access to both Prime Minister Sirimavo Bandaranaike and Prof. Gunasekara, enabling him to influence decisions at the highest levels. His counsel was valued not only for technical expertise but for his ability to frame engineering as central to national development, environmental stewardship, and the ethical use of public resources. During these years, he helped shift the perception of engineers from mere implementers to essential contributors in shaping the country’s development philosophy.
8.Creation of the Ceylon Engineering Service:
The establishment of the Ceylon Engineering Service (CES) now the Sri Lanka Engineering Service (SLES) on October 1, 1971, marked a watershed moment in the professionalisation of engineering within the public sector. Eng. Mendis was one of the key catalysts behind this achievement, working alongside a distinguished group of visionaries such as Prof. E. O. E. Pereira, Prof R H Paul, Dr. Nath Amarakone, Dr. A. N. S. Kulasinghe, Eng. D. J. Wimalasurendra, and then IESL President Eng. P. H. Perera. Together, they recognised that the country’s development ambitions required a structured, respected, and intellectually empowered engineering cadre one capable of shaping national policy rather than merely implementing it. The CES was conceived not simply as an administrative reform, but as a declaration that engineering expertise was central to the nation’s economic planning, infrastructure development, and long‑term sustainability.
Eng. Mendis was among the most articulate champions of this transformation. He consistently argued that engineers should not remain mere ‘executors’ of plans drawn up by others but should become the ‘planners’ themselves professionals who could conceptualise, design, evaluate, and guide national development with technical insight and ethical responsibility. He famously maintained that a “contented engineering service” was essential to halting the growing brain drain of the 1960s and 1970s, which saw many of the country’s brightest engineers leaving for opportunities abroad.
For him, the CES was not only a structural necessity but a moral imperative: a way to retain talent, elevate professional dignity, and ensure the success of the United Front Government’s Five‑Year Plan. Drawing on his influence within both the Ministry of Planning and Economic Affairs and the Institution of Engineers, Sri Lanka (IESL), he played a decisive role in shaping the CES into a robust state service that recognised engineering as a cornerstone of national development.
9.Architect: Founding the NERDC:
Eng. Mendis was the primary architect behind the establishment of the National Engineering Research and Development Centre (NERDC) of Sri Lanka. In 1974, while serving as the Ministry of Planning’s representative to the Industrial Development Board (IDB), he was entrusted by Mr. Hector Abayawardana with a task of national significance: to conceptualise an institution capable of bridging the long‑standing gap between industrial extension services and pure scientific research. At a time when Sri Lanka urgently needed a homegrown technological capability, he recognised that the country required not just laboratories, but a coordinated national engine for innovation.
Drawing on his deep understanding of national planning and his ability to translate policy into institutional architecture, Eng. Mendis personally drafted the landmark Cabinet Paper that laid the foundation for NERDC. His proposal secured the endorsement of the Minister of Industries and Scientific Affairs, T. B. Subasinghe, reflecting both the strength of his vision and the trust placed in his judgement. The culmination of this work came on 14 August 1974, when NERDC was formally gazetted establishing a unique mechanism dedicated to the advancement of indigenous technology, appropriate engineering solutions, and the long‑term strengthening of Sri Lanka’s industrial capability.
In shaping NERDC, Eng. Mendis did far more than create an institution; he carved out a national pathway for engineering research, innovation, and self‑reliance. His work ensured that Sri Lanka’s engineers would have a dedicated platform to develop technologies rooted in local needs, local materials, and local ingenuity.
10. The ‘River for Jaffna’: Unifying National Dream
Perhaps no project better illuminates Eng. Mendis’s devotion to a united Sri Lanka than his tireless advocacy for the ‘River for Jaffna.’ Building upon the original 1950s concept by legendary engineer Sanmugam Arumugam, he elevated the proposal from a technical water‑management scheme into a transformative national vision. Where others saw a hydraulic intervention, he saw a pathway to ecological renewal, agricultural revival, and social reconciliation.
He understood that converting the Elephant Pass and Uppu Aru lagoons into freshwater lakes was not simply a matter of desalination. To him, it represented a profound act of ecological restoration—a way to replenish the Jaffna peninsula’s depleted groundwater, restore its once‑thriving agricultural base, and revive the livelihoods that had sustained its people for generations. In his eyes, water was not just a resource; it was a bridge between communities, a healer of landscapes, and a symbol of shared belonging.
Even during the darkest years of the ethnic conflict, when the idea of national unity felt remote, Eng. Mendis remained the project’s most steadfast and honest champion. He presented meticulously researched technical papers at the Institution of Engineers, Sri Lanka (IESL) and at international forums, demonstrating not only the feasibility of the scheme but its long‑term economic and ecological benefits. His advocacy was courageous, consistent, and rooted in a deep conviction that engineering must serve humanity, not merely infrastructure.
Although the full vision of the ‘River for Jaffna’ is yet to be realised, Eng. Mendis’s persistent campaigning ensured that this quiet revolution never disappeared from the national imagination. His work stands as a testament to his belief that engineering—when guided by nature’s own logic and aligned with the moral imperative of unity—can become one of the most powerful instruments for peace, dignity, and prosperity in Mother Lanka.
11. Tribute from Eng S Arumugam:
The originator of the visionary ‘River for Jaffna’ concept, Eng. S. Arumugam, paid a heartfelt tribute to Eng. Mendis in his autobiography Times of Our Life (pp. 234–235), where he acknowledged Mendis’s unwavering commitment to advancing the project.
"D L O Mendis, a former President of the Institution of Engineers, Sri Lanka, and Adviser to the Ministry of Planning and Economic Affairs, is a self-confessed academic disciple of Arumugam, and wrote in one of his books that: "This author has repeatedly paid tribute to S Arumugam, now a nonagenarian living in London, as the foremost engineer in his time who recognised the true significance and value of the ancient small tank systems. He was thus implicitly opposed to the conventional wisdom of the hydraulic engineers who dominated the scene in the Irrigation Department and led the Irrigation Ministry to follow them. This conventional wisdom maintained that the small tanks were "inefficient" and had to be replaced by large reservoirs and channel systems. Sadly, the hydraulic engineers had their way."
Eng. Mendis actively championed the implementation of the project through multiple national platforms. At the Institution of Engineers, Sri Lanka, he moved and secured a formal resolution urging the Government to proceed with the scheme.
Within the Sri Lanka Pugwash Group, he organised a well‑attended public seminar to broaden scientific and civic understanding of the proposal. He also ensured that the project received wide publicity in the media, consistently drawing public attention to its national importance.
12.Pugwash Group: Engineering Peace Beyond Blueprints:
Beyond the technical borders of his profession, Eng. Mendis emerged as a founding pillar of the Sri Lanka Pugwash Group, the national chapter of the Nobel Peace Prize‑winning international movement dedicated to reducing global conflict through science and dialogue. Within this circle of distinguished thinkers including Prof. C. R. Panabokke, Prof. Valentine Joseph, Eng. Ray Wijewardene, Dr. S. Gnanalingam, Diplomat Jayantha Dhanapala, and Eng. (Dr.) K. Tharmaratnam, he was both a steady voice of reason and a moral compass.
He worked tirelessly to uphold the ‘Pugwash spirit’: the conviction that professionals, especially scientists and engineers, bear a moral responsibility to advocate for peace. In a country deeply scarred by civil strife, he championed the idea that engineering solutions—such as the equitable distribution of water, energy, and essential resources—were not merely technical interventions but foundational tools for justice, reconciliation, and national harmony.
Through his leadership in the Sri Lanka Pugwash Group, Eng. Mendis helped create a rare, neutral space where ideas could be exchanged without fear or political distortion. His presence reminded all who gathered that the true calling of an engineer extends far beyond the construction of physical structures. It is, at its highest level, the construction of trust, stability, and the very architecture of a peaceful society.
13. Hydraulic Heritage and the Rights of Future Generations:
A defining hallmark of Eng. Mendis’s legacy was his unwavering defence of Sri Lanka’s ancient hydraulic civilisation. He regarded the village tank cascades (ellanga) and community‑based irrigation systems not as nostalgic remnants of a bygone era, but as highly sophisticated, ecologically attuned water‑management networks—systems that modern engineering was only beginning to appreciate. To him, these cascades represented a uniquely Sri Lankan synthesis of hydrology, ecology, agriculture, and community governance. They were living proof that sustainable engineering had deep roots in the island’s history.
This profound respect for Indigenous hydraulic wisdom shaped his courageous involvement in the Eppawala Phosphate controversy of the late 1990s. When a proposed multinational mining project—backed by large foreign interests—threatened to devastate the North Central Province’s fragile tank‑cascade ecosystems, displace long‑settled farming communities, and compromise the region’s groundwater, Eng. Mendis emerged as one of the most authoritative voices of resistance. He recognised that the proposed open‑pit mine would not only extract a finite mineral deposit but would irreversibly damage an entire cultural landscape built on centuries of sustainable agriculture.
Eng. Mendis provided both the technical credibility and the ethical backbone for the opposition movement. He argued forcefully that the true wealth of Eppawala lay not in a short‑term mineral windfall, but in the enduring agricultural heritage sustained by its tank systems, its soil fertility, and its intergenerational knowledge. His analyses and public interventions helped frame the issue not merely as an environmental dispute, but as a question of national sovereignty, ecological stewardship, and the rights of future generations.
14 Supreme Court Case:
His contributions became pivotal in the landmark Supreme Court case Bulankulama v. Secretary, Ministry of Industrial Development (two thousand), often referred to as the “Eppawala Case.” In this historic judgment, the Court invoked and strengthened the Public Trust Doctrine, affirming that the State holds natural resources in trust for the people and cannot alienate them for narrow commercial gain. The ruling established that the gifts of nature—land, water, minerals, forests—belong not only to the present generation but to all who will inherit the island.
15. Devotion: Institution of Engineers, Sri Lanka:
The professional life of Eng Mendis was inextricably intertwined and devoted with the Institution of Engineers, Sri Lanka (IESL), where he remained a towering presence for more than half a century. From his earliest days as a young engineer to his later years as a senior statesman of the profession, he treated the IESL not merely as an association but as a national institution with a duty to shape policy, uphold ethics, and safeguard the country’s engineering heritage.
His journey culminated in his election as President of the IESL, a tenure marked by his unwavering commitment to aligning engineering practice with national priorities—particularly in areas such as water resources, environmental stewardship, and indigenous technological development. Under his leadership, the IESL strengthened its voice in public policy debates and expanded its role as a guardian of professional standards.
16.Architect of Professional Unity: Sri Lanka’s Intellectual Institutions
Yet his influence extended far beyond engineering alone. Eng. Mendis was a natural bridge‑builder between disciplines, believing deeply that national progress required the collective intellect of all professions. This philosophy was evident in his leadership as President of Section C (Engineering, Surveying, and Architecture) of the Sri Lanka Association for the Advancement of Science (SLAAS), one of the country’s oldest and most respected scientific bodies. In this role, he championed interdisciplinary collaboration, encouraging engineers to engage with scientists, architects, surveyors, and researchers to address complex national challenges. His contributions helped strengthen SLAAS’s reputation as a forum where scientific inquiry and practical problem‑solving could meet.
His vision of professional unity reached its fullest expression in his instrumental role in establishing the Organization of Professional Associations (OPA) of Sri Lanka. Formed in the 1970s as a collective platform for the country’s major professional bodies, the OPA brought together engineers, doctors, lawyers, accountants, architects, and other specialists under one umbrella. Eng. Mendis recognised early that Sri Lanka needed a unified professional voice capable of advising government, shaping policy, and safeguarding the public interest. His advocacy helped transform the OPA into a respected national institution—one that continues to influence governance, legislation, and professional ethics.
To Eng. Mendis, the IESL, SLAAS, and OPA were not mere associations; they were the intellectual “think‑tanks” of the nation. He believed that when the rigor of engineering, the curiosity of science, and the analytical strength of the professions were brought together, Sri Lanka could chart a more ethical, sustainable, and enlightened path forward. His legacy within these institutions stands as a testament to his belief that knowledge, when organised and mobilised, is one of the most powerful forces for national development.
Conclusion
In 2007, our professional and personal bonds deepened through a project that was close to my heart. Although we were living in different countries, the invention of humankind, internet allowed us to remain connected with Eng Mendis. When I recreated the Miscellany of Hartley College, Point Pedro for the Hartley College Past Pupils Association (NSW, Australia), I reached out to him to honour the man who had first introduced us the late Prof. A. Thurairajah. Despite his demanding public commitments, he responded with characteristic grace, contributing a poignant and scholarly piece that enriched the publication and reaffirmed the depth of our friendship.
We will deeply miss Eng. Devaradura Lucius Oswald Mendis (D.L.O. Mendis) a decent, caring, friendly, and brilliant intellectual whose presence touched everyone around him. The Institution of Engineers, Sri Lanka carries a sensible responsibility to ensure that legacy continues to shine. Young engineers must come to understand that we lived in the time of an engineer whose pioneering vision linking engineering, ecology, and human habitats will endure in the hearts and minds of generations to come. His practical, ethical, and deeply implementable philosophy is now firmly rooted in the Sri Lankan engineering profession, guiding it long into the future. We shall remember Eng D L O Mendis as the engineer who reimagined our Nation and the role of engineers.