Features
The Salinity Barrier and Nilwala Floods: Clearing up Misconceptions
by Dr. R. Galappatti,
Chairman, Lanka Hydraulic Institute (LHI).
Introduction
Recent experience of high water levels in lower reaches of the Nilwala Ganga has been attributed by various parties to the construction of the Salinity Barrier in 2018-2022, 5.4 km upstream of the sea outfall. While it is understandable that the affected communities would blame the most recent construction in the river channel for this, many technically qualified persons have also subscribed to this view without either examining hydraulic computations or making any measurements at the barrier. We are concerned that ill-considered attempts are being made to interfere with the structural integrity of the barrier and endanger a major piece of water supply infrastructure.
The salinity barrier is designed to protect the water supply intakes from salinity intrusion and ensure an uninterrupted supply of drinking water to around 600,000 consumers by the year 2035, in the Matara and Hambantota districts, under the Matara Stage IV Water Supply Project of the National Water Supply & Drainage Board (NWSDB). The conceptual design of the barrier including its dimensions, levels and operating rules was carried out by Lanka Hydraulic Institute (LHI).
Regular review meetings were held at regional level by the NWSDB with participation of the Irrigation Department. The Central Engineering Consultancy Bureau (CECB), the EIA consultant, also participated, with full access to the details of the ongoing work at all stages of the study. Modifications were made to the study approach and the designs as required.
The hydraulic studies including design calculations were carried out and the main parameters of the barrier were determined and verified using physical and numerical model studies. This focused on the salinity barrier, particularly its flood impacts, and led to a positive EIA report after public consultations were completed. Detailed designs and construction of the barrier was carried out by a Korean Company (Kolon Samsung C&T) with Ceywater as the local design partner under a Design-Build contract.
The Salinity Barrier
The final design consists of providing a 5-bay gated type structure with vertical lifting gates and piers across the inner stream section 5.4 km upstream of the sea mouth, in the river reach between Thudawa Pump station and Navimana ferry crossing. The gates are 10m wide and 3.1m high with the gate sill fixed at –2.5 m MSL. Gate top at closed position is at +0.6 m MSL and the gate bottom in fully open position is to be at 5m MSL during high and normal flow conditions. This level is above the High Flood Level, as the top level of the flood bund is only around 4.3 m MSL.
Three of the five gates were to be made of two separate sections to allow the upper section to be lowered independently, to make it possible to lower the upstream pool level when necessary for irrigation water management at the request of the Irrigation Department. Sheet-pile cut-off walls were provided across the low-lying areas of the flood plain on either bank to prevent saline water bypassing the main structure during operation and to ensure that during dry weather the river flow is confined to the inner channel and not to overflow into the floodplain. In addition to these main features, gate operating structures, cut-off walls, access roads etc. were included in the design.
The barrier is in full conformity to the stipulations in the MOU signed between NWSDB and the Irrigation Department in March 2017, and the Irrigation Department granted approval for the NWSDB to implement the project.
Figure 2: Salinity Barrier across Nilwala River
Impacts of the Salinity Barrier
The increase in river water level during floods, and operating conditions and concerns of the stakeholders due the proposed structure, were the main considerations in determining optimal values for gate openings, gate sill levels and other parameters for the design.
The upstream flooding impact of the barrier design was computed using a numerical model and verified by carrying out a series of physical model tests at Lanka Hydraulic Institute (LHI). These were used to verify that the flow pattern around and downstream of the gated structure was satisfactory.
The water levels in the upstream river reach, with and without the barrier, were estimated for different flow conditions including floods up to 100 yr return period. The estimated anticipated water level rise just upstream of the Salinity Barrier was about 1 cm maximum during floods of 100 yr return period. There was a higher (4-7 cm) relative water level rise during bank full and low return period floods.
Backwater propagation lengths have been calculated and these anticipated water level rises were considered acceptable. It is relevant to note that, the acceptable head loss at the planned Kelani Ganga salinity barrier was fixed in the range 5 cm to 6 cm for a 100 yr flood.
As far as the flood impact of the cut-off wall is concerned, the impact will be negligible because this wall, with a top level of only 0.8 m MSL, will be well and truly submerged during a major flood. Further there is an allegation that debris might trap buildup from the river bed level to the sill level of gates, and exacerbate flooding. Even if debris are accumulated, its total hydraulic impact is still negligible. Further, fresh bathymetric survey conducted in Dec 2023 has even revealed that there is in fact no debris accreted upstream of the gate structure.
Long inundation period during present flood compared to previous floods
While it has been demonstrated that construction of the Salinity Barrier is not the cause of recent floods, it is nevertheless necessary to investigate why this long inundation of paddy lands occurred and determine what actions need to be taken to prevent or reduce the probability of a recurrence.
In this context it is necessary to examine what happened in May 2017 when there was an extreme flood event in this basin. The flood was caused by an extreme rainfall event of about three days duration that caused a sharp flood peak reaching a daily average water level of 4.32 m MSL at Thalagahagoda on the very next day. The water levels receded to normal levels within the next ten days while it took seven days to decrease to flood alert level (1.4 m MSL) at Thalagahagoda. The return period of this flood is said to be between 75 and 100 yr.
Figure 4: Rainfall Pattern and Drawdown of Water Levels during 2017 Flood
The duration of the long series of rainfall events that spread out over more than two months from Mid-September to end November 2023 is markedly different – both from the point of view of the basin and the time of the year when it took place. While the water level at Thalagahagoda peaked only at 2.92 m MSL in 2023, the level continued to stay above 1.7 m MSL (Minor flood level) for almost the entire period (Oct to mid of Nov).
Figure 3: Rainfall Pattern and Drawdown of Water Levels during Sep Oct 2023 Flood (06th Sep – 22nd Nov 2023)
The markedly different nature of this flood – including its extremely slow recession could only be explained by considering the retention (storage) of flood water on the flood plain which is divided into two on either side of the Nilwala flood bund. The area adjacent to the river will drain slowly into the river channel in the normal manner. The water collecting in the “protected area” must be pumped out at a few pumping stations located along the flood bund.
Duration of operation of these pumps is on record but their pumping rate is not known. An additional point to be considered is that the measured water level profile on the short river reach downstream of the barrier show a steeper slope indicating a more constricted channel from the railway bridge to the sea.
It is also important to note that the rainfall pattern in 2023 is unusual and unexpected, and that no usual rainfall runoff model could accurately interpret it. The models, in turn, must be more detailed, to include the flood plain storage and pumping rates to represent the flood routing performance of the system under such unusual rainfall patterns which might be a trend caused by climate change.
It must also be borne in mind that the Nilwala basin is not a stranger to flooding, though not so late in the year. The steep upper basin that descends suddenly into a largely flat coastal plain is characteristic of all large wet zone rivers in Sri Lanka.
Conclusions
The long-duration flooding experience in the Nilwala basin in 2023 has not been caused by the construction of the Salinity Barrier.A more detailed representation of the flood plains and pump operation is needed to quantify accurately the long recession of the flood plain
The marked change in rainfall patterns might be due to a climate change effect and this type of effect might also impact other river basins in the wet zone. This requires attention.
The ill- considered removal of the low cut-off wall across the lower floodplain should be restored to avoid possible shut down of water supply intakes in the next dry season.
by Dr Gotabhya Ranasinghe
Senior Consultant Cardiologist
National Hospital Sri Lanka
When we sought a meeting with Hon Dr. Ramesh Pathirana, Minister of Health, he graciously cleared his busy schedule to accommodate us. Renowned for his attentive listening and deep understanding, Minister Pathirana is dedicated to advancing the health sector. His openness and transparency exemplify the qualities of an exemplary politician and minister.
Dr. Palitha Mahipala, the current Health Secretary, demonstrates both commendable enthusiasm and unwavering support. This combination of attributes makes him a highly compatible colleague for the esteemed Minister of Health.
Our discussion centered on a project that has been in the works for the past 30 years, one that no other minister had managed to advance.
Minister Pathirana, however, recognized the project’s significance and its potential to revolutionize care for heart patients.
The project involves the construction of a state-of-the-art facility at the premises of the National Hospital Colombo. The project’s location within the premises of the National Hospital underscores its importance and relevance to the healthcare infrastructure of the nation.
This facility will include a cardiology building and a tertiary care center, equipped with the latest technology to handle and treat all types of heart-related conditions and surgeries.
Securing funding was a major milestone for this initiative. Minister Pathirana successfully obtained approval for a $40 billion loan from the Asian Development Bank. With the funding in place, the foundation stone is scheduled to be laid in September this year, and construction will begin in January 2025.
This project guarantees a consistent and uninterrupted supply of stents and related medications for heart patients. As a result, patients will have timely access to essential medical supplies during their treatment and recovery. By securing these critical resources, the project aims to enhance patient outcomes, minimize treatment delays, and maintain the highest standards of cardiac care.
Upon its fruition, this monumental building will serve as a beacon of hope and healing, symbolizing the unwavering dedication to improving patient outcomes and fostering a healthier society.We anticipate a future marked by significant progress and positive outcomes in Sri Lanka’s cardiovascular treatment landscape within the foreseeable timeframe.
by Fr. Emmanuel Fernando, OMI
Jesuit Fr. Aloysius Pieris (affectionately called Fr. Aloy) celebrated his 90th birthday on April 9, 2024 and I, as the editor of our Oblate Journal, THE MISSIONARY OBLATE had gone to press by that time. Immediately I decided to publish an article, appreciating the untiring selfless services he continues to offer for inter-Faith dialogue, the renewal of the Catholic Church, his concern for the poor and the suffering Sri Lankan masses and to me, the present writer.
It was in 1988, when I was appointed Director of the Oblate Scholastics at Ampitiya by the then Oblate Provincial Fr. Anselm Silva, that I came to know Fr. Aloy more closely. Knowing well his expertise in matters spiritual, theological, Indological and pastoral, and with the collaborative spirit of my companion-formators, our Oblate Scholastics were sent to Tulana, the Research and Encounter Centre, Kelaniya, of which he is the Founder-Director, for ‘exposure-programmes’ on matters spiritual, biblical, theological and pastoral. Some of these dimensions according to my view and that of my companion-formators, were not available at the National Seminary, Ampitiya.
Ever since that time, our Oblate formators/ accompaniers at the Oblate Scholasticate, Ampitiya , have continued to send our Oblate Scholastics to Tulana Centre for deepening their insights and convictions regarding matters needed to serve the people in today’s context. Fr. Aloy also had tried very enthusiastically with the Oblate team headed by Frs. Oswald Firth and Clement Waidyasekara to begin a Theologate, directed by the Religious Congregations in Sri Lanka, for the contextual formation/ accompaniment of their members. It should very well be a desired goal of the Leaders / Provincials of the Religious Congregations.
Besides being a formator/accompanier at the Oblate Scholasticate, I was entrusted also with the task of editing and publishing our Oblate journal, ‘The Missionary Oblate’. To maintain the quality of the journal I continue to depend on Fr. Aloy for his thought-provoking and stimulating articles on Biblical Spirituality, Biblical Theology and Ecclesiology. I am very grateful to him for his generous assistance. Of late, his writings on renewal of the Church, initiated by Pope St. John XX111 and continued by Pope Francis through the Synodal path, published in our Oblate journal, enable our readers to focus their attention also on the needed renewal in the Catholic Church in Sri Lanka. Fr. Aloy appreciated very much the Synodal path adopted by the Jesuit Pope Francis for the renewal of the Church, rooted very much on prayerful discernment. In my Religious and presbyteral life, Fr.Aloy continues to be my spiritual animator / guide and ongoing formator / acccompanier.
Fr. Aloysius Pieris, BA Hons (Lond), LPh (SHC, India), STL (PFT, Naples), PhD (SLU/VC), ThD (Tilburg), D.Ltt (KU), has been one of the eminent Asian theologians well recognized internationally and one who has lectured and held visiting chairs in many universities both in the West and in the East. Many members of Religious Congregations from Asian countries have benefited from his lectures and guidance in the East Asian Pastoral Institute (EAPI) in Manila, Philippines. He had been a Theologian consulted by the Federation of Asian Bishops’ Conferences for many years. During his professorship at the Gregorian University in Rome, he was called to be a member of a special group of advisers on other religions consulted by Pope Paul VI.
Fr. Aloy is the author of more than 30 books and well over 500 Research Papers. Some of his books and articles have been translated and published in several countries. Among those books, one can find the following: 1) The Genesis of an Asian Theology of Liberation (An Autobiographical Excursus on the Art of Theologising in Asia, 2) An Asian Theology of Liberation, 3) Providential Timeliness of Vatican 11 (a long-overdue halt to a scandalous millennium, 4) Give Vatican 11 a chance, 5) Leadership in the Church, 6) Relishing our faith in working for justice (Themes for study and discussion), 7) A Message meant mainly, not exclusively for Jesuits (Background information necessary for helping Francis renew the Church), 8) Lent in Lanka (Reflections and Resolutions, 9) Love meets wisdom (A Christian Experience of Buddhism, 10) Fire and Water 11) God’s Reign for God’s poor, 12) Our Unhiddden Agenda (How we Jesuits work, pray and form our men). He is also the Editor of two journals, Vagdevi, Journal of Religious Reflection and Dialogue, New Series.
Fr. Aloy has a BA in Pali and Sanskrit from the University of London and a Ph.D in Buddhist Philosophy from the University of Sri Lankan, Vidyodaya Campus. On Nov. 23, 2019, he was awarded the prestigious honorary Doctorate of Literature (D.Litt) by the Chancellor of the University of Kelaniya, the Most Venerable Welamitiyawe Dharmakirthi Sri Kusala Dhamma Thera.
Fr. Aloy continues to be a promoter of Gospel values and virtues. Justice as a constitutive dimension of love and social concern for the downtrodden masses are very much noted in his life and work. He had very much appreciated the commitment of the late Fr. Joseph (Joe) Fernando, the National Director of the Social and Economic Centre (SEDEC) for the poor.
In Sri Lanka, a few religious Congregations – the Good Shepherd Sisters, the Christian Brothers, the Marist Brothers and the Oblates – have invited him to animate their members especially during their Provincial Congresses, Chapters and International Conferences. The mainline Christian Churches also have sought his advice and followed his seminars. I, for one, regret very much, that the Sri Lankan authorities of the Catholic Church –today’s Hierarchy—- have not sought Fr.
Aloy’s expertise for the renewal of the Catholic Church in Sri Lanka and thus have not benefited from the immense store of wisdom and insight that he can offer to our local Church while the Sri Lankan bishops who governed the Catholic church in the immediate aftermath of the Second Vatican Council (Edmund Fernando OMI, Anthony de Saram, Leo Nanayakkara OSB, Frank Marcus Fernando, Paul Perera,) visited him and consulted him on many matters. Among the Tamil Bishops, Bishop Rayappu Joseph was keeping close contact with him and Bishop J. Deogupillai hosted him and his team visiting him after the horrible Black July massacre of Tamils.
Sri Lanka-Singapore Free Trade Agreement
By Gomi Senadhira
senadhiragomi@gmail.com
“You might tell fairy tales, but the progress of a country cannot be achieved through such narratives. A country cannot be developed by making false promises. The country moved backward because of the electoral promises made by political parties throughout time. We have witnessed that the ultimate result of this is the country becoming bankrupt. Unfortunately, many segments of the population have not come to realize this yet.” – President Ranil Wickremesinghe, 2024 Budget speech
Any Sri Lankan would agree with the above words of President Wickremesinghe on the false promises our politicians and officials make and the fairy tales they narrate which bankrupted this country. So, to understand this, let’s look at one such fairy tale with lots of false promises; Ranil Wickremesinghe’s greatest achievement in the area of international trade and investment promotion during the Yahapalana period, Sri Lanka-Singapore Free Trade Agreement (SLSFTA).
It is appropriate and timely to do it now as Finance Minister Wickremesinghe has just presented to parliament a bill on the National Policy on Economic Transformation which includes the establishment of an Office for International Trade and the Sri Lanka Institute of Economics and International Trade.
Was SLSFTA a “Cleverly negotiated Free Trade Agreement” as stated by the (former) Minister of Development Strategies and International Trade Malik Samarawickrama during the Parliamentary Debate on the SLSFTA in July 2018, or a colossal blunder covered up with lies, false promises, and fairy tales? After SLSFTA was signed there were a number of fairy tales published on this agreement by the Ministry of Development Strategies and International, Institute of Policy Studies, and others.
However, for this article, I would like to limit my comments to the speech by Minister Samarawickrama during the Parliamentary Debate, and the two most important areas in the agreement which were covered up with lies, fairy tales, and false promises, namely: revenue loss for Sri Lanka and Investment from Singapore. On the other important area, “Waste products dumping” I do not want to comment here as I have written extensively on the issue.
1. The revenue loss
During the Parliamentary Debate in July 2018, Minister Samarawickrama stated “…. let me reiterate that this FTA with Singapore has been very cleverly negotiated by us…. The liberalisation programme under this FTA has been carefully designed to have the least impact on domestic industry and revenue collection. We have included all revenue sensitive items in the negative list of items which will not be subject to removal of tariff. Therefore, 97.8% revenue from Customs duty is protected. Our tariff liberalisation will take place over a period of 12-15 years! In fact, the revenue earned through tariffs on goods imported from Singapore last year was Rs. 35 billion.
The revenue loss for over the next 15 years due to the FTA is only Rs. 733 million– which when annualised, on average, is just Rs. 51 million. That is just 0.14% per year! So anyone who claims the Singapore FTA causes revenue loss to the Government cannot do basic arithmetic! Mr. Speaker, in conclusion, I call on my fellow members of this House – don’t mislead the public with baseless criticism that is not grounded in facts. Don’t look at petty politics and use these issues for your own political survival.”
I was surprised to read the minister’s speech because an article published in January 2018 in “The Straits Times“, based on information released by the Singaporean Negotiators stated, “…. With the FTA, tariff savings for Singapore exports are estimated to hit $10 million annually“.
As the annual tariff savings (that is the revenue loss for Sri Lanka) calculated by the Singaporean Negotiators, Singaporean $ 10 million (Sri Lankan rupees 1,200 million in 2018) was way above the rupees’ 733 million revenue loss for 15 years estimated by the Sri Lankan negotiators, it was clear to any observer that one of the parties to the agreement had not done the basic arithmetic!
Six years later, according to a report published by “The Morning” newspaper, speaking at the Committee on Public Finance (COPF) on 7th May 2024, Mr Samarawickrama’s chief trade negotiator K.J. Weerasinghehad had admitted “…. that forecasted revenue loss for the Government of Sri Lanka through the Singapore FTA is Rs. 450 million in 2023 and Rs. 1.3 billion in 2024.”
If these numbers are correct, as tariff liberalisation under the SLSFTA has just started, we will pass Rs 2 billion very soon. Then, the question is how Sri Lanka’s trade negotiators made such a colossal blunder. Didn’t they do their basic arithmetic? If they didn’t know how to do basic arithmetic they should have at least done their basic readings. For example, the headline of the article published in The Straits Times in January 2018 was “Singapore, Sri Lanka sign FTA, annual savings of $10m expected”.
Anyway, as Sri Lanka’s chief negotiator reiterated at the COPF meeting that “…. since 99% of the tariffs in Singapore have zero rates of duty, Sri Lanka has agreed on 80% tariff liberalisation over a period of 15 years while expecting Singapore investments to address the imbalance in trade,” let’s turn towards investment.
Investment from Singapore
In July 2018, speaking during the Parliamentary Debate on the FTA this is what Minister Malik Samarawickrama stated on investment from Singapore, “Already, thanks to this FTA, in just the past two-and-a-half months since the agreement came into effect we have received a proposal from Singapore for investment amounting to $ 14.8 billion in an oil refinery for export of petroleum products. In addition, we have proposals for a steel manufacturing plant for exports ($ 1 billion investment), flour milling plant ($ 50 million), sugar refinery ($ 200 million). This adds up to more than $ 16.05 billion in the pipeline on these projects alone.
And all of these projects will create thousands of more jobs for our people. In principle approval has already been granted by the BOI and the investors are awaiting the release of land the environmental approvals to commence the project.
I request the Opposition and those with vested interests to change their narrow-minded thinking and join us to develop our country. We must always look at what is best for the whole community, not just the few who may oppose. We owe it to our people to courageously take decisions that will change their lives for the better.”
According to the media report I quoted earlier, speaking at the Committee on Public Finance (COPF) Chief Negotiator Weerasinghe has admitted that Sri Lanka was not happy with overall Singapore investments that have come in the past few years in return for the trade liberalisation under the Singapore-Sri Lanka Free Trade Agreement. He has added that between 2021 and 2023 the total investment from Singapore had been around $162 million!
What happened to those projects worth $16 billion negotiated, thanks to the SLSFTA, in just the two-and-a-half months after the agreement came into effect and approved by the BOI? I do not know about the steel manufacturing plant for exports ($ 1 billion investment), flour milling plant ($ 50 million) and sugar refinery ($ 200 million).
However, story of the multibillion-dollar investment in the Petroleum Refinery unfolded in a manner that would qualify it as the best fairy tale with false promises presented by our politicians and the officials, prior to 2019 elections.
Though many Sri Lankans got to know, through the media which repeatedly highlighted a plethora of issues surrounding the project and the questionable credentials of the Singaporean investor, the construction work on the Mirrijiwela Oil Refinery along with the cement factory began on the24th of March 2019 with a bang and Minister Ranil Wickremesinghe and his ministers along with the foreign and local dignitaries laid the foundation stones.
That was few months before the 2019 Presidential elections. Inaugurating the construction work Prime Minister Ranil Wickremesinghe said the projects will create thousands of job opportunities in the area and surrounding districts.
The oil refinery, which was to be built over 200 acres of land, with the capacity to refine 200,000 barrels of crude oil per day, was to generate US$7 billion of exports and create 1,500 direct and 3,000 indirect jobs. The construction of the refinery was to be completed in 44 months. Four years later, in August 2023 the Cabinet of Ministers approved the proposal presented by President Ranil Wickremesinghe to cancel the agreement with the investors of the refinery as the project has not been implemented! Can they explain to the country how much money was wasted to produce that fairy tale?
It is obvious that the President, ministers, and officials had made huge blunders and had deliberately misled the public and the parliament on the revenue loss and potential investment from SLSFTA with fairy tales and false promises.
As the president himself said, a country cannot be developed by making false promises or with fairy tales and these false promises and fairy tales had bankrupted the country. “Unfortunately, many segments of the population have not come to realize this yet”.
(The writer, a specialist and an activist on trade and development issues . )
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