Cabinet decision to divert Kuda Ganga to Hambantota – A flawed decision?
Posted on February 1st, 2019

The Cabinet decision

The Cabinet of Ministers at its meeting held on 22.01.2019 has apparently granted approval for a project for preventing floods in the Ratnapura and Kalutara districts, and providing drinking water to the Hambantota district, by diverting Kuda Ganga, which is a tributary of the Kalu Ganga, as announced in the Cabinet Office website. The decision further says that a feasibility study has been carried out to implement the Kalu Ganga development project at an investment of Rs 123 billion, and has decided to call for proposals for Expression of Interest from International Construction Companies which can implement the project with foreign investment, to call for project proposals from eligible construction companies and to appoint a Cabinet Appointed Committee to evaluate the proposals.


Flaws in the decision

This Cabinet decision raises some doubts as to the feasibility of the project. Kuda Ganga described as a tributary of Kalu Ganga commences near Molkawa after the confluence of Kukule Ganga with Maguru Ganga and ends at Mabogoda where it confluences with Kalu Ganga. Though the Cabinet has decided to divert Kuda Ganga, technically it may not be feasible to do so because Kuda Ganga flows at an elevation below 20 m according to Survey Department toposheets. To divert this water, it is necessary to build a large reservoir and the topography there does not appear suitable for that even to a layman like the writer. It is surprising that such a flawed paper has been submitted by officials of the Ministry and got it approved. So, now, international bids are to be called based on this flawed decision.

Another flaw in the Cabinet decision is that though an objective of the project is said to prevent flooding in Ratnapura District, the diversion of Kuda Ganga will not achieve this objective. Flooding of Ratnapura town and its low-lying areas is caused during heavy rain by water surging down Kalu Ganga and Wey Ganga which confluence at Ratnapura town and not by waters flowing down Kuda Ganga which is in the Kalutara District. It appears that the officer who drafted the Cabinet paper does not know his basic geography.

Thirdly, the statement that a feasibility study on Kalu Ganga development has been carried out and according to this study, an investment of LKR 123 billion is required to implement the project. However, this study may not be referring to diverting Kuda Ganga, in view of the non-feasibility of diverting that river as stated above. It may be referring to diverting either Kalu Ganga or Kukule Ganga which has been attempted a few times in the past. If this is the case, the paper is only misleading the Cabinet. Attempts by the writer to get a copy of the annexure to the cabinet paper describing the project from the Ministry to find out which river is planned to be diverted were not successful.

Further, according to the Cabinet decision, this amount of money is to be raised through foreign investments. A foreigner will invest money in a project only if it will bring some return. Does it mean that water to be diverted to Hambantota will be sold to people there enabling the investor to get a return? Or, does the government plan to export the water diverted? What is the rationale for undertaking such a massive project where there are so many uncertainties? What is the urgency for the new minister to submit a poorly drawn up cabinet paper on such a massive project soon after he assumed office without properly understanding its history and verifying the facts?

Previous proposal to divert Kukule Ganga

Proposal to divert surplus Kalu Ganga water to water-deficit Hambantota is not a new one. The initial proposal to divert Kalu Ganga basin water to Hambantota was made more than 50 years ago by an American firm of consultants under the title “Three Basin River Development” covering the three rivers Kalu Ganga, Gin Ganga and Nilwala Ganga, published in 1968. Under the Kalu Ganga basin, the proposal was made to divert water from a large reservoir built across Kukule Ganga. This river commences from hills in the Sinharaja Forest and flows at an elevation more than 200 m. Diverted water is to be taken via a trans-basin canal, comprising both open segments and tunnels, referred to as the South East Dry Zone (SEDZ) canal to be built along the 120 m contour up to Lunugamvehera Reservoir. The report also recommended building a reservoir across Kalu Ganga at Meehitiya, 3 km upstream of Ratnapura Town to control flooding and develop hydro power. However, with priority given for the development of the Mahaweli River Projects in the 1970’s, the Kalu Ganga project was not pursued.

Kalu Ganga development was undertaken in the 1990’s when feasibility studies commenced to build a 100 m high dam across the Kukule Ganga near Kalawana for the purpose of developing hydro power and to take water from the reservoir to Lunugamvehera along the SEDZ canal. The rapid gradient of the river through 200 m elevation over a short distance made it an ideal site for hydropower development. The large reservoir formed with a high dam, however, was found to cause inundation of large extent of land including Kalawana Town with the water reaching the western boundary of the Sinharaja Forest, which was declared as a UNESCO World Heritage site. This prompted many environment organizations to raise objections including affected people in the area.

In view of its serious adverse environmental and social impacts and also considering protests from the public, this proposal has not been pursued, and instead a smaller pond with a 20 m high low dam was built to operate a run-of-the-river hydro power plant of capacity 70 MW, which was commissioned in 2003. Further, the German-based Lahmeyer International, who along with Skanska and Electrowatt formed part of the Skanska International Engineering Consortium (SIEC) that was responsible for planning the dam, found the geology in the area of the head pond unsuitable to build a high dam required for a large reservoir (

Proposal to build a reservoir at Ratnapura

A few years later, the diversion of the Kalu Ganga received renewed attention when the former President Mahinda Rajapaksa was reported to have said at a function of the new administrative complex in Hambantota in March 2006, that he wanted Kalu Ganga diverted to Ruhuna thereby solving two problems in one attempt, referring to the constant recurrence of floods in the Ratnapura and the occurrence of severe droughts in the Hambantota District, (Daily News of 13.03.2006).

Subsequently, several studies on preventing flooding due to spilling of Kalu Ganga waters have been undertaken including a study by a second American team, a Chinese Team, a Japanese team (JICA) and finally an Israel Team. All these teams have considered building a reservoir at Meehitiya to hold back the flood water, with varying sizes and hydro-power capacities along with other alternatives. However, according to Eng. G.T Dharmasena, a former Director General of Irrigation Department, this water cannot be diverted to Hambantota due to the low elevation of the Meehitiya reservoir site thogh it is feasible to have a reservoir there. Therefore, the benefit of Ratnapura reservoir would be for flood protection to Ratnapura city and for hydro power generation, but not for taking water to Hambantota as anticipated in the project (

JICA study on providing flood protection for Ratnapura

The Japan International Cooperation Agency (JICA) undertook a detailed study on Flood Management Planning for Kelani, Kalu, Gin and Nilwara Rivers and its report was published in March 2009. Part II of the report covered the Kalu Ganga basin which considered four alternatives as described in the Table 1 along with the estimated costs (

The comments made in the JICA report on the proposed alternatives are as follows:

“The reservoir of Malwala dam, which is planned in the upper streams of Kalu River is expected to be 4 km wide (East-West) and 8 km long (North-South). Due to the formulation of the reservoir, many communities will be submerged, which is expected to lead to the occurrence of involuntary resettlement for hundreds of households. Furthermore, the farmlands formulated in the bottom of the valleys, together with the gem mining sites in the river beds will vanish. The partial submerging of a B class national road crossing the area will spread its impact to other districts as well as the adjacent areas of the dam site. Furthermore, other factors that are expected to receive negative impact include; cultural / religious heritage, hydrology, flora/fauna and bio-diversity, landscape, and other factors relevant to construction work, and the overall negative impact of dam construction is expected to be significant. In order to minimize the impact of the dam and reservoir, a resettlement action plan with not only measures for land compensation, but also with clear measures to compensate for factors such as livelihood and economic activities must be prepared and implemented. Such action plan should be prepared based on detailed socio-economic surveys, disclosure of information/participation of local residents. Moreover, consensus on the resettlement action plan must be built with the local residents from the stage of preparation”.

“The economic analysis shows that Alternative I (flood bund) is most viable “Overall”, whereas “Short” term measures show smaller EIRR than those of Alternative IV (flood control purpose). The result of IEE shows that Alternative I is expected to have minimum negative impact among the four Alternatives. Further, since there is high potential for large scale involuntary resettlement for the Malwala Dam scheme, it was judged difficult to be implemented under present conditions. On the other hand, technical viability of the proposed works is almost equivalent among the four alternatives because the Government of Sri Lanka has experienced implementing similar structural measures and they do not involve any complex conditions and/or restrictions for design and construction phases. Hence, Alternative I was selected for the flood management master plan in the Kalu River basin”.



Feasibility study by Israel Consultants

Despite the fact that the JICA study has rejected the proposal to build a reservoir upstream of Ratnapura, the Ministry of Irrigation has entered into a Memorandum of Understanding (MOU) with TAHAL Engineering Ltd, in Israel, for Kalu Ganga development in January 2009. The development work was to take place in three phases.

i. Full feasibility study for Ratnapura reservoir. ii. Installation and calibration of the flood protection management model iii. Water Resources development study for the entire basin. According to the Ministry’s Performance Report for 2011, the Consultants were mobilized by 2011 and the prefeasibility study in the whole “Kalu Ganga” basin was going on. The consultants were also carrying out the prefeasibility study to identify the possible locations for reservoirs. It is baffling for anyone to note that Sri Lanka seeks advice on water resources from consultants coming from a desert country.


When the team visited homesteads to carry out the survey and fix stakes marking boundaries of areas getting inundated by the proposed 100 m high reservoir, people got concerned and started demonstrations expressing their protests. People argued that there was no rationale for inundating their land permanently to give relief to people in Kalutara District whose land gets inundated by floods only occasionally. They also cited previous instances when people who got displaced from such development activities were given land in alien areas lacking resources to maintain a sustainable livelihood.

It was subsequently revealed that this work was being carried out on a directive from the Secretary to the Irrigation Ministry who had issued a circular dated 02.08.2011 to the District Secretaries of Ratnapura and Kalutara Districts with copies to all Divisional Secretaries and Chairmen of all Pradesheeya Sabha in the two districts, apprising them of a ministry decision to undertake a feasibility study for the purpose of developing water resources in the Kalu Ganga basin and finding solutions to minimize the flood damage. However, the project was later abandoned on a political decision due to public protests as announced by the Minister himself at a public meeting held at Malwala Temple to apprise the public about the Government’s decision. The meeting was attended by two Ministers representing Ratnapura District and by the secretary to the Irrigation Ministry. The exercise of this futile study done by the Israel Consultants against the findings of the JICA would have cost an enormous sum of money, and who is responsible for this expenditure?

Despite this decision, more recently, in October 2018, at a meeting held at the Ratnapura District Secretariat, Minister Patali Champika Ranawaka was reported to having said that “as a permanent solution to the occurrence of floods frequently experienced in the Ratnapura and Kalutara districts, a dam will be constructed across the Kalu Ganga in Malwala, close to Ratnapura town. The Kalu Ganga will also be diverted up to Hambantota via Embilipitiya through a tunnel”, the Minister said (Daily News of 18.10.2018). It appears that the Minister was not aware of the previous attempts to build a reservoir across Kalu Ganga at Meehitiya and how the plans were abandoned. So, now he wants to start the exercise again, probably to end up in a dead-end again. Doesn’t the minister realize that making such a statement on a project twice rejected by the people will only give wrong signals to the people.

Need for diverting surplus Kalu Ganga water to the South

Kalu Ganga is Sri Lanka’s third longest river (110 km) originating from Adam’s Peak at an elevation over 2000 m above mean sea level (amsl) discharging annually about 4,000 million cubic metres of water to the sea at Kalutara. Several tributaries carry water to Kalu Ganga from a wide catchment area, and these include Kuru Ganga, Kuda Ganga (after confluencing Kukule Ganga and Maguru Ganga), Wey Ganga, Denawak Ganga and Rath Ganga. During heavy rain, the last three rivers along with the upstream of Kalu Ganga bring large amounts of flood water flowing down at high gradient to the town. From thereon the flow is slow as the low gradient of 0.15 m/km from Ratnapura to Kalutara is not adequate enough to remove these flood waters as rapidly as the incoming water and hence the frequent flooding.

While the regular monsoon rains bring minor floods inundating the low-lying areas at Ratnapura, occasional torrential rains caused by cyclonic storms originating in the Bay of Bengal once in several years cause major floods inundating land extensively both in the Ratnapura and Kalutara Districts. Such major floods had occurred in recent times in 1992, 2003, 2010, 2014, 2016 and more recently in 2017, causing many casualties and billions of rupee property damage. Hence, flood protection has been at the top of the development agenda at Ratnapura.

Though government after government has been attempting to divert Kalu Ganga surplus water to the South, no workable solution could be reached hitherto because of technical, social and environmental issues. Building a high dam across Kukule Ganga was not found feasible because of poor geology, public protests and being close to the Sinharja Forest. Further, it will not solve the flood problem at Ratnapura town. Even building a high dam across Kalu Ganga at Meehitiya is questionable because the adjoining hills are prone to land-slides as indicated on a warning sign board erected by the Disaster Management Centre in close proximity to the site. Further, it is technically not feasible to take water to Hambantota from a reservoir there and owing to public protests, the project had to be abandoned. Hence, inviting proposals from foreign parties to invest on the proposed diversion which ran into problems previously without first alerting the people and getting their consent will most likely be a futile exercise again.

An alternative proposal to prevent flooding and take water to Hambantota

In view of the impasse as described above in building reservoirs across Kalu Ganga and Kukule Ganga, the writer proposed an alternative scheme for taking surplus water from Kalu Ganga to the South, which was published in the Island of 12th and 14th of November 2011, under the caption “Flood protection at Ratnapura and taking surplus water to Ruhuna- An alternative scheme”. This article could be accessed via:, and

If taking water from a reservoir at Meehitiya to the South is not feasible because of its low elevation, then the solution is to tap the river at a higher elevation. Meehitiya Reservoir is to receive water from the main Kalu Ganga and two of its tributaries Rath Ganga and Denawak Ganga fed by Bambarakotuwa (BK) Oya. Both these rivers, originating from the Southern wall of the Adam’s Peak Range, cover a larger catchment area than the Kalu Ganga which originates from the Peak. If one examines the path traced by these two waterways, it is possible to identify suitable locations where small reservoirs could be built at elevations high enough to feed water to a trans-basin canal for taking water to Ruhuna. Details of the proposed locations are given in the writer’s original article.

Rath Ganga flows past the 300 m and 200 m contours at Raththurugala and a bund could be built with its base at about 200 m elevation and crest below 300 m. On the BK Oya, two waterways join the river slightly below 200 m elevation near Batewela and a reservoir could be built just below the confluence. A tunnel dug through the hills in between at 200 m elevation could take water from the first reservoir to this second. A third reservoir could be built on the upstream of Wey Ganga near Madole where the river crosses the 200 m contour. Water from the second reservoir could be taken to this third reservoir through a tunnel linking the two.

A third tunnel could take water from this third reservoir to Medagan Oya which runs below 200 m elevation and this water could then be fed to the proposed SEDZ canal running at 120 m. If the outlet of this tunnel is located at an appropriate location, it should be possible to get a head of at least 50 m enabling the operation of a medium size hydro power plant. The project involves building three small reservoirs and three tunnels of total length of about 33 km, all within the capability of Sri Lankans. Thus, with this project, it is possible to fulfill the three objectives listed – flood protection of Kalu Ganga basin, supplying water to Ruhuna and harnessing water to generate hydroelectricity. Since this scheme does not involve building large reservoirs, no public protests are anticipated. A concept paper describing the above alternative project was submitted to the President’s Office, Minister’s office, Secretary’s office in early 2012, but none responded.

Need for public awareness of the proposed project

The writer made several attempts to get information on the proposed diversion project to clarify which river is planned to be diverted, whether Kuda Ganga as mentioned in the Cabinet decision, or Kalu Ganga or Kukule Ganga where previous proposals for diversion were made. Regrettably, no positive response could be obtained. What the officers do not realize is that though plans and decisions are made behind doors, their implementation has to be done in public. In view of the wide range of potential negative impacts, it is the responsibility of the authorities to make the public aware of their plans at the conceptual stage itself and get their consent to proceed, rather than do it at the final stage after spending a lot of money on designs and studies and then forced to abandon, as happened in the past.

Since a feasibility report is said to be already available, an opportunity should have been given to a professional/academic forum to deliberate on it before submitting the proposal to the Cabinet. Had this been done, the many shortcomings in the cabinet paper could have been avoided. Now the project is approved by the Cabinet, it is desirable if the Ministry commences immediately a publicity campaign through both print and electronic media to make the public aware of the proposed project, its benefits and plans for resettlement, so that they will not be taken by surprise when foreign consultants visit their homestead to carry out surveys. The sooner it is done, the better it is.

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