Revisiting ongoing Upper Elahera Canal project

By Neville Ladduwahetty

The Upper Elahera Canal (UEC) was conceived with the objective of transferring water from the Moragakanda Reservoir in the Central Province to existing reservoirs in the North Central Province and eventually to water deficit areas in the North via a 92-km canal that includes a 27.7-km tunnel. The UEC is designed to convey 974 MCM (Million Cubic Meters) of water annually. This design capacity is based on the premise that 772 MCM of water would be transferred north starting from Randenigala to Moragahakanda through a series of reservoirs and canals, first to Kalu Ganga and eventually to Moragahakanda.

Since the infrastructure needed to transfer 772 MCM from Randenigala has not commenced, and is not likely to become operational for well over a decade, the only water that would be available at Moragahakanda during the interim would be what is transferred from Bowatenna (496 MCM) and from its own catchment (344 MCM) making a total of 840 MCM. However, before any water could be conveyed to the North Central Province through the UEC, water has to be diverted to the Minneriya Yoda Ela (617 MCM) to irrigate lands served by Minneriya, Kaudulla, Kantalai and Giritale tanks. This leaves ONLY 223 MCM to be conveyed by the UEC to the North Central Province.

Although the UEC is being constructed to convey 974 MCM, ONLY 223 MCM of water would be available for transfer through the UEC to the North Central Province until water could be transferred from Randenigala. This means that ONLY 23 % of the capacity of the UEC would be utilised. Since this situation would prevail for well over a decade, serious attention should be given to evaluate how best to utilise the available 223 MCM to meet the demands of the North Central Province.

The data presented above is from an ADB Technical Assistance Consultant’s Report titled “Sri Lanka: Water Resources Development Investment Program” for the Ministry of Irrigation and Water Resource Management dated December 2014, Paragraph 21, p. 343, Project No. 47381.

WATER DEMANDS in the NORTH CENTRAL PROVINCE

According to the Executive Summary of the Environment Impact Assessment Report of December 2014 for the Ministry of Irrigation and Water Resources Management prepared by Mahaweli Consultancy Bureau (MCB), the UEC is to transfer water from Moragahakanda reservoir to Mannankattiya reservoir in the North Central Province where it divides into two branches; the Manankattiya-Eruwewa-Mahakandarawa and Huruluwewa. Improvements to existing water conveyance systems in each branch is an integral part of the UEC Project.

“The studies by the MCB show that 281 MCM is intended to be transferred at Manankattiya outlet with 155 MCM to Manankattiya-Eruwewa-Mahakandarawa and 126 MCM to Huruluwewa (MCB,2012 b). With these transfers, it is planned to increase the cropping intensity from around 1.2 to 1.8 (MCB, 2012a)” (Ibid).

The significance of the comment “increase the cropping intensity” means that 281 MCM is available for both seasons Maha and Yala. However, since these reservoirs would receive sufficient water from the North-East Monsoon at least for the Maha crop, the quantity of water needed for Yala could generously be assumed to be half of 281 MCM which is 140 MCM to be conveyed to the North Central Province via the UEC. This leaves a balance of 223 MCM less 140 MCM, which is 83 MCM, from which 70 MCM could be used as raw water for domestic needs. This means that practically all of the 223 MCM conveyed by the UEC would be needed to meet the demands in the North Central Province.

EXISTENTIAL REALTIES

In the absence of the needed infrastructure to transfer 772 MCM from Randenigala to Moragahakanda, the existential reality is that ONLY 223 MCM is available to meet the agricultural and domestic demands of the North Central Province. The other existential reality is that IF the infrastructure needed to transfer 772 MCM from Randenigala to Moragahakanda is in place and functioning, the UEC would be transferring its full design capacity of 974 MCM to the North Central and Northern Provinces.

THEREFORE, THE TRANSFER OF WATER VIA THE UEC PRESENTS TWO PHASES.

PHASE I: THE UEC TO TRANSFER ONLY 223 MCM TO THE NORTH CENTRAL PROVINCE UNTIL THE CONSTRUCTION OF THE INFRASTRUCTURE TO TRANSFER WATER FROM RANDENIGALA TO MORAGAHAKANDA IS COMPLETED. DURING THIS PHASE, SINCE 223 MCM MEETS ONLY THE DEMANDS OF THE NORTH CENTRAL PROVINCE, NO WATER WOULD BE AVAILABLE VIA THE UEC FOR THE NORTHERN PROVINCE. THEREFORE, THE NORTHERN PROVINCE WOULD HAVE TO DEVELOP INDEPENDENT INFRASTRUCTURE TO HARNESS THE NORTH-EAST MONSOONAL RAINS.

PHASE II: TO TRANSFER THE DESIGN CAPACITY OF 974 MCM TO THE NORTH CENTRAL AND NORTHERN PROVINCES, WHEN THE INFRASTRUCTURE NEEDED TO TRANSFER WATER FROM RANDENIGALA TO MORAGAHAKANDA IS COMPLETED. DURING THIS PHASE, 223 MCM OUT OF THE 974 MCM WOULD BE DIVERTED TO MEET THE DEMANDS OF THE NORTH CENTRAL PROVINCE WITH THE BALANCE OF 751 MCM BEING TRANSFERRED TO THE NORTHERN PROVINCE. CURRENTLY, THE NORTHERN PROVINCE IS NOT EQUIPPED WITH THE NEEDED INFRASTRUCTURE TO ACCOMMODATE 751 MCM OF WATER.

THUS, UNDER EITHER PHASE, ADDITIONAL INFRASTRUCTURE WOULD BE NEEDED IN THE NORTHERN PROVINCE; A FACT THAT HAS NOT BEING ADDRESSED HITHERTO.

MAKING HARD CHOICES

What is evident from either option is that infrastructure of one form or another is needed in the Northern Province, regardless of the option chosen. That being the case, the choice made would depend on cost and which option would make sense. Since the transfer of water from Randenigala would mostly be from the North-East Monsoon and since the same Monsoon brings rain water to the Northern Province, it makes absolutely no sense to transfer water from the South to the North. What would make far more sense instead, is to harness the Monsoonal rains that fall in the Northern Province as stated under Option I. Furthermore, since the UEC would be transferring only 223 MCM, the scale of the UEC that is being constructed should be considerably reduced and therefore less costly than what is being constructed. In addition, factoring in the savings that would arise by not investing in the infrastructure needed to transfer water from Randenigala to Moragahakanda, it would ensure further cost savings which, taken together would be considerable.

CONCLUSION

What is proposed earnestly and seriously, is that an appeal to the Ministry of Irrigation and Water Resources Management and to the Mahaweli Authority be made to rethink and abandon all Projects associated with the prospect of transferring water from Randenigala to Moragahakanda. The immediate consequence of accepting what is proposed would be to seriously scale down the scope of the Upper Elahera Canal that is currently being constructed, from its ability to transfer 974 MCM to 223 MCM, thus meeting the demands of the North Central Province in respect of its needs for agriculture and domestic raw water.

As for catering to the needs of the water deficit in the Northern Province, since fresh infrastructure is needed in the Northern Province under either of the two options addressed above, what is proposed herein is to construct the needed infrastructure to harness the North-East Monsoonal rains to meet its agricultural and domestic needs, instead of transferring water from Randenigala which incidentally, is from the same North-East Monsoon.

Attempts to promote and advance this concept on the basis of its multiple benefits by way of cost and prudence among those who are intimately associated with the ongoing Upper Elahera Canal Project, and those who should be held accountable, have failed. In this regard, those who have been promoting the concept cited above are indeed heartened by the comments the President Ranil Wickramasinghe made during a discussion with Tamil Parliamentarians representing the North and East. He referred to the need to include River for Jaffna (bringing fresh water to Jaffna Lagoon, and increasing the capacity of Iranamadu Tank), the Small Tanks renewable program…” (The Daily News, July 19, 2023).

According to the seminal work of S. Arumugam which contains a wealth of information relating to past and present Irrigation in his book “Water Resources of Ceylon”, Iranamadu Kulam (82,000 ac.ft) “was the first tank to be constructed by the Irrigation Department”. However, Mr. Arumugam also refers to several ancient tanks whose antiquities are not known, such as Akkarayan Kulam (17,000 ac ft); Kalmadu Kulam (9,150 ac. ft); Muthu Iyan Kaddu Kulam (41,000 ac. ft); Thannimurippu Kulam 15,000 ac. ft) assigned to King Aggabodhi [575 -608], Furthermore, what is remarkable is the fact that the cumulative capacity of ONLY these 4 ancient tanks match the capacity of Iranamadu Kulam, demonstrating that that the practice of harnessing North-East Monsoonal rains to irrigate the North was clearly an ancient irrigation practice.

Since restoring these 4 ancient Kulams alone would double the existing storage capacity in the Northern Province, the focus should be to develop these tanks and other small Kulams, as planned by the President. Therefore, it is imperative that the President directs the appropriate Ministries and related Departments to abandon the idea of transferring water from Randenigala, and revise the scope and scale of the Upper Elehera Canal to be in keeping with what makes sense.