CP and North: Water availability
Posted on October 23rd, 2021

by Neville Ladduwahetty Courtesy The Island

A report in The Sunday Times of 17 October, 2021 states: US $243 million (around Rs. 48,600 million) has been earmarked for a 27-km tunnel, considered the longest in the country under the Upper Elahera Canal Project of the Mahaweli …. Under the overall project, a 98-km network of canals and tunnels are to take water from Moragahakanda to Mahakandarawa wewa….”

The report however, does not indicate what quantities of water are to be delivered. However, the report confirms that the quantities of water to be delivered are sufficient to reach Mahakandarawa wewa which is about 6 km north-east of Mihintale. If so, it must mean that parts of the North Central Province (NCP) and Northern Province (NP) beyond the vicinity of Anuradhapura would not be receiving water from Moragahakanda.

This article attempts to analyze the data in two reports by Consultants to ascertain the capacity of the Upper Elahera Canal Project to deliver water to the NCP and NP. Since the focus of the report in the Sunday Times was on bypassing protocol”, the answers to the above questions should be the responsibility of those who designed the network of canals and tunnels to furnish the answers. In the absence of such information, an analysis of water availability under two conditions is presented herein in a form different to the one that was presented in an article titled Policies call for coordination in power sector” (The Island, October 12, 2021). The first was water availability when the network of canals and tunnels under construction is completed, and the second is upon the completion of the infrastructure needed to transfer water from Randenigala to the Kalu Ganga and through the latter to Moragahakanda and the Upper Elahera Canal.

TRANSFER of WATER to the NCP & NP

CONDITION ONE – WHEN CONSTRUCTION of NETWORK of CANALS and TUNNELS is COMPLETED

The Report prepared for the Ministry of Irrigation and Water Resources Management, dated December 2014 by Technical Assistance Consultants on behalf of the ADB, in Paragraph 21 (p. 343) states: The study has shown an increase in the diversion capacity at Moragahakanda to 974 MCM annually, required for the Upper Elahera Canal (UEC) and NCP canals addition to 617 MCM to the Minneriya Yoda Ela. The supplemental diversions from Kalu Ganga (772 MCM) Bowatenna (496 MCM) reservoirs and its own watershed (344 MCM) are adequate to cater the water demands under UEC.”

According to the data cited above, the ONLY sources of water available PRIOR TO CONSTRUCTING the infrastructure needed to transfer water from Randenigala to Kalu Ganga and eventually to Moragahakanda, is from Bowatenne 496 MCM, and water in its own catchments amounting to 344 MCM: a total of 840 MCM. When the waters needed by the five ancient five tanks are deducted i.e., 617 MCM, the balance available to be diverted to the UEC is 223 MCM.

An independent study carried out by SMEC International (Pvt) Ltd for the World Bank titled Updated Mahaweli Water Resources Development Plan”, dated November 2013 states in Appendix 5 Table 5.1, p.9 that the Downstream Release from Bowatenne is 651 MCM, the catchment inflow into Moragahakanda is 313 MCM, making a total inflow of 964 MCM. From this inflow, since 573 MCM has to be diverted to the ancient five tanks, the amount of water available for the UEC is 391 MCM.

Therefore, according to the data in the two reports, the quantity of water available to be transferred to the UEC when the network of canals and tunnels is completed is ONLY 223 MCM or 391 MCM, respectively. This water availability is in the range of the demands of Mannakkattiya-Eruwewa-Mahakandarawa (155 MCM) and Huruluwewa (126 MCM), making a total of 281 MCM according to paragraph 151 in the Report titled Environment Impact Assessment Report” prepared for the Ministry of Irrigation and Water Resources Management” by the Mahaweli Consultancy Bureau (Pvt) Ltd. Since these three tanks are in the vicinity of Anuradhapura it could be concluded that under Condition One, it is realistically not possible to divert water beyond Anuradhapura. Furthermore, since the water available for transfer from Moragahakanda is in the range of 300 MCM, the network of canals and tunnels under construction would be under-utilized, on the basis that they were designed to carry 974 MCM or 964 MCM of water cited in the two reports.

This conclusion is subject to 496 MCM or 651 MCM quoted in the two reports being transferred to Moragahakanda from Bowatanne. This may not be the case if water from Bowatenne to Moragahakanda is curtailed in order to divert more water from Bowatenne to meet the demands of North Western Province. Thus, the network of canals and tunnels under construction would be further under-utilized.

Under the circumstances, where no infrastructure exists to bring more water to Moragahakanda, the conclusion objectively reached from the analysis of data in both reports is that the quantities of water available are NOT sufficient to meet the demands of the NCP and the NP beyond Anuradhapura.

CONDITION TWO – TRANSFER of WATER from RANDENIGALA

In order increase water availability beyond Anuradhapura, the proposal is to transfer water from Randenigala augmented by water from Hasalaka Oya and Heen Ganga along the way together with water in 128 sq. km of the Kalu Ganga catchment (say76 MCM). Since the water demands in these two small tanks are 75 and 56 MCM respectively, Randenigala would need to divert 772MCM less (76+75+56) which is 565 MCM annually. Diverting 565 MCM of water from Randenigala, which is equal to the active capacity of the reservoir would have a serious impact not only on power generation at Randenigala but also on the amount of water available for diversion to the right and left banks of the Mahaweli at Minipe. Therefore, diverting water to Moragahakanda from Randenigala should be reconsidered. Diverting water to the NCP and NP at the expense of power generation and water availability to the East of Sri Lanka is a clear instance of contradictory policies that have been actively pursued by successive governments.

MAHAWELI DEVELOPMENT MASTER PLAN

According to the Mahaweli Development Authority’s Master Plan, In 1961 the government of Ceylon requested assistance from the special fund of the united nations to survey the Mahaweli Ganga Basin and the Dry Zone areas in the North and Central Provinces…. The plan of operation was drawn up and signed on 12 October, 1964 on behalf of the government of Ceylon, the United Nations Special fund and the food and agriculture organization of the united nations acting as executing agency. The co-operating government agency was the ministry of land, irrigation and power”.

The project was designed to achieve the following objectives:”

• To provide basic information on the land and water resources of the Mahaweli Ganga Basin and the Dry Zone areas of the North Central Provinces;

• To provide an overall water management plan with a view to the effective use of water for irrigation and power generation;

• To provide technical plans, preliminary design of works, cost estimates, priorities, phasing and financing needed for implementation of the plan” (Master Plan).

The project area covers 39 percent of the whole island and 55 percent of the Dry Zone. It includes the Mahaweli Ganga basin, the basin of the Maduru Oya and rivers in the north central part of the island”.

IT IS THUS EVIDENT THAT THE OBJECTIVE of the ORIGINAL MASTER PLAN was to IRRIGATE THE DRY ZONE AREAS of the NORTH CENTRAL PROVINCE. FURTHERMORE, that the PROJECT AREA was to be MAHAWELI GANGA BASIN and the BASIN of the MADURU OYA.

IMPACT of DECISIONS

What is evident from the network of canals and tunnels under construction as part of the UEC is the assumption that someday sufficient water would be transferred from Randenigala to the NCP and beyond to the NP. Having made such an irrevocable decision, it appears that every prospect is being explored to make it work regardless of consequences to power generation, to agriculture on the left bank of the Mahaweli at Minipe and interests in the Maduru Oya Basin. The folly of transferring water from Randenigala is compounded by developing the Upper and Lower Uma Oya schemes to augment the loss of water at Randenigala and at Minipe. However, notwithstanding such augmentation, nearly 300 MCM from Randenigala would yet be needed to meet the demands on the UEC.

It is only an attitude of come what may water would be delivered beyond the NCP to the NP, that would justify the scale of over design in the construction undertaken and currently underway. This is clearly evident from the fact that although the catchment of Kalu Ganga is only 128 sq. km (76 MCM), the newly constructed reservoir with a storage capacity of 265 MCM is several times larger than its catchment.

CONCLUSION

The design of the network of canals and tunnels under construction have clearly been influenced by the comments in the Reports, e.g., an increase in the diversion capacity at Moragahakanda to 974 MCM annually, required for the UEC and NCP canals” is available. The fact that this depends on The supplemental diversion from Kalu Ganga of 772 MCM and 496 MCM from Bowatenne is taken for granted as an irrefutable fact, notwithstanding its inherent consequences. The approach adopted reflects an attitude that an irrevocable decision has been taken to divert Mahaweli waters, no matter the costs to power generation at Randenigala and agricultural interests on the left bank of the Mahaweli at Minipe as well as in the Maduru Oya basin.

The pertinent question that needs to be asked is: Who is accountable for such an irrevocable decision when the decision has implications that go far beyond the scope outlined in the Master Plan of the Mahaweli Authority? The project area envisaged in the Master Plan was to cover 39 percent of the whole island and 55 percent of the Dry Zone. It includes the Mahaweli Ganga basin, the basin of the Maduru Oya and rivers in the north central part of the island”. Had the scope of the UEC been limited to the recommendations in the Master Plan, the cost of the network of canals and tunnels including the Kalu Ganga Reservoir would have been considerably less. The extra cost is because what is being constructed is to transfer 974 MCM on the presumption that 565 MCM would be transferred from Randenigala.

It is a matter of urgent necessity that sanity prevails and the scope of the UEC and all issues associated with it are reviewed without delay. Furthermore, since the technical fraternity has been silent on this issue thus far, it should be their responsibility to bring matters associated with the UEC to the attention of the political establishment. It would be a shameful indictment on all concerned if corrective measures are adopted only after the farmers in the Mahaweli and Maduru Oya basins starting from Minipe raise serious objections to the transfer of water from Randenigaka to the UEC.

Neville Ladduwahetty

October 22, 2021.

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