- SLE operates Kumbalgamuwa Mini Hydropower Plant
- Reservoir operates below 100% capacity
- IESL warns of ‘catastrophic irrecoverable damage’
Allegations are being levelled against Sri Lanka Energies Ltd. (SLE), a subsidiary of the State-run Ceylon Electricity Board (CEB), for obstructing much-needed repairs at the Samanalawewa Reservoir – repairs which are needed to avoid a catastrophic disaster that could lead to the loss of lives and property, The Sunday Morning learns.
Speaking to The Sunday Morning, an engineer attached to the CEB who wished to remain anonymous alleged that top-level officials at SLE were not allowing repairs to be done at the Samanalawewa Reservoir.
“The leaks in the reservoir benefit SLE, which operates the mini hydro plant that is located downstream from the leak. If the leak is stopped, the mini hydro plant will have to shut down and SLE officials fear they will lose the profits they gain from the other private businesses attached to the operations of this mini hydro plant.”
According to SLE’s 2019 Annual Report, it operates the Kumbalgamuwa Mini Hydropower Plant. It is learnt that when the water levels in the Samanalawewa Reservoir had drastically reduced last year, officials from various interested State departments and private entities had consulted with the CEB and the Power and Energy Ministry to repair the leaks, noting that “an opportunity like this would not come again”.
One such official who had consulted on the process last year told The Sunday Morning that the danger had been highlighted at the time, as the risk of the dam bursting could adversely affect thousands of people who live in the downstream areas of the Udawalawe Reservoir and as far as Ambalantota.
Furthermore, officials claimed that SLE was planning to build another mini hydro plant at the location since when the leak increased, the energy generated also increased.
“When they postponed the repairs last year, we hoped that they would do them this year at least when the water levels reduce again, but they have postponed it to 2025. There is no explanation for the rationale behind that decision,” they alleged.
Meanwhile, the CEB engineer said that the Samanalawewa Reservoir was not currently operating at a 100% capacity, noting that it had the potential to do so if the leaks were to be repaired. “Even if the mini hydro plant closes, there is a greater economic benefit in running the Samanalawewa Power Plant at a 100% capacity.”
The Institution of Engineers, Sri Lanka (IESL) had submitted a report to the Government in October 2023 on the “urgent need to implement remedial measures on the Samanalawewa Reservoir”.
“The reservoir has been leaking ever since it was filled with water in 1992. In response to calls from professionals, the IESL makes this intervention by preparing this status report and making recommendations to the Government of Sri Lanka about the need for urgent actions to arrest the leak, primarily to ensure the safety of the reservoir, dam, the people, and property downstream,” states the report, as seen by The Sunday Morning.
The IESL has said that in August 2023 when the water level in the reservoir had reached its lowest recorded level of 425 m above Mean Sea Level (MSL), several sinkholes had been observed upstream of the dam, on the Walawe Left Bank. These sinkholes were in addition to the sinkholes that appeared in 2000, when the reservoir level dropped to 427 m above MSL.
“It is most likely there are more sinkholes and other major points of leakage that are not visible yet. Further, based on a study conducted by Dr. Jagath Gunatilake of the University of Peradeniya, it is suspected that the tunnel named ‘adit G’ – used as an access tunnel during the construction of the grout curtain – is also contributing to the leakage,” the report reads.
Highlighting the risks involved in such a situation, the IESL has said that bursts and slips occurring in weak sections of the right bank may potentially open the reservoir under the full water head and generate a flood surge which would cause “catastrophic irrecoverable damage on the entire downstream expanse, its humans, livestock, and property, starting from the Kaltota Irrigation Scheme, propagating towards the Udawalawe Reservoir, and ending up at Ambalantota, Walawe River estuary”.
Several attempts to contact SLE General Manager Nandika Pathirage and Samanalawewa Complex Chief Engineer Udaya Ambepitiya proved futile.
When contacted, CEB Chairman Nalinda Ilangakoon said that there was “no such story”.
“There is no such story that SLE is obstructing. It is a long story. There are a lot of scientific decisions and that will be done as a Government thing,” he said.