Inside tale of how Isimba came apart at the seams

An aerial view of Isimba hydro power dam still under construction in Kayunga District on June 21, 2018. PHOTO / FILE

What you need to know:

  • Insiders say red flags had long shot up about the procurement of construction materials, which were, for the most part, treated causally, with action only happening after anomalies started to stick out like a sore thumb in the final construction outcome.

When President Museveni rose to deliver his keynote address while commissioning the 183MW Isimba Hydropower Plant, he was generous with his praises for the Chinese government and its people.

Mr Museveni described the government and people of China as reliable partners of Uganda.

Earlier, Mr Badru Kiggundu—the chairperson of the steering committee for the Isimba and Karuma hydropower dams—had held that the former was primed to boost Uganda’s economic prosperity.

“Another 183MW added to our power generation capacity is a great achievement and calls for us to remain steadfast in expanding the base for productive use of electricity such as value-addition to agricultural products through agro-processing and setting up more manufacturing factories,” Mr Kiggundu said.

The government awarded a Chinese firm—China International Water & Electric Corporation (CIWE)—the contract for the $567.7m (about Shs2.2 trillion) Isimba project. The project started in April 2015, and was commissioned in March 2019.

It was expected to generate an annual 1,039GWh (gigawatt hours) of electricity once it reached a substantial completion mark on March 31, 2019.

Upon commissioning, the installed electricity capacity in the country grew to more than 1,000 megawatts with the launch. The consequential feat compelled the government to predict that it could prompt tariff reduction for large-scale consumers supplied from the national grid.

On his part, President Museveni continued to crow about the facility that lies some 67 kilometres northeast of Kampala in Kayunga District. Three years later, however, the plant appears to be coming apart at the seams.

Insiders have told Saturday Monitor that red flags had long shot up about the procurement of construction materials. They were for the most part treated causally, with action only happening after anomalies started to stick out like a sore thumb in the final construction outcome.

We have also been told about infighting, as well as conflicts of interest between the Owner’s Engineer (the project supervisor on behalf of the government) Energy Infratech PVT Limited (EIPL), and the project contractor (CIWE) that would later impact the project.

All of this has left the Uganda Electricity Generation Company Limited (UEGCL) on the back foot as it sets out to fix and restore one of the four-generation units of the plant.

According to inside sources, Unit 3 (turbine) of the dam has been kept out of action right from day one of the plant’s life. This has been principally down to engineering errors and shoddy works done on it by the contractor.

Unit 3 debacle

The Energy ministry had maintained that Isimba Dam was boosting the national grid with an additional 183MW until the plant was shut down early last month due to a technical breakdown.

UEGCL has maintained that Unit 3 of the plant remains on scheduled outage (i.e. down and pending restoration). Its acknowledgement of the outage of Unit 3 lends credence to what internal sources told Saturday Monitor.

Our sources insist Unit 3 has never functioned since the first flood incident struck the plant in 2019. This was before the contractor handed over the plant to the government.

On August 22, following an emergency shutdown, UEGCL confirmed its team of operations and maintenance (O&M) engineers successfully synchronised the third unit (Unit 1) at the Isimba hydropower plant onto the national grid. The synchronisation, they added, meant that the Isimba dam was fully restored to normal generation, producing 137MW as opposed to a government claim of 183MW.

A former supervisor (engineer) during the construction of the plant—who has since been reassigned to another plant—told Saturday Monitor that the unit is out of action due to technical defects that resulted from the “deliberate acts” of the contractor.

“On the third generating unit (turbine 3) of the plant, what exactly happened to it was that the contractor did not fix it correctly,” the former supervisor, who asked to remain anonymous, said, before listing a litany of errors. “One, the wiring was just too bad; two, some of the electromechanical components did not match.”

According to the former supervisor, the unit was fixed at a time when there was no substantial owner’s engineer to supervise its installation.

“It caused a lot of tension between UEGCL and the contractor, but somehow the two parties agreed that the completion certificate is issued to allow timely commissioning even if it is not in order while the contractor works towards fixing it during the defects liability period,” our source added. 

Defects galore

A March 31, 2019, takeover certificate was issued to the engineering, procurement, and construction (EPC) contractor on April 12, 2019. It came along with a list of 775 documented snags and an outstanding scope of work. The defects liability period (DLP) was extended for one year from April 1, 2021, to March 31, 2022.

Mr Harrison Mutikanga, UEGCL’s chief executive officer, affirmed that the rough edges would be smoothed out during the period. Upon completion, a certificate of completion would be issued.

“Whether they have completed the outstanding scopes, like the log boom, if they have completed, we will go ahead and issue a certificate of completion,” he said then.

Mr Mutikanga was dismayed that the contractor (CIWE) had not done a good job with some of the defects.

“You have seen we now have three units running instead of four; one unit is down because the generator circuit breaker is not working. You have seen we have concrete leakages in the powerhouse; they are currently trying to fix all these defects,” he said, barely hiding his frustration.

He added: “There have been a lot of delays, we have had a lot of quality challenges, and so they need to improve the quality assurance and quality control. We must make sure the project is completed properly and we can meet our debt obligations and also generate reliable electricity to foster economic development of the country.”

Another insider told us that the conflict over rectifying the defect in Unit 3 necessitated the involvement of Mr Museveni.

“Disagreements among the government (UEGCL), EIPL and CIWE started way back in early 2016 when the cracks and other defects started manifesting,” our source noted, adding, “This later caused the axing of EIPL in 2017 on grounds of inefficiency to maximally supervise CIWE progress.”

The insider proceeded to note that besides Unit 3, “the [water intake] gates have severe problems. Our source says “the concrete establishment has been disintegrating and serious cracks have been developing while parts of the concrete get washed away.” The insider referenced 2019 “when we experienced an accident at the plant during which we lost some senior marine divers.” The divers “were going to ascertain the extent of the damage in the gates from under the waters.”

Even after the government issued completion certificates to the contractor, once wet and dry tests of the unit were done with the unit as non-functioning, UEGCL was reportedly still apprehensive about taking over the plant as per another source.

 EIPL axing

In September 2017, the contract for Energy Infratech PVT Limited (EIPL) expired. This was Isimba Dam owner’s engineer. The government decided not to renew EIPL’s contract based on the contractual premise.

EIPL was hired by the government as its supervising consultant (owner’s engineer) for the Isimba Hydro Power Project. EIPL ceased to hold the docket on September 7, 2017, after a 40-month run from May 7, 2014, according to documents Saturday Monitor has seen.

Energy Minister Ruth Nankabirwa and other government officials tour the dam last month. Photo /Joseph Kiggundu

On September 7, 2017, Mr Kiggundu led a team of the project steering committee to officiate a handover from EIPL to UEGCL. This was purely as an interim measure before a new supervising consultant could be procured.

The team comprised representatives from the Finance and Energy ministries, as well as the Attorney General’s chambers. In one of the minutes of a high-level meeting held at the Energy ministry headquarters in Kampala, seen by Saturday Monitor, EIPL was accused of procuring and supervising the use of ‘fake’ construction materials.

A source at the Energy ministry described a blunder committed by EIPL around change of materials for electro-mechanical and hydro-mechanical equipment as not just telling but “deliberate.” The commission was at the time the turbine units were being assembled and fixed. “The project (EPC) contract and employer requirements specified the material properties for equipment like gates, draft tubes, stop logs, cooling system, etc. It was very frustrating that these were changed to materials of a lower or inferior grade compared to what was specified in the contract, under the watch of EIPL,” our source noted.

Errors of commission?

EIPL for a long period failed to mobilise experienced key supervision personnel, including quality control specialists, electromechanical specialists and experienced geotechnical engineers to substantively lead in the supervision of the construction of the embankment dams. This was despite repeated recommendations and calls to fill the agreed project supervision structure, part of the minutes say.

This compromised the construction control aspects, and in some instances led to non-conformances related to material placement and dam monitoring instrumentation for both the Left and Right Embankment Dams. Installation of dam monitoring equipment and construction for embankment dams is critical for dam safety on projects of this nature.

Under the contract, EIPL was mandated with providing professional services, personnel and technical resources appropriate for the supervision of the engineering, procurement and construction works done by the CIWE as per the EPC contract, specifications and international standards.

This involved review and approval of designs, construction method statements and construction drawings, supervision of construction works and approval of completed structures.

The supervision contract also included witnessing the testing of manufacturing equipment like gates, turbines, generators, transformers, draft tubes, governors, exciter, cooling systems and a whole lot of other associated electromechanical equipment.

Unyielding negotiations

The process of procuring a new owner’s engineer (Artelia Kkatt Consult Ltd), however, was not to be a fortnightly activity by UEGCL. But work on site could not be stopped. Consequently, the Isimba UEGCL team was, therefore, thrown right into the deep end as the project supervisor in the interim pending confirmation of a new owner’s engineer.

According to internal sources, this lasted more than half a year. Insiders intimated to Saturday Monitor that it was during this period that many defects, later discovered in the dam, developed.

Upon realising the development of multiple defects, the Energy ministry became desperate to engage the stakeholders in negotiation on fixing the same and ensuring quality assurance.

This newspaper has seen leaked copies of the minutes of a meeting on negotiations for an extension of time (addendum no.4) held with the Energy, Finance and Justice ministries, together with UEGCL, UETCL, the CWE, as well as Artelia Kkatt Consult Ltd.

The meetings—held on August 8 and 13, 2018—were attended by, among others, Mr Kiggundu, UEGCL’s Isaac Arinaitwe, Ministry of Energy’s James Banabe, as well as representatives of the owner’s engineer and the CWE. When these people took their seats in the boardroom at the Energy ministry headquarters, they set out to agree on how the contractor should fix the defects.

At the meetings, UEGCL (employer) demanded that the contractor must replace parts of the installations earlier agreed to, as well as submit no-cost change proposals for adoption and approval of the installed parts that were not per UEGCL’s requirements.

Materials good enough

CWE, however, argued that the installed parts were qualified for serving the intended purposes without requiring replacement. CWE added that since similar parts had been used for various major hydropower projects worldwide without encountering any defects, this testified to the quality of the material.

The contractor also told its employer that the replacement of trunnion pin parts poses a high risk to the project, and that the position earlier communicated in April 2017 (to cause replacement) had since been reviewed.

The meeting then considered the risk associated with replacement as advised by the contractor and agreed that the installed shaft/pin of the trunnion can be kept beside the contractor agreeing to provide an additional warranty for 20 years. It was also agreed that the contractor provides one set of stainless steel pins/shaft as spares for the trunnions for each of the gates (lower and upper).

Elsewhere, UEGCL also agreed to release, in the next Interim Payment Certificate (IPC), the money withheld subject to the contractor’s submission of all the agreed Change Orders. In addition, it was agreed that the (Engineering, Procurement, Construction, Commissioning) EPCC shall supply and install the online monitoring systems from ZHEFU Ltd for all four units.

Whereas the government demanded that the DLP for the dam (five years), turbine and generator (three years), and all other parts and equipment (two years) be extended, the contractor rejected this and insisted on the original contract (two years).

Sweeping changes

The meeting also negotiated and settled for a change in the system design of the cooling water system for the turbine and generator to reflect the changed system design.

It also wanted the change in the design from automatic Load Break Switch in the Isolated Phase Duct to isolating links to reflect the change in functionality.

We have also established that the meeting agreed that the contractor must change the material in the hoist piston rods for intake and spillways from stainless steel to carbon steel. The material in the wheels/rollers of gates and stop logs was also to make a similar switch.

It was also agreed that the material in the axle wheels/rollers of gates and stop logs be changed from stainless steel to carbon steel, and that the design of hydraulic units for operation of the radial gates reflect an increase in the number of hydraulic units to be changed.

Among other things to be changed were the design of hydraulic units for the operation of the intake gates to reflect the reduction in the number of hydraulic units.

In September 2021, while leading a team of Cabinet ministers through a tour of the plant, Mr Julius Wamala—a UEGCL board member—hinted at the lack of spare parts and defects continuing to hinder the operations of the facility.

Given the slow pace of correction of the pending snags and completion of the outstanding works and defects by the contractor, exacerbated by the Covid-19 pandemic, Mr Wamala stated that the DLP extension would end without the contractor completing the correction of critical snags.

Emergency rescue

Engineers have continued to question the structural credibility of several components of the dam, including the embankment—the large concrete wall barricading the reservoir—on which the spillway gates sit. It forms part of the 10-storey dam house that includes the powerhouse and offices.

The defective concrete spill/waterways, according to a UEGCL report, are among the 10 major catastrophic flaws categorised as “high risk.”

There is an imminent threat as the embankment at the dam could burst and lead to flooding as raised water could barrel across homesteads, leaving a trail of destruction.

Reports of experts have in no uncertain terms indicated that the contractor, while building the plant, deliberately used substandard materials.

For instance, one report points out that the contractor used concrete of inferior class in areas where it is likely to cause cavitation (voids) and scouring (wash-off or erosion of abutments).

Last week, the Engineers Registration Board conducted a fact-finding visit to the plant during which they red-flagged the crumbling waterway concrete which continues to extend to the embankment and the concrete underneath the dam was damaged.

On Monday, this newspaper reported that China is deploying top energy and engineering experts to assess firsthand the nature and extent of defects at Isimba. The contingent was expected in the country yesterday.

The working visit comes after a report of multiple errors with the plant, and investigations illuminating concerns about the quality of the engineering, procurement and construction (EPC) project largely bankrolled by China’s Export and Import (EXIM) Bank and built by CIWE.

Blame game

In one August assessment report, UEGCL flagged 10 major defects all categorised as “high risk.” One of the defects that must be urgently fixed is the crumbling foundation concrete at the waterway gates. Images taken by underwater cameras indicate that the foundation continues to fragment slowly towards the embankment—the large concrete barricade that holds the reservoir.

Other key defects include powerhouse concrete cracks and roof drainage, embankment dams, installation of floating boom, leakages in the powerhouse roof, power firefighting system automation, tail water systems, and cabling in the powerhouse and switchyard.

While the DLP is due to expire later this year, CIWE, which had remained reluctant to address the lingering defects until the recent flooding, blames both the Energy ministry and UEGCL for the mess.

Litany of problems

A fortnight ago, this newspaper’s attempts to dig into what occasioned Isimba’s abrupt shutdown pointed to recurrent human errors and system inadequacies. Sources who spoke to us said the young, impressionable O&M engineers, who essentially run the dam, do so with limited backing of experienced engineers.

Our sources also revealed that the set of engineers currently manning the plant is yet to brush up knowledge on critical maintenance strategies such as reactive maintenance (run to failure), preventive maintenance (based on machine run schedule) and condition-based maintenance.

A review of the UEGCL’s June 2021 Status Report revealed that the Isimba dam’s DLP has continuously been extended due to the various snags and defects that were detected after the dam was commissioned in March 2019.

Powerhouse concrete cracks and roof drainage, embankment dams, floating boom installation, leakages in powerhouse roof, power firefighting system automation, tail water systems, and cabling in the powerhouse and switchyard were among the major flaws.

Others included the absence of platforms to access spiral casing, Unit 3 oil leakage, standby generators, elevators and lifts to lower redial gates with defective hydraulic hoists. All these cause leakage of oil into the river.

Isimba Dam speaks out

The Isimba Dam spokesperson, Mr Enock Kusasira, told Saturday Monitor: “Unit 3 has no one specific problem. The contractor requested to undertake various works at the unit, which include, among other things, rectifying electrical cabling defects. For such works to be undertaken, the unit has to be shutdown. Therefore, Unit 3 is on a planned outage, which is going to be concluded within the next two weeks.’’

He said it is normal practice to shutdown units to undertake planned maintenance, adding, “During the ongoing liability period, the contract compels the employer to provide units for the contractor to undertake repairs. Therefore, this will be an ongoing process which is planned and communicated to UETCL, who grant such planned outages.  Hence, we expect after Unit 3 is returned to operation, the contractor will request for another unit. This step by step rectification of the defects is best practice, which balances power production and outages.”

On the issue of defects, Mr Kusasira said: “In terms of progress, we commend the contractor for having closed more than 490 out of 700 defects.”

 He added that the outstanding 200-plus defects are being addressed in a systematic manner, saying some of the defects are still being disputed by the contractor, but discussions are ongoing in order to resolve the issues.