A twenty-one month comparative analysis of the progress in the construction of the GERD

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By Bereket Gebru – Oct. 30, 2014

Anyone who gets a chance to visit the Grand Ethiopian Renaissance Dam (GERD) is envied by everyone around them. Even those who have travelled well across the country and around the world long for the chance to pay a visit to the project that symbolizes the prosperous future that awaits Ethiopia. Considering the high excitement and anticipation all Ethiopians have associated with the dam, their longings are all understandable and positive in intent.

It was twenty-one months ago that I first got the chance to visit what is set to be the biggest dam in Africa. As expected, my friends tried to contact me and give them an account of the progress in construction while I was still there visiting. I did the best I could to give them a sense of what it is like to be there and supplemented that with pictures when I got back. What I understood at the time was that I would have asked for the same thing from someone who had been there, had I not got the chance. So, I wrote an article entitled “Hope in the making” incorporating a comprehensive account of the tremendous work I witnessed a sling shot away from the Ethio-Sudanese border.

I am now very glad I wrote that article because it has led the way for me to get back to the GERD project site. Twenty-one months on, I have been given a chance to be part of a team put together to report on the progress of the construction of the dam. My previous article on my then visit played a pivotal role in my nomination for the assignment.

As can be expected, my friends were almost pissed that I got a second chance to report on the project before they could see it even once. But in all fairness, one of the major requites of working in the media is the presence of opportunities to report on some of the most fascinating and highly regarded stories. Although this obviously comes as an issue they would also like to witness, I also have aspects of their jobs that I would love to experience.

With that in mind, I have prepared this article for all those out there who have not come across the chance to witness the progress in the construction of the GERD. To give a clear picture of how far along the project has come in the last twenty-one months, I have used comparative analysis of some aspects of the construction process.

To give a clear picture of the vast activities being carried out by the project, I have classified activities into groups and reported on the changes over the time gap between my two visits. When I first went to the project site, all there was to see of what is to become the foundation of the dam was a small rectangular sample of small height with the rest of the area going through some serious digging and explosion. There were frequent dynamite explosions with numerous boring machines and dump trucks swarming the area. At the time, engineers working on the project told us that all efforts were geared towards reaching at the bedrock on which the foundation would be laid.

Nowadays, the area that was marred with explosions and digging is occupied by two sets of huge structures on the left and right side of the river. According to the briefing we had, the explosion and digging sections of the project are nearly over with only two to three months of it remaining. The structures on either side of the river make up the foundation of the dam.

Foundation of the RCC GERD dam

The bigger of the two structures located on the right bank of the river harbors ten huge stair like bodies that would be used to bury penstocks. These structures make up the ten protruding sections on the famous GERD plan. Not noticeable from the back of the dam where administrative offices are located, the top of the dam spanning quite a number of football fields comes as a surprise for someone going on top of it for the first time.

Getting on top of the huge structure on the right of the river, one comes across teams of humans and machines piling on the Roller Compacted Concrete (RCC) from which the dam is made. Activities taking place here build on the height of the dam and human accounts of the activities claim that visible changes are evident on a daily basis. Considering the technique use to construct the dam does not involve iron reinforcements, piling on batches of RCC held together by bidding mortar is said to take a much shorter time. Moreover, the fact that the dam’s width goes narrower from 125m at the foundation to just 8m at its peak means its construction speed would pick up momentum as its height goes up.

Another feature of the top of the dam’s right section are the inspection galleries. Located at the upstream, middle and downstream sections of the dam are three tunnels running from the right end of the dam all the way to the back of the dam where the power houses are being built. These three tunnels are used for monitoring the dam and correspond to the dam’s three zonings that have different mixes.

Yet another of the structures being built on the right bank of the river is the power house for that side of the dam. Expected to be fitted with two of the ten generators set for that side of the dam this year, the power house is tipped to be able to produce 108 MW of electricity in less than a year. The start of production of electricity from the dam would no doubt be a huge milestone in the whole process of realizing the project and it is exciting to know that we might be just under a year away from it.

Going on to the left side of the river’s bank, various activities have also taken place within the twenty-one months it took me to get another chance to visit the project. On my first visit, there was a big hype about diverting the course of the Blue Nile within the near future and how it would be a significant step in building the dam. This time it has been quite a long time since that has been accomplished and the fuss has shifted to yet another diversion – diverting the river to its natural course.

With the diversion of the river to a new course set artificially, what used to be the river’s bed has gone dry making it easy for the builders to carry out their activities. Accordingly, various diggings and explosions have taken place on the former river bed to get to the bed rock up on which the foundation of the dam is situated. The six protruding structures depicted on the dam’s plan which are used to bury penstocks are being built on this side of the dam.

The other noticeable structure on this side of the dam includes the four box culverts fitted to its upstream end. These box culverts are gateways fitted at the front end of tunnels running across the width of the dam’s left side. Once the construction of this side of the dam gets to a certain point, the re-diversion of the Blue Nile to its natural course would follow in order to make room for construction activities that would connect the two sides of the dam which are presently separated by the river’s adopted artificial course. As has been pointed out above though, the dam has been erected on the river’s natural course. That is when the box culverts would come in handy by allowing the river to go through them and maintain its flow.

Saddle dam

Another one of the structures in the project to be included in my observational accounts is the Saddle dam – a 5.2 km long, 50m high and 17.2 million m³ volume rock filled dam being built to close the only route of escape for water to be accumulated by the GERD. During my previous visit, the location was marred with long and deep stretches of digging accompanied by a heavy traffic of the machineries transporting the huge amount of soil and rock.

This time around, I was pleasantly surprised to see that the dam is gaining height over the surrounding land especially at its right end. On its left end, a modern approach is being implemented. This modern approach is called curtail grouting and it has been used at Gilgel Gibe I in Ethiopia. The technique as applied at the GERD involves 80cm wide dig to the bed rock that would be filled with a plastic diaphragm wall to prevent water from penetrating through. According to Engineer Semegnew Bekele, the project manager, one million m³ of the 5.7 million m³ rock and soil needed to complete the Saddle dam foundation has already been filled. The Saddle dam is also fitted with emergency spill way. The overall change in the construction of the Saddle dam within the twenty-one month gap was impressive.

The power transmission line from Beles

Yet another one of the changes I observed was the new power transmission line at the project site crossing over the mountains nearby. The Grand Ethiopian Renaissance Dam project has been using diesel generators ever since its onset. However, their remaining days seem to be numbered as the giant power transmission lines hovering over them clearly indicate.

We were briefed that the huge power lines are part of the 240km 400kv power transmission line drawn from Beles. The 400kv capacity of the lines is also proof of the tremendous advancements in the carrying capacity of the power transmission lines in our country. Those lines would help replace the diesel generators at the project site by bringing electric energy from Beles while upon the generation of electricity by the GERD, the same lines would be used to transmit electricity out of the hydro-electric power project.

The 500 kv power transmission line

Although not part of the project site at Guba, the 500kv power transmission line extension project spanning nearly 600km including cities like Dedessa and Holeta is also part of the GERD project aimed at transmitting the power generated by the GERD to various parts of the country and other neighboring countries. The two power transmission lines stated above obviously mark the dawn of a better day for electric energy transmission in Ethiopia as they enable the country transmit energy over long distance to our neighbors without energy wastage.

Housing

Still another section of the changes I have observed during my recent trip to the GERD project has to do with housing. The last twenty-one months saw the construction of numerous housing and service provision units at the project site by the Metal and Engineering Corporation (Metec). With various sorts of designs accommodating different forms of services, the houses cater to the needs of the vastly increasing number of workers at the site. Equipped with Air Conditioners, ventilators and toilets with showers the houses are cozy homes providing relief from the suffocating heat of Guba’s harsh outdoors. The fact that the houses have malaria nets fitted to their beds also helps protect workers from malaria infections.

With the lowland vicinities of Guba characterized by suffocating heat and threats of malaria infection for most of the year, activities to identify and develop alternative settlement spots for those who would take the responsibility of running the dam once its construction is over have been underway.

Accordingly, ten kilometers away from the construction site of the dam at Guba, a site on the adjoining mountains has been identified and numerous housing and service provision units have already been built with more along the way. Situated at the top of a huge mountain overlooking the project site and the future dam along with a section of the lake to be formed in front of it, the permanent housing site is immensely picturesque. Rising up to 1500m above sea level, according to experts working on the project, the mountainous permanent housing curbs the suffocating heat and malaria threats of the Guba valley which is located just 500m above sea level. With these facilities in place, those who would operate the Grand Ethiopian Renaissance Dam once it starts functioning fully would live under better conditions.

Tree clearing activities

In a bid to make the future reservoir free from trees that might have a toxic effect on the water, a vast tree clearing activity has been carried out between the time gap of my two visits. According to Semegnew Bekele, project manager, the Metal and Engineering Corporation (Metec) took on the project under whose sub-contracting schemes were involved various micro and small enterprises that mustered over thirty thousand workers. The efforts of such a huge work force are evident a long way from the project area as we saw fields and mountains as far as eighty kilometers away stripped of their tree cover on the Asosa-Guba road.

Resettlement

Engineer Semegnew Bekele stated that the environmental and social impact assessment researches have indicated a sparsely populated settlement in what would become the reservoir in front of the dam. He further explained that the Resettlement Action Plan (RAP) of the GERD project was discussed with local authorities and local residents.

The resettlement activities would settle people into villages and provide them with various social services they have been deprived of. Accordingly, settlers would be provided with electricity, schools, health facilities, clean water and other social services. The result of discussions with local authorities and residents, according to Engineer Semegnew, were positive as they have understood the developmental package the resettlement is accompanied by.

Other major changes

In addition to the above stated bundle of activities, there have also been other major changes with significant implications on the project and even the country as a whole. These major changes include:

Work force and machineries

Twenty-one months ago, Engineer Semegnew Bekele told us that there were about 5,000 employees with more than 1,200 machineries operating on the project site. This time around, he stated that there are about 9,000 workers including 400 expatriates. He further explained that the number of expats has gone down now that the 400 kv power transmission line work from Beles has been completed. Regarding the machineries, he pointed out that there currently are 2,300 of them operating on the project.

Local capacity building

While briefing us on various issues related to the construction of the dam, Engineer Semegnew duly noted that cost-reduction is at the centre of the construction activities. He further explained that cost–reduction entails building on the capacity of local construction and industrial establishments to produce imported materials locally.

One of the most notable import substitution successes achieved over the past twenty-one months has been the production of the formerly imported low heat of hydration cement locally. In addition to the two other types of cement used, low heat of hydration cement is currently being produced and supplied to the project by Mesebo and Derba cement factories – Ethiopian cement factories. The quality of cement produced in these factories is once again checked at the project’s laboratory upon arrival prior to its use in the construction process.

The other major capacity building success has to do with the box culverts. The box culverts used in other Ethiopian dams have always been supplied by foreign companies but the GERD has changed that reality as the Ethiopian Metals and Engineering Corporation (Metec) has produced those at the left end of the dam.

In addition to the above stated milestones in national capacity building, the GERD project has immensely pushed up the capacities of local engineers. By creating awareness and familiarizing local engineers with state of the art technological methods such as curtail grouting and roller compact concrete (RCC) building, the project is contributing a lot towards human development. As the project also accepts university fresh graduates from all over the country on apprenticeship basis, its contribution as a technological gallery and knowledge transmission platform is tremendous.

As the project has also created the necessity for the construction of roads and other business establishments, the capacity of local contractors has hugely been affected positively by the dam project. The increased activity along towns on the way to the GERD has also helped build the capacity of various business establishments. With time passing by, the GERD has increasingly realized its potential as a great capacity building tool.

Conclusion

As I have tried to depict above, there have been significant progresses made within the twenty-one months time between my two visits to the GERD. Some of these changes could have separately been taken as huge project undertakings on their own, had they not been part of the Grand Ethiopian Renaissance Dam (GERD) project.

The already completed work on the 240km long 400kv power transmission line from Beles is one of such significant undertakings which could have been taken as a huge project on its own. The work on the 500kv power transmission line is another. The housing units built by the Ethiopian Metal and Engineering Corporation and the permanent housing on the mountains nearby being built by Salini can also be cited.

Finally, I would like to remind others who have read this article to come up with their own accounts of the progress they have witnessed on the GERD. As clearly put by Engineer Semegnew Bekele, “it is the project of the people.” He also noted that visitors to the project site are warmly welcomed as they help raise workers’ morale with their genuine concern and appreciation for the project and those involved besides helping express the grandeur and significance of the project to their fellow Ethiopians up on their return. Therefore, I say let’s report on the progress for all those who have got the chance to visit the project that has marked Ethiopia on the international arena. For all those who have not yet got the chance, I hope it comes soon enough.

Sourced here  http://aigaforum.com/articles/GERD-round-two.php