A Conversation with Dr. Tirusew Asefa

April 5, 2021
I had the pleasure of speaking with Dr. Tirusew Asefa, a Florida-based scientist and expert in water resource management about the GERD Negotiations, the Nile river, and much more. Our conversation follows below:

Eliezer Abate: Thanks for joining me today Dr. Tirusew. Before we get started, I would love for you to tell us a bit about yourself, what do you do and how long you have been working in hydrology and water resources management. I’ve noticed you’ve been advocating on issues related to the GERD for the past 18 months by hosting panels with international experts, tweeting actively, and publishing educational content on WeAspire?

Tirusew Asefa: My expertise is in general water resources management. My B.Sc. is in Irrigation Engineering (Arbaminch University), Masters in primarily in surface water/ groundwater (Belgium, by way of Catholic University of Leuven and Free University of Brussels) and my PhD on statistical learning (machine learning) from Utah State University.

Hydrology is always fascinating for me since we are chasing the water cycle (energy transfer in different ways): from rainfall, evapotranspiration, river flow, groundwater flow, and most importantly how water moves in this different states (conserving mass) and how it may change in the future and what we need to do to manage it effectively.

Currently, I oversee a highly technical team who are responsible for applied research and support in all areas of water resources management to provide water in one of the most dynamic metropolitan regions in the US, Tampa Bay. We supply water for over 2.5 million people today and plan out to 2040. I have a courtesy appointment at University of South Florida where I give seminars/class on different aspects of water resources management. I teach short (block course) at University of Tlemcen, Algeria under the Pan African University umbrella (I love it!) as well. 

When I still have time outside of this, I am also an active participant and part of a very dynamic group of professionals at WeAspire (I don’t know where they get their energy, but they keep me going as well).

Of course, about 18 months ago, the issue of GERD and specifically how the US and World Bank tried to arm-twist and get through a very unfair deal to Ethiopia brought my attention, which until that time I was following passively. Since then I am trying to do whatever I can to help. Specifically, because of my expertise, I am interested in educating the public about the scientific facts regarding the Nile basin and the GERD. There is a lot of misinformation out there that is not good for any of the countries in the Nile basin.

EA: Very fascinating and impressive background. Looking forward to picking your brain with some questions! Let’s get started:  What do you think is the single biggest obstacle to the three countries reaching an agreement on the GERD?

TA: The biggest problem is Egypt and Sudan are trying to use GERD, a single project, on a single tributary of the Nile, as a water sharing instrument. The water sharing being proposed is based on the 1959 colonial agreement that grants them 100% of the Nile’s waters and 0% for Ethiopia despite Ethiopia generating 86% of the total flow. 

You will hear this proposal framed in different languages in the press such as “historical rights”, “drought release” + binding release agreement, etc. But the bottom line is the unwavering effort by the two countries to impose a colonial agreement. Ethiopia wasn’t even part of it.

EA: That's certainly a combative approach on their part and I can see why it’s a non-starter for Ethiopia. Still, the Ethiopian team seems determined to solve the impasse through diplomacy and negotiation. Ethiopian Prime Minister Abiy Ahmed, said in a recent speech to parliament that Ethiopia is ready to sign a filling agreement today while kinks still need to be worked out on the operation side of things. Some commentators have mentioned that it might be wise to decouple the filling & operation into two separate agreements. Do you agree with this?  

TA: Yes. The only practical way that I see is to decouple the filling and operation of GERD. This is not just my opinion, but many experts as well agree that is the way to go, including the European Union. That is because the long-term operation of GERD is related to concerns around priority (i.e. which dams and whose dams on the Nile get refilled first) & how much water Ethiopia should use to fill its dam in case of drought and how much water to release etc ... 

If Ethiopia’s share of the Nile’s waters were known, Ethiopia could have simply used its share under any such scenarios without impacting others. Without such an agreement, which is where we are today, Egypt and Sudan are asking that Ethiopia receive ZERO share and saying we would be the first to use the water and you’ll get yours after our needs are satisfied. I think it’s fair for Ethiopia to say, “Hey, I am going to use my share (not more than that and not touching anyone’s) under such a scenario.” Unfortunately, Egypt and Sudan do not agree with that.

EA: How much total water is there to share in the Nile Basin? You’ve previously mentioned that there isn’t currently a proper accounting of the entire Nile water supply and have described a concept that you call the Nile Water Balance? Tell us a little more about this.

TA: Thanks for bringing this question up. I do believe this is the main issue in the Nile Basin today. It is still a question that needs to be answered. Several scientific studies/data show that the Nile River flow as measured at Aswan is already much more than the number that was used in the 1959 agreement of 84 billion cubic meters (BCM). In fact, it is more than 90 BCM based on just streamflow measurement. But that is not even close to the exact value because groundwater and surface water interaction is dynamic and has never yet been rigorously studied scientifically. 

The water you see at the downstream location in Egypt is impacted by loss of groundwater along the way because water from the Nile river goes into the ground, evaporates from both the water body and the ground (hydrologic cycle), and there is little accounting of this. It is like if you want to know what is in your bank account, you really need to account for every expense going out and income coming in. In a way, many of the expenses such as the groundwater withdrawal in Sudan that can directly impact Nile flow are unknown. A true water sharing scheme in the basin should need to look at both surface and groundwater. 

For this reason, I argue there is more water in the Nile basin than typically reported in the media and scientific papers that just look at surface water measurements. We need to have an Integrated Hydrologic Model to figure out the real value. As of right now, there is no such model in the Nile Basin. There is enough water in the basin, the issue is how best to use this resource efficiently and effectively through an integrated water resources management tool. 

EA: It seems to me that these negotiations are really putting the cart before the proverbial horse for the basin as a whole and for Ethiopia in particular. From what you have described, the order of operations should be a filling agreement first, then water allocation, and finally GERD operation agreement. The latter two will clearly take some time to flesh out and won’t be reached before the planned second filling this summer.

Yet Egypt and Sudan have successfully framed Ethiopia as the main obstacle to reaching an agreement. Now they are accusingly Ethiopia of attempting to “unilaterally” pursue the second filling without signing a binding agreement on the GERD. Why are they so focused on getting a binding agreement?  

TA: You hear in the media that Ethiopia is not agreeing to a binding agreement and Egypt and Sudan are. This is not a correct statement. I think they should ultimately sign a binding agreement that clearly delineates every country’s obligation on how much they should use from the Nile water. The issue is a binding agreement on the GERD means that certain releases to downstream countries MUST be honored at all times as they should. But how much water releases should be honored is the question. Egypt and Sudan are asking all water should go down forever, which results in a zero percent share for Ethiopia. Ethiopia finds this unacceptable and wants to share some of the water. As a country that produces 86% of the total flow, it is saying my share should be at least something more than 0%.

EA: That seems reasonable. How about in the event that there is a multi-year drought and both the GERD & Egypt’s High Aswan Dam (HAD) run low and require refilling: who goes first? Are discussions about second and subsequent fillings part of the current negotiations and do they address these concerns around priority?

TA: Yes, in a way. Some of these issues go back to the priority of filling the two main dams (and how much) during times of drought and the “binding agreement” which goes back to water allocation. Both Ethiopia and Egypt do not agree on both the quantity of releases as well as what that release should be permanently (meaning water sharing). 

The moment you agree on a certain release to be permanent, forever, it has an associated water sharing implication . It is OK to have a permanent agreement and I believe they should do that. The issue is that Egypt and Sudan want a 0% share for Ethiopia that is a nonstarter.

EA: Seems like we’re always circling back to water sharing. In a recent webinar, Mohamed Helal, a member of the Egyptian negotiating team shared the Trump administration's Washington DC proposal that you called arm-twisting earlier, for GERD water release scenarios under drought, prolonged drought, and prolonged dry years. 

Ethiopian negotiators walked out of the DC meeting saying that the US had put its thumb on the scale in Egypt’s favor and was trying to force Ethiopia to sign an agreement that would guarantee a 0% share. How do the “drought, prolonged drought, etc” arrangements factor into an equation that results in 0% water for Ethiopia? 

TA: The issue is that both Egypt and Sudan do not want to explicitly talk about water sharing but what they propose in terms of permanent release, aka, “binding release agreement” is in fact a water sharing scheme with 0% for Ethiopia. Typically, these are bundled in “drought release”, “extended drought release”, etc. 

For an average person it would look as though, hey what’s up with Ethiopia why don’t they want to help the two downstream countries? But the issue is what Egypt and Sudan are asking Ethiopia is to practically guarantee ALL the water there is today, for one. Second, even if mother nature changes its flow in the future, Ethiopia must deliver that in the future. According to this, Ethiopia needs to play God as well. Future drought should be shared by everyone equally. 

This puts Ethiopia in a place where it potentially needs to transfer water from other river basins just to conform to what they are asking. It is outrageous. How can you ask more water than that would be there if the dam was not there in the first place? It is like they are trying to punish Ethiopia for building a dam that has a clear benefit to Sudan and Egypt. Obviously, there are other reasons beyond hydrologic science that are beyond my expertise and pay grade.

EA: In what seems like an increasingly common talking point, the Egyptian Minister of Irrigation recently said that Ethiopia receives more than 900BCM of rainfall every year and that it's ridiculous for Ethiopia to demand a share of the Abay River’s mere 49BCM of water? Is a country’s rainfall a shared resource just like rivers that are transboundary? Also, from my understanding most of the rainfall either evaporates or goes into the rivers themselves. Is the Egyptian Minister of Irrigation correct?

TA: Arguing about the amount of rainfall that Ethiopia gets is simply an attempt to intentionally mislead those who don’t know hydrology 101. It's an uninformed opinion about science. I have seen in the past Egyptian arguments on virtual water (embedded in cattle’s) as well. The hydrologic cycle shows that most of the rainfall do not turn into runoff (river flow), the majority end up in evapotranspiration and some get through groundwater and flow to Sudan as well. The only way for Ethiopia to benefit from direct capture of rainfall (which is a crazy idea) is to build small scale hydropower generation or irrigation storage in every house or neighborhood, which makes no sense.  Some of the rain falls in areas you can’t practically access.Plus, rainfall variability in the Nile basin is such that you get 70% to 80% of the rain in just a few months. You would need to have enough storage to be used year-round. This cannot happen in people’s little backyard. You store river flow not rainfall. 

The idea that Ethiopia has x amount of rain and should forfeit its right to its river flow is simply nonsense and not based on the very science of hydrologic cycle. They know it. We know it. By the way the Nile basin constitutes 70% Ethiopia’s surface flow and it is important to use this resource. Other than this basin, we are pretty much limited.

EA: Thanks for the fact-check there! Professor Elfatih Eltahir of MIT has argued that the GERD by virtue of its location has brought the interests of Egypt, Sudan, and Ethiopia together. He argues that any consumptive use (i.e. irrigation) of water upstream of the GERD will not only reduce water to Sudan and Egypt but it will also reduce electricity generation in Ethiopia? 

First, do you agree with this assessment? And second, since Ethiopia’s objective will be to maximize electricity generation, how much water do you think Ethiopia can realistically draw from the Abay River (Blue Nile)? 

TA: Very loaded question.

I agree with Prof. Elthahir on all the facts. First, the right place to store water in the Nile Basin is in the Ethiopian highlands because you can store water cheaply (with very little loss to evaporation) and produce tremendous hydroelectric power because of the great topography. You need both flow and elevation for great hydropower generation. This will even become more important with climate change as more warming means more loss of water in Sudan and Egypt and more rainfall variability means you have the space to store in Ethiopia. 

I also agree with Prof. Elthahir that because GERD’s main objective is to get the maximum energy that can be produced, it is not in the interest of Ethiopia to spend US$5 billion and simply reduce the water upstream through excessive consumptive use. Power production and agricultural water use (or other consumptive use) will be competing. All this should be something Sudan and Egypt are cheering for. 

But along year-to-year variability of the flow, some years you are going to get significantly less water than average. What will the priority of dam filling be between HAD and GERD after a drought spell? That is why the country’s need to have their share identified ahead of time. If Ethiopia has its own share, during times of drought, it will simply use its share to fill GERD without impacting anyone else. 

In the absence of any agreement on water sharing, Egypt and Sudan are saying you must pass all the water downstream and if you are lucky and mother nature sends more water, you will be able to fill the dam and produce the electricity you need. Just like it is not fair for Ethiopia to hold significant amounts of the water during such times, it is not also fair for Egypt and Sudan to say all water should be theirs. 

Regarding the question of how much Ethiopia should claim as part of her share from the Abay River (Blue Nile)? I would just hold that one for now since the three countries are not discussing that. Talking about the amount of water sharing will be premature at the moment. When the time comes, I will have my opinion, obviously. I can tell you it is not 0%.

EA: Fair enough. Onto a technical question about the dam itself. What is the minimum water or height that the GERD needs to be filled at to generate electricity? Is there a risk that the dam’s electricity production will be reduced in drought years? Is this typical for most major hydro-electric dams in other parts of the world?

TA: Good question. GERD utilizes a smart design which allows its two turbines that are at lower levels to produce electricity while the filling continues. This corresponds to the 595 meter high or 18.4 BCM storage level. Therefore, I would say the minimum that it can go in the extreme situation is this level (I hope we don’t see this and the likelihood of this is almost zero as well because of flow and operational conditions). You would have to completely shut down many of the turbines to get to that. But theoretically speaking, I would say that is the minimum. I am not aware of this kind of drought in other places because hydropower production is managed proactively. It’s very rare, simply because of statistics of hydrology. 

EA: This level of 18.4 BCM is what will be reached after this summer’s filling of 13.5BCM following last year's first filling of 4.9BCM. Your answer also checks out with the Ethiopian government’s statements that it plans to generate electricity from the two turbines this summer. This summer’s filling is then crucial for Ethiopia as Ethiopians will start seeing the benefit of the dam within months of the filling. This is exciting news.

Onto concerns around the GERD's safety. Some in the press have brought up concerns about the safety of the GERD for Sudan. Do you think Sudan’s concern about dam safety or the GERD’s potential impact on Sudan’s smaller Roseriers Dam is justified?

TA: Dam safety from the perspective of complete failure is not justified and I do not think it is an issue anymore as far as the official Sudanese position is considered even though we sometimes hear reports in the media with no confirmation from the Sudanese authorities. GERD is structurally the safest dam that you can find on the Nile compared to downstream dams by any measure one would want to look at.

On the other hand, Sudan’s concern about data sharing is justified. Their dam is one tenth of GERD and a normal GERD summer operation could be challenging if there is no coordination regarding daily/weekly releases, etc. This should be easy to handle between the two countries. 

Daily/weekly/monthly operational coordination are not new in many parts of the world and should be handled by both countries. If both countries agree, there are all kinds of real time operational tools you can use (we call them Supervisory Control and Data Acquisition (SCADA) systems that  can be shared by all countries). Obviously, reciprocal data sharing is needed. Data flow should be both ways. That is how you build trust. 

EA: Are you optimistic about an agreement being reached? What will happen if the GERD filling is completed and the dam starts operating without an agreement? Some Ethiopian negotiators have said it's actually in the best interest of downstream countries to reach an agreement, even more so than Ethiopia? What’s your take?

TA: I am optimistic an agreement on the first filling of the dam will be reached since that is relatively easy. A lot of doom and gloom studies that were scaring the public a few years back regarding the supposed dramatic impact of GERD on downstream countries have turned out not to be true now and the public is aware of that. The Aswan High Dam is at a historical high level and based on current hydrologic conditions, there is no scientific reason to worry about shortage of water because of the GERD’s filling. 

There is enough water in the basin. In fact, lots of it. It is in the best interest of all three countries to have an initial filling agreement and then work on water sharing issues later so that expectations are set and equitable and reasonable water use is realized. The status quo of the two countries taking all the Nile’s water simply is not going to work. The only way to make that right is through honest dialogue. Cooperation and optimizing the resource the basin has is the only way to go ahead.

EA: Water-sharing rears its head again! We’ve touched on it enough, we'll move to another question: It’s well documented that Egypt’s High Aswan Dam loses 10 - 15 billion cubic meters of water annually from evaporation. Haggai Erlich, the Israeli historian, has called it the wrong dam in the wrong place. Do you think this is a reality that the three countries will have to live with over the next 50 to 100 years? Is this degree of evaporation a fact of life that the basin will have to put up with even though every country is scrambling to ensure their share of this already scarce resource?

TA: It is true the High Aswan Dam (HAD) has quite a bit of evaporation loss. It indeed is the wrong place from a purely water storage perspective. In fact, those numbers are when HAD was at a lower level. Currently, the loss is in the order of 16 to 17 BCM since the amount of water in its reservoir is at record high levels and evaporation increases as surface area increases. Even if we assume that the water sharing agreement is solved and Ethiopia has its own share, I am pretty sure in the future climate change and increased temperature will force Egyptians to store water in the Ethiopian highlands. 

EA: That would be quite the turn of events, from confrontation to cooperation! Let’s talk about alternative water resources in the basin. I want to bring up the case of Israel, which is a country that is having tremendous success with sea water desalination. Its desalination plants actually now provide more water than the country needs. Egypt has access to a 2900km coastline in addition to significant groundwater resources. Assuming investments are made in these areas, how much ‘new’ water could potentially be added to Egypt's water supply?

TA: How much more desalinated water Egypt could add to its water supply portfolio is limited by how cost effectively it can produce it. By the way, a well-balanced water resources management would have an all-of-the above approach (surface water, groundwater, recycled water, as well as desalinated water).

I work for a company that pioneered the construction of the largest desalinated sea water facility in North America. I have watched over the years the remarkably cheaper cost of using this technology. 

In terms of operation, the major cost is power consumption because you need to use a reverse osmosis technology to separate salt from water at high pressure using higher power. Looking ahead, Egypt should be able to increase its power production from solar power, for example, and it becomes a lot cheaper.

There is a big misconception in terms of the cost of the technology, it does not have to be direct sea water. You can also use brackish water (deeper aquifer salty water) at even a cheaper cost because you now use less power because of less salt concentration.

We in Florida, have quite a bit of this brackish water since we are circled on three sides by the ocean. So, it’s not just limited to the sea water. Yeah, so going forward, diversification of the water supply portfolio is good not just for Egypt but for every Nile Basin riparian country as well.

EA: These approaches sound like they would require cooperation across the Nile Basin countries to achieve optimal results for everyone. Ethiopian negotiators seem fairly confident that Egypt will sooner or later join the Cooperative Framework Agreement (CFA) to develop the Nile’s resources under a multilateral commission. Ethiopia, Kenya, Uganda, Rwanda, Tanzania, and Burundi are signatories and Egypt and Sudan were strongly opposed to the CFA at the time. Do you think they will eventually come around?

TA: I think so. We also just heard in the media that South Sudan will ratify the CFA. That is the only way to manage a transboundary shared water resource. Every scientific study that has looked at basin level economic and water management scenarios will tell you that a unilateral decision simply would result in a suboptimal solution. Given the limitations of the Nile water resources compared to demand in the future, this will undoubtedly result in conflict. Figuring out a win-win solution through a mechanism like the CFA is probably the only way to go forward.

EA: At the root of all these issues is a lack of trust between the three parties. Egypt and Sudan have burned goodwill in the past by signing bilateral agreements like the 1959 agreement which allocated themselves the entire water supply of the Nile & as well as frustrate Ethiopia’s efforts to develop by diplomatically working to block funds from the IMF and World Bank. How can these countries overcome the trust barrier? 

TA: For one, recognize other riparian states water sharing right as well. It has been said a lot about the 1959 agreement you mentioned. I would simply ask people to just look at the title of that agreement, it will tell you all you need to know about it. It says: “Agreement for the full utilization of the Nile waters...” How two countries can impose “full” utilization of water when 100% is produced by other riparian states is beyond me. It is not fair, not equitable and most importantly not sustainable.  Breaking the impasse means recognizing others' right to use the water resources. Especially Ethiopia who generates 86% of the flow. The status quo simply is not going to work.

EA: So we end where we started, underscoring the need for Egypt and Sudan to acknowledge Ethiopia’s right to a share of the Nile river of which it provides 86% of the water. Thank you so much Dr. Tirusew for joining me today and sharing your knowledge. This has certainly enriched my understanding of the issues around the GERD negotiations and I hope it will that of other readers as well.

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