Addis Abeba — Tirusew Asefa (PhD) is one of the few Ethiopian scholars recognized globally in the field of water resource management. With a master's degree in surface and groundwater studies and a PhD in statistical learning, Tirusew currently leads the Decision Support Group at Tampa Bay Water, the largest wholesale water supplier in the Southeastern United States.
Beyond his permanent position, Tirusew is frequently invited to serve as an independent evaluator and advisor for various projects in the US and Ethiopia. For the past three years, he and a team of professionals have been actively working to raise public awareness about Addis Abeba's water crisis. In January 2024, they authored a comprehensive policy paper explaining why addressing the existing chronic water supply in the city needs urgent attention.
During his recent visit to Ethiopia, Tirusew met with officials from the Ministry of Water and Energy and the Africa Center of Excellence for Water Management at Addis Abeba University. The discussions focused on the core constraints contributing to the water scarcity in the capital and potential solutions.
"Our discussions with stakeholders have been encouraging, but time will tell if this translates into concrete action," he remarked during a recent interview with Addis Standard's Molla Mitiku.
Tirusew emphasized that Addis Abeba's heavy reliance on groundwater is a significant concern that could exacerbate the city's already troubled water supply. "While groundwater has historically been beneficial for Addis Abeba, overdependence has led to the depletion of many aquifers," he explained.
To address the water crisis facing the residents of Addis Abeba, Tirusew advocates for the establishment of a comprehensive surface water system, including storage, treatment, and transmission infrastructure.
Excerpts from the interview follow.
AS: In your expert opinion, what are the primary factors contributing to water scarcity in Addis Abeba?
Tirusew: Before addressing the specific situation in Addis Abeba, it's important to recognize that many major cities worldwide face similar challenges as they develop. As their economies grow, cities attract more residents, putting a strain on resources.
In the past, water delivery was simpler, often involving a single-yard pipe serving multiple households. However, the current landscape, with a mix of condominiums, apartments, and single-family homes, has increased water consumption per capita significantly compared to 30-40 years ago.
This shift in housing types, dominated by modern residences in Addis Abeba for over a decade, is a key driver of the city's growing water demands. While population growth is a significant factor, the increase in individual water consumption also plays a crucial role.
AS: How much does water demand currently outpace supply in the city, and what are the future projections?
Tirusew: While the exact population of Addis Abeba is debated, it is clear that the current water supply falls significantly short of demand.
Water rationing is intensifying, and our estimates suggest that the city can only meet 40% of its water needs. This shortfall is expected to increase significantly unless new and substantial water sources are integrated into the system.
Conservative projections estimate that daily water demand will reach 1.6 million cubic meters by 2030, up from the current 1.2 million cubic meters. Accurately forecasting water demand in developing nations is complex, and my estimate may even be conservative relative to the true requirements.
AS: Are there specific areas in Addis Abeba that are particularly vulnerable to water shortages?
Tirusew: The disparity in water rationing across Addis Abeba is stark.
Some neighborhoods receive water twice a week, while others may only see a trickle every three weeks, or even once a month if they are fortunate. The Addis Abeba Water and Sewerage Authority's (AAWSA) rationing map starkly illustrates this inequity.
This disparity extends beyond mere scheduling. Wealthier residents can mitigate the impact of rationing by installing large water tanks, typically ranging from 10,000 to 20,000 liters in capacity. Unfortunately, this luxury is out of reach for many residents, exacerbating the hardship.
A common misconception is that acquiring a larger water tank solves individual water woes."
A common misconception is that acquiring a larger water tank solves individual water woes. While it may offer short-term relief, it does not address the fundamental issue: AAWSA's overall water supply currently meets only 40% of demand. Increased reliance on large tanks allows some residents to capture a larger portion of this limited resource, further jeopardizing those without storage capabilities.
Previously, residents might have received water once a week, but with the widespread use of large tanks, they might now receive water every two weeks or less, exacerbating water inequality within the city.
AS: Are you suggesting that the current water rationing strategy is ineffective and actually worsens the existing water crisis?
Tirusew: The true efficacy of Addis Abeba's water rationing plan depends on residents' experiences. Implemented since 2019, water rationing is at best a stop-gap solution.
Our research indicates that most cities, including Addis Abeba, were not designed to handle such disruptions. Repeatedly shutting down and restarting major transmission lines due to water scarcity causes pipe and pump damage, which exacerbates water loss and reduces the amount delivered to residents. This creates a vicious cycle where stricter rationing is needed to compensate for these losses, leading to further infrastructure damage and even less water availability.
Frequent pump shutdowns are costly in terms of energy use and significantly shorten pump lifespans. Ideally, pumps should operate continuously. From a utility management perspective, frequent on-off cycles create significant operational and maintenance challenges. Intermittent water delivery results in higher water loss and increased wear and tear on critical infrastructure, which is counterproductive to our goals.
Additionally, frequent shutdowns pose serious water quality issues. Most cities, including Addis Abeba, rely on chlorine or chloramine disinfection systems. These disinfectants have a limited lifespan in the water, depending on the source water quality and treatment levels.
Chlorine residuals typically last only a few days to a week. When the water system is frequently shut down and restarted, treated water stagnates in the pipes, leading to a decline in disinfectant residuals. This aged water becomes unsafe for drinking and contributes to the low tap water consumption in Addis Abeba.
AS: How does the existing water scarcity disproportionately impact specific demographics within the city?
Tirusew: Addis Abeba faces a severe water equity issue. While most major cities prioritize mitigating such disparities, the situation here is particularly alarming.
The Addis Abeba Water and Sewerage Authority (AAWSA) estimates there are roughly 600,000 billed accounts. However, secondary data reveals a concerning picture: only 20% of these accounts consume a staggering 80% of the available water.
This degree of inequity is rarely observed in other cities globally. We attribute this imbalance to wealthier residents utilizing large on-premise water storage tanks, ranging from 5,000 to 20,000 liters, during rationing periods. Consequently, residents in apartments and condos, lacking such storage capacity, face immense hardship during water rationing.
With limited water production and a growing reliance on private storage tanks, the frequency of public water distribution inevitably declines, disproportionately impacting those without storage space.
The disparity extends beyond rationing schedules. While AAWSA charges 7.25 birr for the first 1,000 liters, private vendors offering on-demand water can charge a staggering 1,200 birr for the same amount--a 165-fold increase.
Our analysis reveals a stark reality: residents in Addis Abeba who rely on Jerrycan deliveries pay 7 to 24 times more than those in the US or Europe. This translates to low-income households spending a staggering 10% to 20% of their monthly income just on essential cooking water.
AS: In the demand-supply imbalance equation, how impactful is the significant volume of water lost due to leaks and pipe breaks?
Tirusew: Let's clarify a common misunderstanding: when discussing Addis Abeba's water crisis and "wastage," the focus is often solely on pipe breaks and lost water. While fixing leaks is crucial, it is just one aspect of a larger challenge.
Non-revenue water (NRW) is a significant issue for utilities worldwide, representing the difference between the total water produced and the amount billed to customers. NRW includes various sources of water loss, both physical and intentional.
Physical losses consist of leaks and pipe breaks, while intentional uses involve activities like flushing water mains for quality maintenance or firefighting. Moreover, unbilled authorized consumption, such as water usage in public parks, contributes to NRW.
Unauthorized consumption, or theft through illegal connections, is a particularly worrisome source of water loss.
When addressing NRW in Addis Abeba, two crucial points must be considered. Firstly, achieving zero NRW is an unattainable target; even the most efficient utilities globally manage NRW between 10% and 20%.
Secondly, even if NRW were completely eliminated, it would not close the city's substantial demand-supply gap. The disparity is too vast to be bridged solely through NRW reduction.
AS: What challenges does Addis Abeba's current water supply system face, especially in relation to its dependence on groundwater?
Tirusew: Addis Abeba's heavy reliance on groundwater presents a major concern.
As a hydrologist and water utility expert, I understand that all usable water, whether from underground aquifers or surface sources like rivers, originates from precipitation. While groundwater has historically been beneficial for Addis Abeba, overdependence has led to the depletion of many aquifers.
Groundwater recharge is a slow and naturally limited process. Extracting water at a rate faster than it can replenish will deplete this crucial resource. This is the current dilemma facing Addis Abeba's aquifers.
Our research has revealed a troubling pattern: wells drilled to depths of 250 meters in the early 2000s are now unusable due to depleted reserves. Presently, most sites require drilling depths exceeding 500 meters, equivalent to the length of five football fields, to access groundwater. Even at these considerable depths, well yields diminish within a few years due to the "straw effect."
This effect illustrates the harmful consequences of unregulated extraction by multiple users, depleting the aquifer.
While fixing water leaks is crucial, it is just one aspect of a larger challenge."
As highlighted in our recent policy paper, Addis Abeba must not solely depend on groundwater as its primary water source. Our current extraction rate surpasses natural replenishment by rainwater. Establishing a diversified water supply strategy is crucial for ensuring the city's long-term water security.
AS: Do you believe the city municipality is on track to address the water crisis currently being experienced by the residents?
Tirusew: Although AAWSA has dedicated years to research, the envisioned crucial water projects have not come to fruition. Regrettably, it seems that the planning process has outpaced definitive action.
Our research reveals a substantial deficit, with only 40% of the current demand being satisfied. This clear reality is reflected in residents receiving water just two to three days per week.
Even if we were to consider a hypothetical scenario with 50% coverage, it would only result in a one-day improvement. Resident surveys indicate that the current situation does not even meet this modest level of access. The necessity for substantial and immediate action is indisputable.
AS: What public health hazards are linked to limited access to clean water?
Tirusew: Frequent shutdowns and restarts of water pipelines can create negative pressure zones within the system, potentially allowing contaminants to be drawn into the water supply. Additionally, stagnant water, both in the pipes and residents' storage tanks, can degrade water quality over time.
In Addis Abeba, there is a significant informal water market offering various water quantities, from Jerrycans to truckloads. However, the absence of regulations to guarantee the safety and quality of this water poses a notable public health risk.
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The water scarcity also has a cascading effect on wastewater management. Inadequate water flow can impede sewage systems' ability to efficiently transport wastewater, potentially resulting in system failures and associated public health issues.
Such circumstances could strain the city's healthcare system, necessitating unforeseen expenditures. This challenge was evident during the peak of the COVID-19 pandemic, when regular handwashing was a critical hygiene measure.
AS: To what extent do public education and behavior change play a role in fostering water conservation in the city?
Tirusew: Demand management is crucial for effective water utilities worldwide, especially in large cities such as Addis Abeba. It goes beyond simple water conservation to optimize water usage.
While demand management is essential for efficiency, it comes with costs. We consistently assess its cost-benefit ratio against potential investments in new water sources.
My background overseeing both supply and demand operations highlights the significance of making strategic decisions. Cost-effectiveness analysis serves as a practical tool for prioritizing interventions in Addis Abeba.
AS: From your professional perspective, what are the key actions that must be taken to tackle the water crisis in Addis Abeba?
Tirusew: The strategy to address the water crisis in Addis Abeba involves a dual approach: implementing structural solutions to enhance water supply and non-structural solutions to enhance governance and utility operations.
In the case of prioritizing a single crucial action, the focus should be on establishing a comprehensive surface water system that includes storage, treatment, and transmission infrastructure.
Emphasizing storage capacity is paramount, as it enhances the city's resilience. Greater storage capacity not only tackles the current water shortage but also strengthens Addis Abeba's capacity to confront the impacts of climate change, especially the anticipated irregular rainfall patterns in Ethiopia and neighboring areas.
AS: Apart from implementing a comprehensive surface water system, what additional complementary strategies should be pursued to address the ongoing water crisis in the city?
Tirusew: While I emphasize the importance of investing significantly in new surface water resources as the primary solution, I recognize the importance of complementary strategies. These include utilizing a combination of surface and groundwater, tapping into local sources and aquifer storage, and promoting enhanced water use efficiency, which involves reducing non-revenue water and implementing "Fit for Purpose" approaches.
Establishing appropriate pricing models, implementing mechanisms for cost recovery, and combining structural and non-structural solutions are all vital for driving rapid innovation. However, to achieve a lasting resolution, substantial investment in surface water resources remains the top priority.
