Ethiopian Business Review

What is the way Out

In recent years, Addis Ababa has been increasingly affected by flooding due to its vulnerability to rainfall and flash floods.  The vulnerability to flooding has been further aggravated due to a poor drainage system, rapid urbanization and climate change, which have lead low-income communities to settle in flood-prone areas. EBR’s Ashenafi Endale explores the extent of the damage as well as what the government is doing about it.

Heavy rain on the afternoon of June 20, 2018, saw pedestrians, vehicles and even light railway mobility jammed up for more than three hours around CMC square. The square accommodates vehicles coming from four directions, as well as the east-west light railway line.  

 “Traffic flow was stuck the whole afternoon until the flood level came down,” one city resident at the scene told EBR. “You can imagine how many people were affected by the flood and lost their precious time.”

The issue around CMC is not a unique phenomenon in the capital. In fact, it is common to see rain and storm water filling many streets and highways in Addis, especially during the rainy season. And even though it is rare, due to heavy showers and the resulting flooding, some people in the capital have been forced to move, like the hundreds of residents living around Ambassador Theatre, Arat Kilo and Piassa, who had to leave their homes after they flooded three years ago. 

Although the government has not officially released any statements regarding the issue, many areas are becoming vulnerable to flooding in Ad dis Ababa. These include areas around Semien Mazegaja, St. Rufael Church, Addis Ketema Preparatory School and Habte Giorgis Bridge as well as around the headquarters of the  National Bank of Ethiopia and Filwuha, according to series of studies conducted by the Ethiopian Institute of Architecture, Building Construction and City Development (EiABC) and the University of Copenhagen between 2015 and 2017. 

Alazar Assefa, a lecturer at EiABC who was involved in the studies, stresses that the extent of the problem has worsened, especially in the last decade. “Ten years ago, only 20 to 30Pct of the rain water volume was thought to be converted to flood, while 30Pct was consumed by plants. The remainder used to be absorbed by soil,” he explains. “Due to high deforestation and soil degradation in the mountain chain that surrounds Addis Ababa in the last decade, the volume of rain water that reaches the city has climbed.”

Dereje Birhanu, lecturer at the Korea University of Science and Technology in a 2016 study entitled ‘Flood Risk and Vulnerability of Addis Ababa’ also says that the increase in intensity and frequency of flooding in Addis Ababa can be mainly attributed to rapid urbanization and climate change. Even though no assessment has been conducted to identify vulnerable and risky areas of the city, Dereje argues that flooding is more intense in Addis Ababa due to dramatic urbanization as well as heavy rainfall and extreme weather. 

In order to quantify the changes due to climate change and urbanization, Dereje undertook a careful calibration and uncertainty analysis considering two satellite images and general circulation models. The result indicated a 10Pct and 25Pct increase in peak flow over the last decade due to climate change and urbanization, respectively.

Despite this, however, Addis Ababa, a city of close to four million people, still remains without an efficient drainage system. Of course, building drainage infrastructures such as canals at the same time as road construction dates back more than 50 years ago. But the disorganized and uncoordinated activities undertaken to strengthen the management of drainage systems did not solve the problem. Currently, the city’s road coverage is around 20Pct while the road networks reach 3,100 kilometres, according to the Addis Ababa City Roads Authority (AACRA). 

Experts say that it is simple to prove that only insignificant numbers of the canals constructed along these roads are functional. “To begin with, not all the roads have proper canals, sometimes because they are built without meeting the standards,” explains Sisay Zenebe, another senior lecturer at EiABC. “A significant portion of canals that fulfil the requirements are not functional because they are filled with household and industrial solid waste, as well as sewerage.”

Although Habtamu Tegegne, director general of AACRA, the authority responsible for constructing drainage infrastructures along the roads, agrees with experts who stress that Addis Ababa is becoming increasingly vulnerable to flooding, he says that it is important to identify the various sources of the problem in order to arrive at a better conclusion. “There are three sources of flooding. The first is the descending rain water from the mountains surrounding the city, which is increasing in volume due to deforestation,” he told EBR. “Currently, there is no public institution responsible for preventing the rain from reaching the city.”

The second source is rivers, according to Habtamu. “When rivers become full they overflow and flood the city. For instance, due to seepage, the Akaki River frequently causes flooding in the surrounding area. Just as before, there is no entity to manage such incidents at the moment.” 

The third source of flooding, Habtamu says, is linked to the roads built by the Authority. “When the drainage canals constructed along the roads cannot accommodate the storm water, they cause flooding. Many people are confused about who is responsible for the flooding issues in the city.”

Officials at AACRA say that although the Authority is responsible for the canals constructed along the roads, it is not in charge of networking the different canals in the city. The lack of canal networking is a serious problem in Addis Ababa due to the fact that the canals installed in the city have different diameters, making it impossible to link them. The diameters of old canals in areas like Arat Kilo, Piassa, Mexico, and Stadium range from 30 to 60 centimetres. On the other hand, the newly built canals reach up to one meter in diameter. 

Due to the small diameter of canals installed 30 years ago, interconnecting them with the new ones is a daunting task, according to Habtamu. “On top of this, most of the old drainage infrastructure remains worthless due to solid waste and garbage. However, the newly installed canals are working efficiently.”

Tesfaye Misganaw, general manager of Afro-Tsion Construction, disagrees with Habtamu’s suggestion that less than 50Pct of the existing drainage canals including the newly constructed ones, are functioning, although there is room for improvement. “The first issue when it comes to drainage infrastructure is precise design,” Tesfaye argues. “The design should accommodate not only current storm water but future circumstances as well.” 

“The lack of expertise in the area is another hurdle,” Tesfaye says. In addition to building two roads in Addis, Afro-Tsion is undertaking an additional three road projects at the moment. 

Experts also told EBR that, in principle, canals should be built to last up to 20 years. However, in Addis Ababa drainage canals are mostly designed considering flood forecasts for five years. 

Before construction is started, Tesfaye says, drainage infrastructures must be designed considering 20 to 50 years of forecasts; software that provides the data is available in the country. Yet most canals are designed and built without utilizing such technologies.

“So far, it has been thought the drainage problem can be solved with routine cleaning and replacing the small canals with large ones,” says Habtamu. “But these interventions can only serve as short and medium term solutions.”

Both Habtamu and Tesfaye agree that the ultimate solution is preparing a drainage master plan and putting it into practice in an efficient manner.  “The problem is becoming serious because there is no drainage master plan,” Tesfaye stresses. 

Officials at the Authority have long since  considered a drainage master plan for Addis Ababa, but until four months ago no concrete moves had been made. Then, in March 2018, ACCRA floated a tender for the preparation of a drainage master plan for the city, after cancelling successive tenders in the past without justification.

This is why experts in the field such as Jemal Mohammed, general manager of Blue Matrix Consultancy, a company involved in the preparation of drainage master plan for five regional cities, say there is still a lack of commitment and willingness from the government side. “The drainage master plan is delayed because of politics rather than technical and capacity related issues,” explained Jemal.

Habtamu, on the other hand, contends that preparing a master plan for Addis Ababa has been delayed due to the complexity of the problem. “It needs detailed studies to decide what type of drainage master plan will be suitable for the city.” The Authority is undertaking these studies with the support of the World Bank. 

Currently, the Authority is in process of selecting companies for the design of the plan. “We are in the final stages of the tender process,” says Habtamu. “The master plan is the only feasible solution. However, it comes at a high cost since the master plan might suggest the demolition of  a significant portion of the existing drainage infrastructure.”

Still, others still remain cynical because the problem requires a lot more than preparing a master plan. “If problems related to solid waste and sewerage management cannot be solved, the canals will continue to be blocked,” argues Sisay. 

Kefargachew Kassahun, Environmental Management team leader at the Ethiopian Roads Authority agrees with Sisay. “Most drainage infrastructures are underutilized due to lack of proper care once they are built.  The city administration used to pay households who cleaned the canals in front of their houses. But this is a thing of the past.” 

To address the sewerage problem, projects to build new sewerage canals and install a sewerage refinery plant around Akaki are underway, financed by the city administration and the Wold Bank, which allocated USD300 million. The sewerage plant is expected to refinery 100,000 cubic meter sewer per day and started work this month.


6th Year . July 16 - Aug 15 2018 . No.64


 

 

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