The recurring flooding that plagues Nyabugogo, Kigali’s commercial center housing the main terminal for commuters to different parts of the country, could soon end following multibillion-dollar installations, including the new Muhazi sea wall being built. construction to control flooding.
The area lies between the Nyabugogo river and the Mpazi drainage which usually floods and affects businesses.
Researchers warn that businesses around the Nyabugogo River and its other water catchment areas in Kigali could suffer further losses from flooding if no urgent action is taken to address the issue.
A few vehicles stuck on a flooded road in Nyabugogo in 2019. Photo: File.
According to studies, small businesses in the region lose 178.2 million Rwf per year due to recurrent flooding to which the Nyabugogo River also contributes.
The Nyabugogo River is 45.97 km long, measured from the outlet of Lake Muhazi in Orientale Province to its confluence with the lower course of the Nyabarongo River near Kigali.
Davis Bugingo, director of the flood management and water storage development division at Rwanda Water Resources Board (RWB) said the construction of a new Muhazi dike which will cost Rwf 3 billion to reduce flooding towards the Nyabugogo shopping center will soon be completed.
“The current unprotected sea wall is breaking and threatens to flood the Nyabugogo area, a commercial hub in Kigali city, and cause significant damage to property and lives. The new dike is very crucial to tackle such problems, ”Bugingo explained.
A dike is a long wall or embankment or barrier built to prevent flooding by regulating or retaining water from a river, lake, or even the ocean.
Lake Muhazi, which is a flooded valley lake where the dike is being built, stretches for about 38 km.
Drained by the Nyabugogo River, the lake empties into the Nyabugogo River, which flows south to Kigali where it meets the Nyabarongo River, which is part of the Upper Nile.
An integrated water resources management plan shows that three main programs, namely the fight against urban floods and the restoration of the Nyabugogo wetlands in Kigali, the protection of Lake Muhazi by promoting non-consuming and efficient use water supply as well as watershed restoration, agricultural land improvement and rainwater harvesting could reduce flooding.
The new Muhazi embankment being built by China Geo Engineering Corporation, to replace the old one, will be 6.5m high with a ridge elevation of 1437.5m where it is expected to be completed in September 2021.
The current old sea wall was built in 1999 as an emergent solution, but the lake was drying up due to an uncontrolled outlet.
Businesses in the Nyabugogo region have called on the government to speed up flood control facilities at the start of the rainy season.
Pierre Muhire, a businessman who sells food and drink around Nyabugogo bus station, remembers when his store was submerged by flooding in April of last year.
“The water comes from different corners, especially the Mpazi drainage and the Nyabugogo river. I have suffered a loss of around 60 million Frw and have yet to recover from the losses due to the additional effects of Covid-19. It is better that the construction of the flood control facilities that we see be accelerated before the rainy seasons hit us again, ”he said.
Muhire said he was struggling to repay his bank loans because of the huge losses.
Mpazi drainage extension
The city of Kigali has also started to rehabilitate and expand the Mpazi drainage which has caused flooding.
Drainage collects wastewater and rainwater from homes in Nyamirambo, Gitega and Kimisagara sectors all in Nyarugenge, towards Nyabugogo.
During heavy rains, floods destroy several properties and carry debris to the Nyabugogo valley.
The RWF 8 billion project began with the expansion of two major bridges to allow drainage water to flow directly into the Nyabugogo River.
The city of Kigali is also seeking to rehabilitate and expand several drainages that typically cause flooding in the country’s capital, requiring funding of Rwf 30 billion.
According to officials, more than 40 drainages need to be rehabilitated and expanded.
Last month, Parliament approved € 6 million (over Rwf 7 billion) in funding from the Nordic Development Fund (NDF) to fight flooding and build drainage in the city of Kigali.
As part of the funding, € 4 million is a loan while € 2 million is a grant. The 31-year loan will carry an interest rate of 0.75% with a six-year grace period.
Telemetry stations to monitor floods
In addition to infrastructure that curbs flooding, telemetry stations are installed at identified flood hotspots across the country, including Kigali, to establish early warning systems to reduce the impact of flooding.
Telemetry is the automatic recording and transmission of data from remote or inaccessible sources to a computer system in a different location for monitoring and analysis.
Stations should monitor trends or peak flows of rivers, drainages, and other flood hotspots as part of early warning systems aimed at minimizing likely flood impacts and planning for flood-resilient infrastructure .
Telemetry stations are real-time sensors and can measure water levels instantly with an interval of 5 minutes, 15 minutes or 30 minutes according to Remy Norbert Duhuze, head of the monitoring and quality control division of the water in Rwanda Water Resources Board.
So far, 24 telemetry stations have been installed, as their number is likely to increase in the coming years.
“Flood hotspots have been identified and more telemetry stations will be installed to strengthen the early warning system. Telemetry stations are essential for better management of water resources and to overcome some problems related to flooding as well as to improve water sharing through appropriate water allocation, ”he said.
Most of the stations, he said, were installed in the catchment area of the Sebeya, Mukungwa and Nyabarongo rivers, while other sensors were installed on shared water bodies and lakes.
The new targeted flood hotspots, he said, are located in the Nyabugogo River watershed in Kigali city and other telemetry stations will also be installed in the Rwampara sub-watersheds, Rwandex, Kinamba and Mulindi.