China Railway Construction Engineering Group (CRCEG) is embarking on setting up the Kigali Centralised Sewerage System, slated for completion in 2026, according to the Water and Sanitation Corporation (WASAC).

The project works started in August 2023 with a thorough study and site setup at Giti cy’Inyoni in Nyarugenge District, Dominique Murekezi, Ag. Managing Director at WASAC Development Ltd, told The New Times on Monday, April 29.

It will cover a network of 89 kilometres across Kigali City and will have a wastewater treatment plant with a capacity to treat 12,000 cubic metres (m3), according to Murekezi.

He pointed out that the detailed study is underway and will be finalised by the end of June, after which a full-scale execution of the project will start (in July). He added that the project will be implemented within 30 months to be completed in February 2026.

Murekezi provided details about the project which the Public Accounts Committee (PAC) said was long overdue, during Monday hearings in which officials from WASAC were responding to the irregularities in public asset management raised by the report of the Auditor General for the financial year 2022/2023.

The overall objective of the Kigali Centralised Sewerage System project is to improve collective sanitation services through consumer connections to a networked sanitation service within the City of Kigali, along with the construction of a wastewater treatment plant, according to its proponents.

Murekezi said that the China Railway Construction Engineering Group won the tender in April 2023.

According to information from the African Development Bank (AfDB), one of its financiers, seven firms from four countries – namely China, Portugal, Mauritius, and Egypt – bid for the project.

While the government secured €87 million (about $93 million, or Rwf120 billion at current exchange rates) – from the European Investment Bank (EIB) and the African Development Bank – to finance the project, the contractor charged about $65 million (approx. Rwf90 billion), Murekezi said Kigali Centralised Sewerage System is one of the key projects under the Rwanda Sustainable Water Supply and Sanitation Program (RSWSSP) which, among other expected outcomes, will address the lack of a centralised treatment facility for sewage, according to information from WASAC.

The abovementioned report of the Office of the Auditor General pointed to delays in the project execution, indicating that it was to run from January 2018 through June 2024, but that period was extended to June 2026.

By December 2023, the report observed, seven activities under the project had either not been started or were at early stages of being executed. They include Kigali Centralised Sewerage System whose contract was in the early stages of execution.

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Why govt opted for design and build model

Because of the complexity of the project, as it concerns a site that is a city already inhabited and has diverse infrastructures in place, and new ones being set up, the government had to be careful about its implementation model, Murekezi said.

As such, it adopted a design-build model, where the contractor carries out the design and construction of the system.

"You realise that it is a project which, however much you can carry out a detailed study, there will be changes in its execution,” he said, pointing out that there are factors that a detailed design cannot indicate, referring to the ever-changing infrastructures of Kigali, including roads and buildings, as well as the state of already existing houses.

He observed that wastewater generated from households, and commercial buildings will be connected to the sewage network for a treatment plant for purification, adding that houses such as those in Kigali Business District, have toilets, and most of them have septic tanks.

For that to be achieved, he said, manholes must be constructed and will help channel the sewage into the network for subsequent treatment.

Murekezi pointed out that such manholes must be positioned at a level below the location of such septic tanks to ease the sewage flow into them; otherwise, if the manholes were at an upper level, it would require a pump to drive the water into them.

The design-build model factors in all changes that might emerge during the project implementation, he said, meaning that the contractor will have to respond to them as they arise, without the need to change the contract with the government.