Provisional results of the 2012 National Housing and Population Census indicate that Kigali City is home to 1.1 million people, which translates into 10.8 per cent of the total population of Rwanda.

The high population poses a major challenge to city authorities when it comes to providing adequate social amenities and experts argue that some of them might collapse if the pressure increases.

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Figures from the national utility agency, for example, indicate that the city’s population currently consumes 62,000 cubic metres of water compared with 55,000m³ last year, an increase of 7,000m³.

Contracted private firms

However, according to the department, the actual water need of the city is 82,000m³, meaning some areas, particularly lower-end suburbs, do not get adequate water supply.

“Every year, we anticipate an increase of six to 10 per cent in the demand for water due to increased needs,” said Theoneste Minani, the head of Water and Sewerage Utility at Electricity and Water Services Authority (EWSA), the national utility agency.

However, despite the challenges facing the city in meeting the water needs of its residents, the engineer said, the authorities have made huge strides in improving the standards of living in the city.

“We have contracted private firms in every sector to collect solid waste. We are keeping the city clean,” Alphonse Nizeyimana, Kigali City vice-mayor for finance and economic development, said.

Kigali has distinguished itself in the East African region for its success in keeping its streets well lit, efficient garbage collection and regular road maintenance but the fact that the city sits on a clogged sewerage system poses a sanitation challenge.

Officials at the city council say some 110m³ in liquid waste is generated in Kigali per day from commercial buildings and the few self-contained units in the affluent suburbs. This on top of other unknown volumes in pit latrines in the compounds of homes in both upper- and lower-end suburbs.

Since the majority of residents in Kigali want to live in self-contained detached houses, this, coupled with improved water supply, means an increase in liquid waste in coming years.

Swim in a sea of human waste

“In case of an earthquake, this city would swim in a sea of human waste,” a senior government official hinted.

A collective sewerage system is yet to be realised as a $70 million (Rwf44.3 billion) financing proposal submitted to the European Development Bank is yet to be approved.

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Experts say collective sewerage systems may not be good because, in case of failure, the entire city would suffer the consequences, which calls for multiple sewers to enable back-ups and make maintenance of the system easier.

Mr Minani said 80 per cent of water consumed is very likely to turn into liquid waste, conceding that it creates a sanitation threat to urban centres in Rwanda and Kigali in particular.

To address the problem, the city authorities are now making it mandatory for commercial properties and real estates to provide for sewerage treatment systems before they are issued with construction permits.

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Experts still sceptical

Experts are however still sceptical: They accuse the authorities of paying lip service to sanitation issues and cite the emerging suburbs with corresponding improvement of the city’s social amenities.

The past few years have seen new suburbs – such as Nyarutarama, Kibagabaga, Kinyinya and a section of Kimironko – come up and environmental experts argue that city authorities should have a plan for adequate amenities there.

“What we have [clogged sewerage] is poor sanitation in urban planning terms,” Charles Mugabo, who specialises in environment sciences and sits on the Rwanda Bureau of Standards committee on waste management, said.

Mr Mugabo argues that the council can start by putting up sewerage treatment systems and other amenities at the suburbs.

A standard septic tank to accommodate sewerage for a three-bedroomed house costs Rwf1,500,000, a price experts say could go down were homeowners to contribute communally. However, there is a need for the government to come up with proper standards to ensure the septic tanks are of high quality.

EWSA officials say 28,000m³, or 45 per cent of the water consumed in Kigali, is pumped out of River Nyabarongo, which gets much of its flow from Nyabugogo River which experts suspect is polluted by sewage from suburbs such as Muhima and the Central Business District.

Once the rivers are polluted, experts say, the cost of water treatment goes up and quality of household water for surrounding communities that do not have access to piped water is compromised, which increases prevalence of water-borne diseases such as typhoid.