Key facts
- Nairobi County disaster management chief Bramwell Simiyu said drainage systems have been untouched for many years.
- Simiyu said the drainage system was built 30 years ago for about 2.5 million residents; the city now holds about 7 million in the daytime.
- Simiyu said up to $192 million is needed to fully upgrade Nairobi's sewerage and drainage system.
- Simiyu said a worst case could put up to 100,000 people at risk, with a moderate projection of about 5,000 households or 20,000 people.
- Simiyu said people forced to leave their homes would go to 167 designated holding grounds stocked with relief food and supplies.
- Forecaster Jemima Gacheru told the BBC that Indian Ocean temperature conditions resemble those of the 1997 El Niño, which brought very strong rainfall.
Nairobi County crews are shovelling and raking garbage out of the Ngong riverbed and unclogging drainage systems across the Kenyan capital ahead of the short rainy season, the BBC reported on November 11, 2026. Blocked drains and inadequate sewage systems were widely blamed for the high number of deaths after floods earlier in 2026, when more than 60 people died across the country.
Nairobi County disaster management chief Bramwell Simiyu told the BBC the drainage systems had been "untouched for many years" and that removing the rubbish would save lives. He said the existing system was developed 30 years ago for about 2.5 million residents, while the city now holds about 7 million people in the daytime and 5.5 million at night. Upgrading the sewerage and drainage system entirely would need investment of up to $192 million, he said, with little sign that the national government or city council could raise the money.
Simiyu said a worst case for low-income settlements could put up to 100,000 people at risk, while a moderate projection was about 5,000 households, or about 20,000 people. Anyone forced to leave would be relocated to 167 designated holding grounds stocked with relief food and supplies, he said.
In Kibera, one of the largest informal settlements, Agnes Shikoli said floodwater reached halfway up the wall of her home in March and that her sister Beatrice Khalayi, 58, died of electrocution after her house flooded. Shikoli, 62, who sells groundnuts and fruit for about $2 a day, said council officials had told her family to leave the riverbank until the rainy season passes, but that she lacked the means to move.