NWHSA urges long-term water management to address severe floods

National Water Harvesting and Storage Authority (NWHSA) CEO Julius Mugun has called for a long-term shift in how Nairobi manages stormwater following severe flooding that has paralysed major roads and left several residential estates submerged.

Mugun expressed concern over the impact of the floods on residents and motorists, some of whom were forced to spend the night on waterlogged roads across the capital.

The flooding disrupted movement along key transport corridors, including Mombasa Road, Kenyatta Avenue in the CBD, Thika Road, Dunga Road and Enterprise Road, while homes in estates such as South C, Embakasi and several informal settlements were also submerged

According to the NWHSA boss, the situation highlights the city’s vulnerability to increasingly intense rainfall and exposes the limitations of the current drainage infrastructure.

“The volume of stormwater we are witnessing is overwhelming our current urban infrastructure, much of which was not designed to handle these increasing flows,” Mugun said.

“When drainage is clogged or overwhelmed, it's not a localised issue for South C or the informal settlements; it affects the entire economic ecosystem, leading to the massive disruptions we saw yesterday on major roads.”

He noted that the volume of water generated during heavy downpours now exceeds the capacity of many drainage systems, some of which have surpassed their design life.

Mugun said the recurring flash floods demonstrate the urgent need for a dual strategy that combines improved drainage with aggressive water harvesting initiatives.

“We must fundamentally change our perception of stormwater from a nuisance to a valuable asset. Every cubic meter of water we harvest is a cubic meter that doesn't flow down to flood a home or submerge a major highway. It is a critical link between flood control and water security that we can no longer ignore in our urban planning," he said.

The NWHSA CEO said the authority is working with urban planners and county governments to develop sustainable water management systems aimed at controlling runoff while boosting water storage.

“Our strategy includes not just large dams, but small-scale water pans and mandatory household harvesting, which can collectively reduce the peak flow into our urban drainage systems,” he explained.

Mugun added that upstream storage reservoirs and distributed water harvesting systems within residential areas could help reduce pressure on urban drainage networks during heavy rains.

As the Kenya Meteorological Department warns of continued rainfall, the NWHSA boss urged authorities to prioritise long-term infrastructure investments to strengthen the city’s resilience.

“We cannot afford to keep addressing these disasters with temporary fixes. To truly protect our capital city, we need a concerted, long-term investment in our water harvesting and storage infrastructure that builds resilience against these inevitable climate shocks,” he said.

The authority maintains that expanding water harvesting and storage infrastructure remains key to improving water security while reducing the devastating impact of floods in urban areas.