Nakuru: Nakuru County is embracing the ‘sponge city’ concept to combat the adverse effects of climate change and help promote sustainable social, economic, and water climate resilience to accelerate climate change adaptation. County Executive Committee Member (CECM) for Water, Environment, Energy, Climate Change, and Natural Resources, Dr. Nelson Maara, said the sponge cities concept would enable them to use existing features such as parks, lakes, and rivers to reduce climate change risks by offering a potential solution to control the damage caused by risks including floods, droughts, and land sinks.
According to Kenya News Agency, despite the presence of emergency response teams like the National Disaster Management Unit (NDMU), there is a growing need for proactive measures to prevent disasters. Dr. Maara cited the rapid increase in population, unplanned urbanization, climate change, uncontrolled land-filling for new residential areas, haphazard waste disposal into the drainage system, and encroachment of lakes, canals, and rivers as contributors to Nakuru County’s vulnerability to flash floods.
The CECM assured that Governor Susan Kihika’s administration is now embracing the ‘sponge city’ concept, which integrates green infrastructure such as parks, rooftops, and urban forests to absorb rainwater while revitalizing blue infrastructure like rivers and wetlands to improve stormwater management and biodiversity. He explained that a sponge city is designed to absorb, clean, and use rainfall in an environmentally friendly way, reducing pollution and hazardous run-off.
Dr. Maara added that sponge cities rely on natural resources such as lakes, rivers, grass, and soil to create absorbent ground surfaces that allow rainwater to be stored. ‘A city’s ability to absorb water, referred to as its ‘sponginess’, is key to withstanding climate shocks, with sponginess dependent on the amount of greenery and other water storage available,’ he explained.
During a workshop at a Nakuru hotel themed ‘Role of Sponge Cities in Sustainable Urban Development,’ Dr. Maara said the County Government is working on the Sponge City initiative in partnership with Water as Leverage (WaL) partners, UN-Habitat, the Netherlands Enterprise Agency, and Vitens Evides International (VEI). Nakuru City Manager Gitau Thabanja highlighted the importance of partnerships between governments, local communities, and the private sector in achieving financially viable and long-term solutions to natural disasters.
The manager explained that Nakuru’s sponge city program aims to use porous pavements, rain gardens, green roofs, urban wetlands, and other innovations to absorb water during storms, after which the soil purifies the water and gradually releases it, much like a sponge. ‘Green spaces in a sponge city’s design absorb carbon dioxide, contributing to a lower amount of greenhouse gas in the atmosphere,’ Thabanja added.
Last year, the County Government signed a memorandum of understanding with the Netherlands to enable Nakuru to adopt the Sponge City concept under the Water as Leverage (WaL) program, which aims to make the city withstand variable temperatures, drought, and heavy rainfall. Thabanja explained that the WaL Program, an initiative of the Netherlands government, promotes sustainable social, economic, and water climate resilience to accelerate climate change adaptation.
The WaL Program’s sponge city concept promotes a harmonious relationship between humans and nature, allowing water more room to soak in and pool in urban areas-such as parks that are dry in some seasons and become shallow ponds or channels in rainy seasons. The sponge city concept was first introduced in China in the early 2000s to address surface-level flooding in urban areas, with pilot projects initiated in several Chinese cities in 2014.
As climate change leads to more extreme weather events like heavy rainfall and droughts, it has become crucial to integrate floodwater management systems in cities. The World Meteorological Organization reported that around 44 percent of global weather-related disasters in August 2023 were linked to flooding, highlighting the urgent need for preventive measures. The World Economic Forum (WEF) found that ‘nature-based solutions to climate change’ are up to 50 percent more cost-effective than engineered alternatives.