Nakuru's transformation into a city is being written in concrete and steel, as gleaming towers rapidly replace colonial-era bungalows. But beneath the foundations of this vertical ambition lies a dangerous truth: the city is built on geologically unstable ground, crisscrossed by active fault lines.

The rush for vertical expansion directly challenges long-standing warnings from geologists and seismologists who have cautioned for decades against constructing buildings taller than five storeys. This rapid development, driven by high demand for housing and office space, is creating a high-stakes gamble where the prize is economic growth, but the risk is a potential catastrophe.

A City on Edge

The science is not new. A June 2020 report co-authored by seismologists and geologists warned that Nakuru sits on a major fault line, making it vulnerable to sinkholes and structural failures, especially during heavy rains. Experts have identified several weak spots, including the neighbourhoods of Kaptembwo, London, Kiamunyi, Shabab, and Ngata. The region's history is punctuated by ominous signs: in May 2024, heavy rains triggered massive fissures and sinkholes, displacing over 500 families in Kaptembwo. Geologists explain that the area is covered in a layer of volcanic ash and loose soil that is easily washed away, exposing deep subterranean cracks.

Despite these clear and present dangers, buildings reaching 14 storeys and higher are now part of the city's skyline. This has prompted alarm among professionals. Architects have voiced concerns that development is proceeding without a comprehensive, city-wide geological survey to map out high-risk zones. “What appears structurally sound today could become tomorrow's catastrophe,” warns geoscientist Dr. Isaac Kanda, who has called for an urgent review of existing buildings and stricter zoning laws.

Assurances Versus Reality

Developers and city officials maintain that safety is a priority. Nakuru City Manager Gitau Thabanja has stated that all high-rise plans undergo rigorous approval by both county and national authorities. Architects involved in these projects point to the use of advanced engineering techniques to mitigate the risks. “We prioritise deep, reinforced foundations and advanced pillars to ensure the buildings' structural integrity,” noted architect David Mwangi. These modern methods, they argue, can ensure the stability of tall structures.

However, the disconnect between official assurances and the geological reality on the ground remains a core tension. The warnings are stark:

• In 2018, a section of the Mai Mahiu-Narok road, also within the Rift Valley, was split in two by a volcanic fault line after heavy rains.
• Nakuru has a documented history of building collapses, including a four-storey building in the CBD in 2017.
• Experts from the University of Nairobi have explained that subterranean erosion is constantly occurring, creating underground voids that can suddenly collapse.

The national government has recently taken steps to modernize building regulations. The new National Building Code 2024 replaces the outdated 1968 version and mandates stricter adherence to safety standards, including designs for earthquake resistance. Yet, for Nakuru, the critical question is whether these new regulations will be rigorously enforced and informed by detailed geological data that is currently lacking.

For the average Kenyan looking for a home or a place of business in Nakuru, the rising skyline is a symbol of opportunity. But it is also a daily reminder of a risk that lies just beneath their feet. The future of the city depends on whether its growth is built on a solid foundation of scientific foresight or on a dangerous disregard for the ground's own warnings.