Residents of Mukuru Kwa Reuben and Mukuru Kwa Njenga watched as their houses were being demolished on Monday.
A bulldozer was on site bringing down several structures in the two areas.
Affected residents could be seen moving their belongings.
This comes after President William Ruto directed residents living in riparian areas and along the river banks to move to higher grounds.
The ongoing heavy rainfall has resulted in flooding across the country.
Shortly after the demolition, some residents constructed houses at the roadside a few meters from the ones which were demolished.