The swoop comes a day after President Uhuru Kenyatta launched the green space in the city with promise of rejuvenation of more spaces.
NEMA officers apprehended the landlords stating that their structures were within the riparian reserves of the park.
The team of inspectors led by Director General Mamo B. Mamo found that the houses were also discharging untreated effluent directly into the Nairobi River at the Kirichwa river.
In addition to the arrests, the officials also ordered the 16 affected tenants to vacate the houses until the landlords connect to the sewerage system.
During his address on Friday, August 14, President Kenyatta pointed out that besides Michuki Park, the government was working on renewing several other green spaces within the city among them the Nairobi Arboretum, Karura Forest, City Park and Ngong Road Forest.
â€œAnd we hope to extend this re-birth of our environment or what I call the â€˜green renaissanceâ€™ to all counties of the Republic,â€ he stated.
The President added that every Kenyan had a responsibility to conserve the environment as he regretted mistakes of the past, especially weak enforcement of environmental and sanitation that led to Nairobi losing its green city status.
â€œAs Government, we did not enforce the civic responsibility of the citizen to take care of the green spaces. And the citizens of Nairobi city were not organized enough to protect it.
â€œBecause of this, and the rapid growth of â€˜concrete spacesâ€™ over the â€˜green spacesâ€™, there was a collapse of civic order and national duty in the city,â€ he added.
Urban green spaces such as parks, sports fields, woods, lakesides, and gardens give people the space for physical activity, relaxation, peace, and an escape from heat.
Green spaces are also associated with better air quality, reduced traffic noise, cooler temperatures, and greater diversity.