The National Land Commission is working on a plan to evict property developers who have encroached on riparian lands.
NLC vice chair Abigael Mukolwe said the commission is set to issue a 90-day eviction notice to the affected persons and companies.
She said encroachment of riparian lands is the cause of flooding witnessed in Nairobi and its environs recently.
"Flooding is destroying our infrastructure, killing people and causing strange diseases such as cholera. We can't allow this to continue."
Mukolwe unveiled the plan during an interview with The Star at her office in Ardhi House on Monday.
The move is likely to send shock waves among prominent individuals accused of erecting multi-billion storey buildings on a riparian land.
A Sh1 billion commercial building on the banks of Ngong River along Lang’ata Road is among those earmarked for demolition.
The building, owned by a former MP, was listed for demolition by a committee formed to audit unsafe buildings and those on wetlands.
"An illegality is an illegality. In this country, we have the rule of law which everyone must respect," Mukolwe said.
She said NLC will not sit back and watch developers grab riparian lands in the wake of the threats to the environment.
"We are not going to allow some people to flood others. Everybody must get off the riparian land for our own good," she said.
Mukolwe said Article 67 of the Constitution says riparian land is public land hence not available for allocation to anyone.
NLC, which is chaired by Muhamad Swazuri, is developing a policy paper on riparian land.
The policy paper, which is set to be unveiled soon, will provide a framework of how riparian land is going to be managed throughout the country.
It will be shared with the national and county government.
Mukolwe said: "Let the county and national government also take up as they have the machinery to remove these people from the waterways."
The NLC boss said the commission has noted with concern that almost all the riparian land is in the hands of private individuals.
"This is an illegality," she said.
Article 62 of the Constitution says all rivers, lakes as defined by an Act of Parliament and all land between high and low water marks are public lands.
NLC manages public land on behalf of the national and county governments and also recommends land policies to the national government.
Areas within Nairobi that were classified as flood hotspots in 2016 are South C and Nairobi West.
Other areas were Kileleshwa, Imara Daima, Thika Road, Langata, Loresho, Zimmerman, Garden Estate, Thome, and Roysambu.
Kahawa West, Donholm, the Mbagathi/Langata Road Roundabout, Nairobi West, Ruai, Utawala, Mukuru slums and Kibera slums were also identified.
Heavy rains have been pounding the county for some days, making movement very difficult.