MPs have blamed contradictory laws for the wanton destruction of wetlands in Nairobi.
The MPs also said the mandate of the National Environment Management Authority (Nema) was overstretched, making it easy for private developers to circumvent the law.
The Parliamentary Committee on Environment and Natural Resources said food and water security has been threatened by encroachment of wetlands.
"We're sitting on a time-bomb. Something must be done," Kasipul Kabondo MP Charles Were said.
He spoke on Tuesday when Environment Chief Administrative Secretary Mohamed Elmi appeared before the Kareke Mbiuki-led committee at County Hall.
Homa Bay Town MP Peter Kaluma has sought to know whether there were laws for the protection of wetlands and riparian lands.
Elmi responded in the affirmative, citing the Water Act, 2002, Water Resource Management Act 2007Environment Management and Coordination Regulations of 2006 among others.
MPs pointed out contradictions in the laws. For instance, the Environment Management Coordination Regulations of 2006 puts the recommended riparian distance at a minimum of six metres and a maximum of 30 metres from the highest water mark. The Agriculture Act puts it at a minimum of two metres.
He also wanted to know the approval process of buildings and in particular the Alina Villas on lower Kabete road, Kibarage valley, Nairobi and Jamhuri Estate along Langata road.
The MP also wanted to know measures being undertaken by the ministry to ensure wetlands areas as well as riparian lands are protected including those along the coastline.
Committee Members Francis Chachu, Charity Chepkwony, Charles Were,Hillary Kosgei, Paul Nzengu,Hassan Hulufo and Rehema Hassan attended the session at County Hall.
Through the Chief Administrative Secretary, Mohamed Elmi, Tobiko said there are several laws on protection and management of riparian reserves.
This included, Elmi said, the Environment Management and Coordination Act, CAP 387, Environmental Management and Coordination (water quality) regulations, 2006, the Water Act, 2002, Surveys Act, CAP 299.
Others are Agriculture Act, CAP 318,the Physical Planning Act CAP 286 and Water Resource Management Act, 2007.
However, nearly all the laws contradict on the recommended riparian distance.
For instance, Environmental Management and Coordination (water quality) regulations, 2006 puts the recommended riparian distance at minimum of six meters and a maximum of 30 meters from the highest water mark.
Agriculture Act CAP 318 recommends a minimum of two meters and a maximum of 30 meters.
It however does not indicate from what point.
On the other hand, Survey Act 1989 recommends 30 meters from tidal rivers but does not mention other rivers.
The Part Development Plan of 1968 indicates a minimum of 30 meters from Nairobi River between Museum Hills and Racecourse round about.
For other Rivers, the development plan recommends a minimum of 10 meters and maximum of 50 meters.
The MPs asked Nema to explain how private developers got approvals to put up apartments, some of which lie on riparian lands and wetlands.
Wetlands are lands consisting of marshes and swamps. They include mangroves and peatlands, rivers, lakes, deltas, floodplains, flooded forests, rice fields and coral reefs.
Nema deputy director for compliance Zephaniah Ouma said the authority needs capacity building.
Nema was also put on spot for allowing a private developer to put up structures in Kibarani, Mombasa, a move that has led to pollution.
Ouma said the licence was issued based on a Kenya Port Authority's strategic plan which said the developments would support ports infrastructure.
A number of buildings on riparian lands have recently collapsed, killing and injuring scores.
In 2016, the government formed a multi-agency team to check on the encroachment on riparian reserves. The team has audited 4,901 buildings countrywide.
Elmi said he needed a month to provide the list of buildings that have been demolished, those yet to be demolished and the reasons why.
Mbiuki said the committee will conduct a fact-finding tour of Nairobi River and Homabay and Mombasa counties to access the destruction on wetlands.
Already drafts wetlands regulations banning human activities within 30 metres of river and lakeshores and 60 metres from the Indian Ocean shore have been developed.
The Environmental Management and Co-ordination (Conservation and Management of Wetlands) Amendment Regulations, 2018 are set to be reviewed.
Wetlands ecosystems are expected to get much more protection following a review of laws governing their management.
Human activities will not be allowed within 30 meters of the shores of major rivers.
Wetlands International has been supporting the review of the National Wetlands Regulations for Kenya since April 2017.