Residents of Lari Kirenga ward in Kiambu county have opposed a plan by the county government to zone the area as a heavy industrial park.
Uplands Nyambare Residents Association chair Francis Muregi said an investor has already bought land in the area to build an industry.
"If this area is zoned, all of us might be in a risk. We do not want such zoning. Already we are zoned for light industries and these are food manufacturing industries," Muregi who is a lecturer with Mt Kenya University said.
The residents have written to the National Environment Management Authority asking the agency to assist them to conserve the environment.
They say the ever swampy region around Uplands, Nyambare, Shauri, Gituamba and Raini Njeke is the source of tributaries that drain waters to Ruiru Dam.
The Ruiru Dam, which is managed by Nairobi Water and Sewerage Company, supplies residents of Kiambu town and parts of Nairobi with clean water.
Muregi said locals grow cabbages, kales, spinach, fruits while others rear dairy cows and pigs.
Paul Wainaina, a resident, asked President Uhuru Kenyatta to visit the area and hear their pleas.
Speaking on Monday at Uplands swamp Njoki Wamitugo and other group officials, said they want to start teaching locals ways of conserving the environment.
"Once we start, we shall involve all environment stakeholders so that locals can understand the impact that might be left," Wamitugo said.
She added, "If we are zoned, our air will be polluted, the water sources, Uplands Bacon Factory which is run by Farmers Choice will also be affected. Others are Uplands forest."
Wamitugo urged the investor to start a food processing industry and concentrate with foods grown in the area adding he will be getting an adequate supply.
"If we practice value addition of what is grown in this region, am sure the supply will be more. It will also impact to locals to practice modern technology in farming and thus create more employment and make people busy in their farms," she added.
