The directorate of soil conservation will implement projects on three hillocks of the city to check soil erosion, which is expected to cost Rs 5 crore.

The state forest department, IIT Guwahati, Guwahati Municipal Corporation (GMC) and Guwahati Metropolitan Development Authority (GMDA) will collaborate for implementation of the projects.

Gitanagar, Jyoti Nagar and Kahilipara hillocks have been selected initially for implementation of the projects.

“The idea is to check the downhill flow of water and reduce its speed till it falls in the drains. When the water comes down at great speed, it carries with it silt that clogs the drains,” additional director of directorate of soil conservation Jiten Malakar said.

“We are working on ideas like checking the speed of water cascading down a hill and then channelling it into the drains, being constructed on the hills. With the help of silt trapping, rainwater will not carry the silt to the main drains of the city. Blanketing the slopes with jute nets will further strengthen the slopes against erosion. The jute nets will have holes in it to help plants grow and strengthen the slopes. However, the nets will decompose with time,” Malakar said.

Guwahati has around 366 sites which are vulnerable to soil erosion. Last year, the district administration carried out mass awareness programmes on different vulnerable sites.

A campaign was organised by the directorate of soil conservation on its premises in the city on Thursday where officials of the Assam State Disaster Management Authority (ASDMA), Assam Engineering College (AEC) and the zoo were present.

“People living on the hills can construct their own water reservoir. They can channel the flowing water into the reservoir. People should check all aspects, especially safety, while building a house on the hills. Earth-cutting near a slope should also take place without harming the stability of the soil and the slope,” AEC associate professor Diganta Goswami said.

“The drains in Guwahati, designed according to the earlier population of the city, should now be modified. The drains are also not linked with each other. Excessive water in a particular drain cannot make way to other drains. Retaining walls on a slope should have weep holes so that water can seep from a particular household to the drains. Walls without holes will build up pressure on the loose soil which may result in the wall to cave in,” an ASDMA official said.