HD adopts novel methods to stop Nilgiris landslips

COIMBATORE: To mitigate landslides along the Ghat Road in The Nilgiris, the State Highways Department has undertaken innovative solutions such as soil nailing, hydro-seeding, and geogrid works.

The highways department has started implementing these measures in landslide-prone areas along the Ooty-Kotagiri-Mettupalayam Road for better stabilisation of slopes.

Public Works Department (PWD) and Highways Minister EV Velu and Tourism Minister K Ramachandran recently launched the new projects at Kodappamund on the Ooty-Mettupalayam Road.

Soil nailing is a geotechnical engineering technique that involves the insertion of iron bars into the soil for strengthening. Hydro-seeding involves growing grass on the soil to prevent erosion and the geogrid method is installing knitted steel mats on the slopes.

The soil nailing technique is cost-effective and also environmentally friendly. A total of 284 spots were identified to be landslide-prone in the Nilgiris.

This method is likely to be implemented in Kodaikanal and Yercaud hills based on its success in the Nilgiris.

“The retaining wall construction hampers the growth of greenery. As an alternative, the three-dimensional steel wire mats will be spread over the slopes above the seeding and tied to soil nailing,” explained a statement. Besides the Nilgiris, the soil nailing technique is being implemented in Valparai Hills, Kolli Hills, and Yercaud Hills to prevent landslides.

More than 25 families died in a major landslide due to a cloud burst on 25 October 1990. Similarly, hundreds of people died in a landslide following a cloud burst at Marapalam on 11 November 1993, while 42 persons died in continuous incidents of landslides within 48 hours in Ketti in 2009 due to heavy rains following the North East monsoon.