India: Mizoram State Roads Project
August 1, 2011
Using Bioengineering to Stabilize Landslide-Prone Hillsides
One of the major challenges in building hill roads is stabilizing hill slopes with appropriate and costeffective interventions. The Mizoram State Roads Project in India employed innovative bioengineering techniques that used the abundantly available local bamboo to stabilize the hill slopes at a fraction of the cost of conventional methods that use concrete structures for the purpose.
Bioengineering is the use of vegetation, mostly shrubs and grasses, either alone or in conjunction with stone and concrete protection works such as retaining walls etc. to enhance the stability of slopes. It benefits both road building agencies and users alike as it not only provides one of the best, and cheapest, ways to protect the road and its users from landslides, but also retains the hillside’s productivity, unlike stone and cement works on which no vegetation can grow. A slope treated with bioengineering measures can therefore retain its forests, water bodies, farmlands and orchards while also covering up any unsightly scars that result from road widening activities. These environmentfriendly measures also reduce the carbon footprint of roads.
Bioengineering techniques are now being implemented under the World Bank supported Himachal Pradesh State Roads Project.