Skip to content

River bank protection using polymer gabions – A case study on the river Tapi in India

Reliance Industries Limited commissioned their plant at Hazira in the year 1991. This plant is located in Choryasi Taluka in Surat District in the state of Gujarat, and is an integrated facility manufacturing different petrochemicals and polyester intermediates. A coal based captive power plant has also been planned in the same complex in order to provide an economical alternative to the facilities’ power requirements. The entire complex sits on the banks of the river Tapi. The Tapi river is a large river originating in Central India and running westwards for a length of 724 km, before discharging in to the Gulf of Khambat. The entire complex rests on a stratum of “deep black soils” which comprise mainly montmorillonitic clays. Over the course of the past 25 years, the river has slowly eroded the boundary of the entire complex for a length of almost 900 m. Almost 2.0 acres of land have been lost by the facility. In order for the captive power plant to be constructed, it was necessary to protect the facility from the ravages of the meandering river Tapi. The risk of a breach in the bank endangering the captive power plant was too large to be ignored. The typical morphology of the site also meant that traditional solutions would not work. A bank protection with sheet piling had been taken up successfully earlier in an upstream facility. A “soft” solution using a combination of polymer gabions, geo-textile bags and PVC coated metal gabions was preferred as a technically equivalent but cost effective solution to traditional sheet piling. The solution was designed and installed successfully at a much lower cost than sheet piling. The structure has withstood two monsoons with minimal maintenance and is today a good example of a “living structure” with different flora and fauna that have beautifully intermeshed with the structure. This paper highlights the design philosophy, structural design as well as installation aspects of the river training system