Soil erosion is the major challenge in compacted clay intermediate cover liners of engineered landfills. The severity of erosion depends on many factors, including the angle of inclination of the slope, intensity of rainfall, duration of rainfall, and properties of the soil. An appropriately designed cover material can be a solution for the erosion problem. The study proposes biopolymer-modified geomaterials as a sustainable cover material for engineered landfills. In the current research, xanthan and guar biopolymers were selected based on their properties of non-toxicity, economic feasibility, and market availability. Parameters like index and engineering properties of soil before and after treatment with biopolymer, and rainfall-induced erosion characteristics of the selected soil were observed. For studying the rainfall-induced erosion, a bench-scale laboratory test was carried out. An apparatus was set up in the laboratory to simulate artificial rainfall on an inclined slope as per ASTM standards. It was seen that the percentage of soil eroded was drastically reduced in the case of biopolymer-amended soil. Furthermore, the liquid limit and plastic limit of the soil were increased upon treatment. The unconfined compressive strength of the parent soil was also enhanced. On the basis of the results, it was observed that although the xanthan gum-treated soil sample exhibits higher strength values, the guar gum-treated soil sample shows higher erosion resistance.