The document summarizes a study on the effect of coir fiber on the piping behavior of soil. 1-D piping tests were conducted on unreinforced soil samples from Idukki district in Kerala as well as samples reinforced with varying proportions (0.5%, 0.75%, 1%) and lengths (1.5-6 cm) of coir fiber. The tests measured seepage velocity, piping resistance, and other parameters under different hydraulic heads. Results showed that a fiber content of 1% and length of 4cm was most effective at reducing seepage velocity and improving piping resistance by replacing soil particles and blocking pore spaces. Reinforced samples demonstrated higher resistance to piping initiation and development