A team of TN public works department (PWD) engineers will visit Mullaperiyar Thursday to fill holes dug by experts to study structural safety of the dam.

Principal secretary (PWD) M. Saikumar said the work would be completed in four days starting Thursday. The experts appointed by a Supreme Court-constituted empowered committee (EC), which studied safety of the 116-year-old structure, reportedly dug seven six-inch wide and 130-190-foot deep holes across the 1,200-foot main dam.