Sheet pile cutoff wall is used in all types of water retaining structures to reduce the exit gradient at the downstream toe and prevent the chances of sand boiling and piping. It is used for excavation bracing and dewatering applications. It can be made of wood, reinforced concrete, or steel, with steel being the most effective material for constructing a ground-water barrier. The construction of a sheet pile cutoff wall involves driving interlocking sheet piles down through unconsolidated materials to a unit of low permeability.