Cut-off Walls create barriers to ground water inflow or subsurface contaminates. Many types of cutoff walls exist, such as slurry diaphragm walls, secant pile walls, sheet pile walls, jet grouting walls and ground freezing.

Cutoff walls are typically used to reduce seepage beneath dams or levees, construct water resistant excavation pits, or enclose contaminated areas within brownfields or mines. Slurry walls and certain types of grouting methods, including jet grouting, may be good options for dams or deep excavations.