Crud Matrix refers to the soil of a riverbank, formed as a result of constant flow through water erosion. The soil is extremely hard and can be shaped only by large movements. The crust may be several centimeters thick or more but it never exceeds six meters deep. This is why it cannot pose any threat to the environment. However, the formation of crud matrix brings out environmental problems like blockage in the riverbed and its banks, which cause serious damage to navigation works and public utilities in particular. CRUD stands for C (for clay), R (for rock), U (for unstable substrate) and D (for depth).