The goal of the project is developing new strategies for conditioning of mud for making sediment navigable. In contrast to reallocation of sediment, conditioning is used for port maintenance assuming that the sediment stays in the port area. The goal of conditioning the sediment is to create navigable conditions in waterways while keeping the sediment in place. In this case, the nautical bottom concept is often applied for navigation through mud. One of the most efficient examples for applying sediment conditioning for port maintenance is in the Port of Emden. The sediment is conditioned by reducing the strength of dredged sediment by re-circulation process. Rheological properties (i.e. yield stress) provide a reliable criterion for nautical depth definition since they are related to the stress history and shear of the mud. During re-circulation, dredged sediment is first collected by a hopper dredging vessel and then pumped back to the port area creating a navigable fluid mud layer. If the transport of fluid mud towards the river equals the import of suspended mud by exchange flows, a dynamic equilibrium is achieved without residual import, hence dredging.