Sediment Transport Issues Related to a Planned Cross-cut through the Vistula Spit, Poland

In order to make a navigable connection between the Vistula Lagoon and the Baltic Sea independent of an attitude of the Russian authorities, a cross-cut in the Polish part of the Vistula Spit is planned. The cross-cut will constitute an alternative waterway with respect to the existing one, leading through the Pilawa Strait which belongs to the Russian territorial waters. The new outlet will require breakwaters and an approach channel on the open sea side, as well as a waterway across the Vistula Lagoon to the harbour of Elblig. The planned cross-cut is located about 3 km from the root of the Vistula Spit, at Skowronki village. The paper comprises an analysis of regional wave parameters in a mean statistical year on the basis of the Baltic wave climate reconstructed for the period of 44 years, together with a calculation of the longshore sediment transport rates. An influence of the planned coastal structures on the shoreline evolution, as well as the approach channel silting-up rates, in the first 10 years after the construction of the cross-cut, are estimated. An optimised layout of the planned approach channel and lengths of the planned breakwaters are recommended to facilitate the maintenance of the coast and the new waterway.