The fluvial system of Moravia is very cohesive, as the region border is similar to the watershed of the Morava river, and thus almost the entire area is drained exclusively by a single stream. Morava's far biggest tributaries are Thaya (Dyje) from the right (or west) and Bečva (east). Morava and Thaya meet at the southernmost and lowest (148 m) point of Moravia. Small peripheral parts of Moravia belong to the catchment area of Elbe, Váh and especially Oder (the northeast). The watershed line running along Moravia's border from west to north and east is part of the European Watershed. For centuries, there have been plans to build a waterway across Moravia to join the Danube and Oder river systems, using the natural route through the Moravian Gate.