The Ukrainian rivers are genuinely typical of Eastern Europe. The great uniformity of the surface configuration of the Ukraine is responsible for the lack of that variety in its own river system which characterizes the waters of Western and Central Europe. But the great extent of the land does cause the Ukraine to have mountain, plateau and lowland streams, so that it does not attain the degree of uniformity in hydrographic conditions of Russia proper.
The Ukrainian river system concentrates in the Black Sea. From northwest, north and east, the rivers of the Ukraine tend toward its sea. Besides, the western boundary lines of the Ukraine lie on the Baltic slope. There, in Podlakhia, in the Kholmshchina, on the San River and in the Lemko country, the Ukrainian people has had its seats since the dawn of its history. In most recent times Ukrainian colonization has gained also parts of the Caspian slope on the Kuma and Terek Rivers. But the region drained by the Black Sea surpasses both the other regions so much in extent and in the size of its rivers, that the Baltic and Caspian region of the Ukraine dwindle in comparison. Nature has, therefore, turned the Ukrainian nation toward the south and southeast to the Black Sea. But, at the same time, she has not denied the Ukraine a convenient connection with the north and south of the globe. The main European river divide is, perhaps, nowhere so flat and so easy to cross as in Ukrainian territory. From the Dniester to the San (bifurcation of the Vishnia creek near Rudky), from the Pripet to the Buh and Niemen the passages are easy. Since ancient times portages have existed here, and in modern times the Pripet has been connected with the Buh and the Niemen by means of canals (King's Canal and Oginski Canal) which, however, are at present entirely antiquated and almost useless. Besides, the widely branched water system of the Dnieper outside the Ukraine affords easy passage to the Dvina (Beresina Canal), Volga and Neva, in White Russian territory. Over these waterways and the portages lying between them the old path of the Northmen led from Scandinavia to Constantinople. This most important aspect of the Ukrainian water system promises at some future time to bear rich fruit, if the recently-formed plan to build a waterway for navigation on a large scale, from the Baltic to the Black Sea, utilizing the course of the Dnieper, should become a reality.
The Baltic watercourses of the Ukraine flow into the Vistula. Several large Carpathian tributaries originate in Ukrainian territory. Here the rapid Poprad carries the melted snow of the Tatra to the Dunayetz. The source of the Visloka also lies in the Ukrainian Lemko country. The last and largest Carpathian tributary of the Vistula belongs, in three-fourths of its extent, to Ukrainian territory, namely, the navigable San. It receives from the Carpathians the Vislok on the left and the Vihor on the right. The other tributaries of the San on the left side, the Vishnia, Sklo, Lubachivka and Tanva, come from the sub-Carpathian country and the Rostoche Plateau.
All the Carpathian tributaries of the Vistula have only at their sources the character of mountain streams, with swift currents, in rocky river beds, lined by banks of waterworn material. Even in the mountains their valleys become wide, covered with banks of pebbles, sand and loam, and overgrown with willow-brush, and their falls insignificant. In the sub-Carpathian country the banks become low and sandy, the stream slow, and the waterlevel is very unsteady, owing to the cutting down of forests in the country of the source. In spring, when the snow melts in the mountains, and at the time of the early summer rains, there are terrible floods; in dry summers the rivers dwindle to almost insignificant proportions.
From the Rostoche the Vepr, navigable from Krasnostav down, flows thru a broad, marshy valley, into the Vistula. The northern declivity of the Podolian Plateau sends its largest river, the Buh, navigable from Sokal on, down to the Vistula. This river is really a genuine lowland river. Its valley is wide and flat, the river winds with its muddy bed thru forest marshes, thickets of reeds and willow brush, now parting into a dozen branches, now flowing in a wide bed, past fresh, green meadows and dark forests. The same lowland character is a common quality of the left-hand tributaries of the Buh, the Poltva, Rata, Solokia, Krna and of the Luha on the right hand. The Mukhavetz, Lisna, Nurez and Narva, on the other hand, are typical woodland streams, which roll their great mass of water thru the forests of Podlakhia.
The Pontian Rivers of the Ukraine belong to the six great regions drained respectively by the Danube, Dniester, Boh, Don and Kuban.