Here the Dnieper assumes all the characteristics of a plateau river. The river valley becomes so narrow that at high-water the river spreads over the entire valley bottom. The settlements take refuge on the heights of the steep bank. The granite-gneiss sub-layer appears in steep precipices and high picturesque rock formations on the valley slopes. We are confronted with the same caflonlike valley on the Dnieper, then, as on the Dniester in the Podolian Plateau. Yet there are certain fundamental differences. The river valley is at most 100 meters deep, and the granite slopes do not form compact valley sides such as we see in the yars of the Dniester. At every moment the steep decline is broken by numerous gorges, picturesque foothills; and jutting cliffs lend to the river landscape of the Dnieper Valley, at this point, a variety unknown in the yar of the Dniester.
The section of the Dnieper River from the mouth of the Samara to Veliki Luh, at the mouth of the Konca, forms a river country which is the only one of its kind in Eastern Europe. It is the section of the Dnieper rapids. The post-tertiary elevation of the Ukrainian horst, at this point, has forced the river to dig its bed into the hard granite and gneiss rocks. Despite great masses of water, the river has not succeeded in equalizing its incline. For this reason, we find in its bed innumerable rocky islands, ledges of rock, separate cliffs and great boulders. In a wild, roaring torrent, the current beats against these obstacles, creating deep pools and dangerous vortices. But not at all places was the river destined to saw thru the obstacles in its way. At many points solid ledges of rock lie right across the river. Its mass of water falls down over these granite steps in immense foam-wreathed bilows and seethes about innumerable boulders, remains of already parted ledges. The dull roaring and rumbling can be heard, even by day, for several miles. These are the rapids of the Dnieper — the "porohi" and "zabori."
The porohi are not real waterfalls or cataracts; the incline of the river in this section is 35 meters for a stretch of 75 km., and is, therefore, too slight for regular falls. The greatest incline attained within this stretch of river is
6%. Therefore, only the individual branches of water between boulders form small falls, while the main channel only shoots along down-stream in a long, foam-covered streak, over the inclined surface of the ledges. In summer, the depth above the rock ledges is barely 1 Yi meters, while in the spring even the highest reefs of the rapids disappear beneath the masses of the high-water.
Still, the rapids of the Dnieper are even now a great hindrance to navigation. Within the porohi section, steamboat navigation is altogether impossible, and the smaller rowboats or sailboats can risk it only during the spring floods, and then only the down-trip. Only the rafts can pass thru the porohi at low-water time, altho with great danger. The up-stream trip is almost impossible, even in the smallest vessel, altho, at one time, everyone who desired to join the Zaporog Cossacks was required to undertake this daring enterprise.
The Russian government has attempted, indeed, to make the rapids of the river navigable, and has caused a navigable canal to be formed at each fall, thru blasting of the rock ledges. But these canals have been planned in so impractical and even faulty a manner that the river pilots (lotzmani) still use the old "Cossack paths" to a great extent (the Cosachi khody) to bring river boats and rafts thru the porohi.
The width of the river in the rapids section remains unchanged — 1 to 1 % kilometers. Only at its exit from the porohi, at the so-called Wolf's Throat (Vovche horlo), the river narrows down to 160 meters. The quiet sections between separate rapids are usually very wide and as much as 30 meters deep.