Late Quaternary terraces and sediments in the Holy Cross Mountain region of Poland, emplaced within an environment that had evolved following multiple Pleistocene glaciations, provide evidence of increasing anthropogenic influence on landscape development since the Middle Ages, as revealed by research in the Kamionka, Kamienna, Czarna Konecka, and Nida valleys. The development of the “anthropogenic small-scale water retention system” (ASWRS), including numerous artificial ponds, channels, and forges and mills along the watercourses, resulted in changes in river patterns, with additional anthropogenic channels, which in turn reduced the maximum flood-stage levels during the Little Ice Age. With the collapse of the industries and the disappearance of the ASWRS, several major flood events took place. Unknown in the earlier Holocene, and caused by hydrotechnical failures, the geomorphic effects of these catastrophic flash floods significantly exceeded those of natural processes.
