The area under study in this paper was subject to landscape transformations, including changes in hydrographical networks. These changes were especially intense in the second half of the 19^th century during the Prussian partition, when extensive hydrotechnical works were conducted. Based on a comparison of cartographic materials at a scale of 1:25,000, Prussian topographic maps from 1874, and Polish maps from the second half of the 20^th century, it was found that the hydrographic network has changed significantly. A characteristic anthropogenic pattern of water structures was observed that correlates with certain individual morphological units. In the bottoms of the valleys and hollows there is a dense irrigation network, and in the moraine areas, numerous reservoirs of anthropogenic origin were found that are characterized by a rather small size and circular shape. The drainage density in the area under study has increased from 0.7 to 1.95 km·km^-2, but the lake percentage has only increased from 1.81 to 1.93%. However, the number of reservoirs has increased from 36 to 675. The anthropogenic water reservoirs were found first and foremost in the area of the uplands, where the reservoir frequency has increased from 0.3 km·km^-2 to 7.7 km·km^-2.
The results of the conducted research can be used to perform an automatic analysis of the transformations of the water network in Tuchola Forest and other areas of the last glacial extent. The results of the study presented in this paper should also be used when taking any decisions and actions that may lead to changes in water network and water management. The discussed “anthropogenic lakeland” located in the area of poor industrial and urban development, the Tuchola Forest, may also be the premise for verifying views on a large number of lakes situated in kettle holes within the Polish Lowland (Niż Polski).