Poziomowanie linii spławnej na Kanale Augustowskim – analiza systemu śluz

The year 2024 marks the 200th anniversary of the commencement of construction work on the Augustów Canal. This anniversary invites us to reflect on the current state of knowledge concerning the creation of one of the most interesting hydraulic engineering projects of the first half of the 19th c. This complex has survived to the present day and, as a historical monument, is considered one of the most valuable technical monuments in Poland. In this article, we would like to address several issues related to the process of geodetic determination of ground ordinates. In cartographic terms, we presented the types of maps that had the level drawing needed to determine the route of the canal and the heights of the surrounding lakes. They testify to the use of trigonometric levelling and are an important testimony to the cartographic and engineering skills involved in the process of route reconnaissance, planning and construction of the aforementioned canal. The research method was to collect period data on the drop heights (water level differences) occurring at each lock. After converting them into metric data, we compared them to the currently collected material. It turns out that the total drop from Dębowo sluice to Niemnowo sluice was 59.09 metres, which is more than three metres higher than today. These calculations show the efforts of the builders and engineers who connected the Narew River with the Nemunas along 174.2 km of the canal. These calculations also allow us to assess the value of the retrogressive method often used in historical research.