This article presents hydrological aspects of a renaturization plan for a river valley that has been significantly transformed as a result of human impact. A section of the Szarlejka River valley located at the border of the cities of Bytom and Radzionków was used for this purpose.
The hydrographic conditions of the area under consideration have been significantly altered due to human action. These transformations are the result of systematic residential and industrial infrastructure development, which has been accompanied by industrial waste disposal. Underground coal mining in the area has caused subsidence and discharge of saline mining waters to rivers. The Szarlejka is considered one of the most polluted rivers in Silesia Province (Polish: województwo śląskie) and all of Poland.
The primary objective of the renaturization plan is to improve abiotic conditions and water status. This plan is based on the analysis of all accessible data, including archival maps and field work. Hydrological and hydrotechnical renaturization actions are proposed for the Szarlejka River valley that cover the elements, structures, and facilities, of which the mere presence brings the waters closer to their natural state (barrages inhibiting erosion, connections allowing for the circulation of aquatic organisms). The proposal also includes building astatic reservoirs, creating oxbow tanks in retained sections of the old river bed, and building a pond with a wetland and an island.
The restored structures will affect abiotic and biotic conditions, consequently influencing the water recovery process with the aim of bringing it closer to its natural state.
For the purposes of the planned renaturization, a geographic information system (GIS) was created, enabling digital map generation, database creation, and calculations.