Summary:

A stream running through a settlement or town can create great hazard to the adjacent development areas; it is also, however, a natural decorative element.
Because of time passing and lack of necessary maintenance of the structures, their rebuilding and modernization is often necessary. Here many problems arise. They include: lack of place for the required expansion of the river course and cross-sections, geological structure, requirements of the valid water and building law, architecture (especially in old-town development), and ecology. An approach to solve these problems is presented in the paper for a large stream of Wątok running through the old part of the Tarnów town. Because of the location of the stream, intensive urban development and the neighborhood of sacral buildings protected by law, it is the urban authorities' responsibility to ensure full safety to the neighboring land. This task was undertaken as early as in the mid-war years although the protection level was inadequate. The technical condition of the structures threatening to cause building catastrophe, and the aesthetics of solutions were additional arguments to undertake the project.
To give the reader an illustration of the multiplicity and importance of technical problems of the designed development, the existing state being different in different sections of the stream development and solution proposals were discussed an the two-part paper. The illustrative drawings and photographic documentation help to understand the merits discussed in the paper.