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 ...
The content of this paper is the continuation of the paper presented in the previous volume. The necessity of flood protection of urban areas was argued and the attention was paid to environmental and small architecture aspects. A typical solution that was discussed concerns the re-development and renovation of a stream of Wątok flowing through the old part of the Tarnów town with monumental sacral buildings. First regulation works were undertaken in the mid-war period. Time passing, water aggressiveness intensified with municipal wastes, and the lack of proper maintenance caused considerable damage to the existing structures. The extent of the damage threatened building catastrophe with all resulting consequences.Utilizing own resources and the acquired PHARE funds, the Tarnów authorities decided to undertake full-scale works on the stream reach under discussion. High requirements were posed concerning the environmental and aesthetics conditions with the simultaneous meeting the safety conditions of the neighboring terrain and the development itself. Because of varying character and technical state of the existing development, as well as different land conditions and the character of ...
This paper aims at sharing feedback about dry dams. These structures are efficient to mitigate floods, while little disruption of the continuity of the main channel and its flows outside the flood periods. Five sets of dams are presented here. They were selected so as encompass the diversity of the structures and of the problems. The oldest structures are presented first. These are dams built in the beginning of the twentieth century in Poland and in the USA, which are still in operation today. Then, recent realisations in France are presented. Large dams in Gard catchment and small dams upstream the nearby town of Nîmes are described, with analyses of behaviour during intense floods. Finally, small dams in Seine-Maritime allow to address the issue of an efficiency diagnostic at catchment's scale, when both dams and stakes are spread out. This article gives key references for further information about structures design. ...
The one of the Polish rivers richest in water with substantial flood hazard and important hydro-energy potential. Two large flood protection and hydroenergy schemes were constructed on the Upper Dunajec: Rożnów-Czchów and Czorsztyn-Sromowce Wyżne. Lower Dunajec extends downstream from the Czchów hydraulic barrage to the outflow to the Vistula and is 67.4 km long. Construction of two large hydraulic schemes resulted in the increase of the low and average discharges, however, simultaneously important disturbance of sediment transport occurred. A large amount of sediment is deposited in the reservoirs. As the result of this process, significant erosion was observed along the Lower Dunajec reaching in some places even 4 m. This process was increased by the sediment exploitation from the river channel. Due to flood problems several training works were executed along the Lower Dunajec. All these resulted in lowering of the river channel, which became a draining river. Stabilization of the river channel is possible by means of the construction of special weirs with inflatable gates. Construction of the weirs gives the possibility of using heads for hydro-energy. It is proposed to construct small hydraulic power plants, which would operate during low and average discharges. ...
