Natural Effect of Classical Check Dams in the Torrents of The River Toplica Drainage Basin

The effects of check dams for torrent control were analysed in the river Toplica drainage basin, upstream of the future water reservoir "Selova" in the central part of Serbia. The effects were analysed from the aspect of bedload retention, decrease in the natural bed slope, and the stabilisation of the torrent channel. Special analysis was focused on the conditions and criteria of forming the slope of siltation and the methods of its calculation in the function of the correct determination of the distance between check dams. It was shown that some formulas for the calculation of the slope of siltation produce results which differ very much from the real slopes of siltation. The best agreement with the real slopes of siltation was obtained by the calculations based on the regional analytical dependence obtained by the statistical analysis of the dependence of the slope of siltation on natural bed slope. The research shows that all check dams are stable and, regardless of the retained bedload, they contributed to the stabilisation of the torrent channel.